Car Battery

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Namashkar
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Car Battery

Post by Namashkar » Tue Jan 08, 2019 5:00 pm

Hello,

I am planning to be away for a few months while my car is not going to be used. Since some BHs may have experienced same issue I was wondering how they handled it. I am thinking about removing the wires from battery terminals so the electronics may not drain the battery. In one previous occasion my battery drained and I needed a jump which was I convenient since the car was parked in the garage. I am not good at auto things, would I just uncable one terminal and if so which one (+ or -)?

Thanks,

pqwerty
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Re: Car Battery

Post by pqwerty » Tue Jan 08, 2019 5:08 pm

Could use a battery tender as well.

brianH
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Re: Car Battery

Post by brianH » Tue Jan 08, 2019 5:10 pm

Your best bet is to remove both battery connection terminals and get a 'trickle charger' that you then connect to the battery. This will very slowly replenish the charge as it sits. Many auto stores or Amazon have choices that should run you about $20.

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LadyGeek
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Re: Car Battery

Post by LadyGeek » Tue Jan 08, 2019 5:10 pm

Namashkar - You had a duplicate post, which I've removed. There were no replies. This isn't a big deal, don't worry about it.

(Thanks to the member who reported the post. One of the reasons is "Duplicate thread".)
Wiki To some, the glass is half full. To others, the glass is half empty. To an engineer, it's twice the size it needs to be.

neilpilot
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Re: Car Battery

Post by neilpilot » Tue Jan 08, 2019 5:13 pm

brianH wrote:
Tue Jan 08, 2019 5:10 pm
Your best bet is to remove both battery connection terminals and get a 'trickle charger' that you then connect to the battery. This will very slowly replenish the charge as it sits. Many auto stores or Amazon have choices that should run you about $20.
Actually you are best served by connecting the trickle charger while the battery remains connected and in the car. Not only is this easier, but car's systems (primarily your radio) will retain their memory while the battery is maintained at a suitable charge.

iamlucky13
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Re: Car Battery

Post by iamlucky13 » Tue Jan 08, 2019 5:16 pm

FYI, many Hondas, and probably other cars, disable the radio as an anti-theft measure if battery power is lost. With the amount of electronics in newer cars. Changing batteries can involve providing a separate power source to the radio momentarily, or getting a code from Honda to reactivate the radio.

If you do disconnect, do so with the negative terminal first.

Be aware that even if disconnect, lead acid batteries slowly experience self-discharge. It's highly unlikely to completely drain in a few months, but lead acid batteries have the longest service life if kept at full charge. A good way to do this is a trickle charger or maintainer like Battery Tender, as long as you have an outlet nearby.

I saw the Battery Tender Junior listed on sale at Costco recently. It might have been the latest ad.

bob60014
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Re: Car Battery

Post by bob60014 » Tue Jan 08, 2019 5:18 pm

Battery Tender, keeping the cables attached. When the cables are disconnected on some cars, the engine cpu may also be drained. If it is, when restarted the engine goes through a relearning process and may run rough for the first 15 minutes. Ymmv.
Last edited by bob60014 on Tue Jan 08, 2019 5:27 pm, edited 2 times in total.

fittan
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Re: Car Battery

Post by fittan » Tue Jan 08, 2019 5:20 pm

A battery tender cost about $30. A portable battery jumper about $60.

I would get the latter and let battery drain. If it battery is dead, the portable jumper can easily start it up. After that keep it in car for emergency (to jump battery, charge iphone, flash light etc).

https://smile.amazon.com/GOOLOO-SuperSa ... mp+starter

brianH
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Re: Car Battery

Post by brianH » Tue Jan 08, 2019 5:20 pm

neilpilot wrote:
Tue Jan 08, 2019 5:13 pm
Actually you are best served by connecting the trickle charger while the battery remains connected and in the car. Not only is this easier, but car's systems (primarily your radio) will retain their memory while the battery is maintained at a suitable charge.
Is that a good idea with modern, sophisticated battery 'tenders' that do more than just provide a constant current? I always assumed that the 'vampire' loads of the misc electronics would interfere with the tender's sensing logic.

Either way, not much of value is lost if the car is without power. Many of the modern car electronics store memory in non-volatile storage.

neilpilot
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Re: Car Battery

Post by neilpilot » Tue Jan 08, 2019 5:24 pm

fittan wrote:
Tue Jan 08, 2019 5:20 pm
A battery tender cost about $30. A portable battery jumper about $60.

I would get the latter and let battery drain. If it battery is dead, the portable jumper can easily start it up. After that keep it in car for emergency (to jump battery, charge iphone, flash light etc).

https://smile.amazon.com/GOOLOO-SuperSa ... mp+starter
A very bad idea. The dead battery will sulfonate and likely be ruined. It will also freeze if exposed to winter conditions.

btenny
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Re: Car Battery

Post by btenny » Tue Jan 08, 2019 5:24 pm

Unhook the positive cable and move it away so it does not touch the battery. Most standard car batteries will maintain a charge when stored like this for 3 months or so. Then when you get back home you just hook the battery up to the car and it should start. Make sure you let the car run at slow idle for a few minutes after it has been stored like this before driving it.

After storing the car check the tires and look over the car to make sure everything is OK before driving it. I killed a good tire once when I drove around my neighborhood with a flat after a long storage. Also be aware that tires develop "flat spots" from setting long term on one spot. This will cause them to "thump" when you drive the car next time. And depending on the tires and and time setting and temperature this thumping may not go away after driving the car for a few miles. There are roll on tire protectors to minimize this issue. I have not used them so I do not know how well they work.

Also add a can of gas stabilizer to the full gas tank before leaving and storing the car for long periods. This will keep the gas Ok for 6 months or more.

Good Luck.

RickBoglehead
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Re: Car Battery

Post by RickBoglehead » Tue Jan 08, 2019 5:26 pm

I agree, it's a very poor idea to let the battery discharge.

A Battery Tender is the proper solution.

neilpilot
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Re: Car Battery

Post by neilpilot » Tue Jan 08, 2019 5:28 pm

brianH wrote:
Tue Jan 08, 2019 5:20 pm
neilpilot wrote:
Tue Jan 08, 2019 5:13 pm
Actually you are best served by connecting the trickle charger while the battery remains connected and in the car. Not only is this easier, but car's systems (primarily your radio) will retain their memory while the battery is maintained at a suitable charge.
Is that a good idea with modern, sophisticated battery 'tenders' that do more than just provide a constant current? I always assumed that the 'vampire' loads of the misc electronics would interfere with the tender's sensing logic.

Either way, not much of value is lost if the car is without power. Many of the modern car electronics store memory in non-volatile storage.
Bought this for $22 back in August....a bit more now.
https://www.amazon.com/gp/product/B076Q ... UTF8&psc=1

Works fine, and does not have a problem with "vampire" loads. As mentioned above, some car radios will revert to security code recovery if the battery is disconnected.

TLC1957
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Re: Car Battery

Post by TLC1957 » Tue Jan 08, 2019 5:31 pm

Battery tender is what I do when we go sit in the sun while the car has snow on it for 3 months. Do not forget to check the water level in the battery when you get back, yea that maintenance free battery still needs water ( distilled). Look at the battery if it has covers that can be lifted off you need to add water. If the car if far from the house pull the battery out and use the tender, but as others have said charge the battery while it is connected to the car.


This is what I purchased

https://www.amazon.com/gp/product/B000F ... UTF8&psc=1

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vectorizer
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Re: Car Battery

Post by vectorizer » Tue Jan 08, 2019 5:45 pm

Don't disconnect anything, just connect a smart but simple battery "tender" to the battery, the same way you'd connect jumper cables, then of course plug the tender into a wall outlet. I've used this one for many years:
https://www.amazon.com/Battery-Tender-0 ... nder&psc=1

As long as your car will have been driven within the previous few days, a small 1 amp tender like this is all you need.

killjoy2012
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Re: Car Battery

Post by killjoy2012 » Tue Jan 08, 2019 5:56 pm

Just buy a battery tender, hook it up and be done. No need to disconnect the battery from the vehicle.

sport
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Re: Car Battery

Post by sport » Tue Jan 08, 2019 6:16 pm

If you decide to disconnect the battery, just disconnect the negative (grounded) cable. Disconnecting one cable is sufficient. Disconnecting the positive cable can be very dangerous while the other cable is still connected. When disconnecting both cables, always disconnect the negative cable first, and when reconnecting, connect it last. Disregarding these instructions can cause the battery to explode. Always always always wear eye protection when doing anything with an auto battery.

sport
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Re: Car Battery

Post by sport » Tue Jan 08, 2019 6:18 pm

btenny wrote:
Tue Jan 08, 2019 5:24 pm
Unhook the positive cable and move it away so it does not touch the battery.
NO!!! This is dangerous. Disconnect the negative cable.

Smoke
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Re: Car Battery

Post by Smoke » Tue Jan 08, 2019 6:23 pm

https://www.harborfreight.com/Automatic ... 69955.html

Goes on sale for 4.99 often.

I have been using these for years 2 cars, and 2 mowers. Keeps car battery at 100% without overcharging, months at a time.

iamlucky13
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Re: Car Battery

Post by iamlucky13 » Tue Jan 08, 2019 11:27 pm

brianH wrote:
Tue Jan 08, 2019 5:20 pm
neilpilot wrote:
Tue Jan 08, 2019 5:13 pm
Actually you are best served by connecting the trickle charger while the battery remains connected and in the car. Not only is this easier, but car's systems (primarily your radio) will retain their memory while the battery is maintained at a suitable charge.
Is that a good idea with modern, sophisticated battery 'tenders' that do more than just provide a constant current? I always assumed that the 'vampire' loads of the misc electronics would interfere with the tender's sensing logic.
Their logic is actually not terribly complicated. They basically check the battery voltage. Full featured models like the Battery Tenders will maintain a fixed charge rate when the voltage is below a certain level in order to speed the charging. When it hits a certain voltage, they maintain that voltage to top off the battery. While that is going on, the current the battery draws slowly declines. When the current drops to a set level, they then either switch off until the voltage drops below a threshold for topping again, or they drop to a float voltage.

The Battery Tender Jr does the latter, practically speaking, although when I measured mine I noticed it actually pulses on and off at a regular interval at float voltage. I'm not sure why they do that - if it has benefits for sulfation prevention, simplified the circuit design, or something else.

The Harbor Freight model someone linked above, according to the manual, is only a float charger. It should provide most of the benefits of the Battery Tender if the battery is fully charged, but it may take a very long time to reach full charge if it is not fully charged. Also, some of the reviewers claim poor voltage control by the unit. Might be a quality control issue that affects a small percentage of them.

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Watty
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Re: Car Battery

Post by Watty » Tue Jan 08, 2019 11:44 pm

Namashkar wrote:
Tue Jan 08, 2019 5:00 pm
I am planning to be away for a few months while my car is not going to be used.
If you will be gone for more than about three months you should also research what to do about;

1) The tires can develop flat spots that will not go away after the car is driven for a while.

2) The gasoline in the car can go bad and gum up the engine.

Smoke
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Re: Car Battery

Post by Smoke » Wed Jan 09, 2019 12:30 am

iamlucky13 wrote:
Tue Jan 08, 2019 11:27 pm
brianH wrote:
Tue Jan 08, 2019 5:20 pm
neilpilot wrote:
Tue Jan 08, 2019 5:13 pm
Actually you are best served by connecting the trickle charger while the battery remains connected and in the car. Not only is this easier, but car's systems (primarily your radio) will retain their memory while the battery is maintained at a suitable charge.
Is that a good idea with modern, sophisticated battery 'tenders' that do more than just provide a constant current? I always assumed that the 'vampire' loads of the misc electronics would interfere with the tender's sensing logic.
Their logic is actually not terribly complicated. They basically check the battery voltage. Full featured models like the Battery Tenders will maintain a fixed charge rate when the voltage is below a certain level in order to speed the charging. When it hits a certain voltage, they maintain that voltage to top off the battery. While that is going on, the current the battery draws slowly declines. When the current drops to a set level, they then either switch off until the voltage drops below a threshold for topping again, or they drop to a float voltage.

The Battery Tender Jr does the latter, practically speaking, although when I measured mine I noticed it actually pulses on and off at a regular interval at float voltage. I'm not sure why they do that - if it has benefits for sulfation prevention, simplified the circuit design, or something else.

The Harbor Freight model someone linked above, according to the manual, is only a float charger. It should provide most of the benefits of the Battery Tender if the battery is fully charged, but it may take a very long time to reach full charge if it is not fully charged. Also, some of the reviewers claim poor voltage control by the unit. Might be a quality control issue that affects a small percentage of them.
I completely agree, it is not meant to "charge" a battery. I do not believe the op was asking about charging though.

brianH
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Re: Car Battery

Post by brianH » Wed Jan 09, 2019 9:32 am

iamlucky13 wrote:
Tue Jan 08, 2019 11:27 pm
The Battery Tender Jr does the latter, practically speaking, although when I measured mine I noticed it actually pulses on and off at a regular interval at float voltage. I'm not sure why they do that - if it has benefits for sulfation prevention, simplified the circuit design, or something else.
Thanks. I found a patent for one of those battery chargers:
charging circuit has a high frequency section (a bistable multi-vibrator, relaxation blocking bistable multi-vibrator or an oscillator inverter circuit) solar powered and output coupled by a close coupled RF transformer to the battery connected output section. The transformer has a secondary winding producing a current-voltage full wave output sharply defined through a two diode rectifying circuit to a multi-frequency 10 KHz to 100 KHz pulse output. The sharp pulses develops RF outputs that are in the 2-10 megahertz frequency range with specific frequencies equal to natural resonant frequencies of the specific electrolyts used in respective batteries. The resulting high frequency output that is enveloped in each pulse structure, is capable of reclaiming, maintaining and charging batteries that possess a liquid electrolyte or jell electrolyte and the output is beneficial to dry cell cell batteries as well.
It's probably a bunch of woowoo, but there's clearly more going on with some of those chargers than a simple voltage/current monitoring. It probably doesn't matter much, and I've never had any sulfation issues with my very basic charger.

neilpilot
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Re: Car Battery

Post by neilpilot » Wed Jan 09, 2019 9:44 am

brianH wrote:
Wed Jan 09, 2019 9:32 am

It's probably a bunch of woowoo, but there's clearly more going on with some of those chargers than a simple voltage/current monitoring. It probably doesn't matter much, and I've never had any sulfation issues with my very basic charger.
Sulfation doesn't occur during charging. It occurs when a battery is allowed to remain in a very low charge or discharged state for an extended period.

Some chargers are designed to pulse a recovery charge, and that pulsed charge may succeed to reversing sulfation by returning the lead sulfate crystals into the acid solution. A simply charger will typically not accomplish that reversal.

Luke Duke
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Re: Car Battery

Post by Luke Duke » Wed Jan 09, 2019 9:56 am

killjoy2012 wrote:
Tue Jan 08, 2019 5:56 pm
Just buy a battery tender, hook it up and be done. No need to disconnect the battery from the vehicle.
This. There are a lot of people in this thread that are overthinking this situation. Your fuel isn't going to go bad, you are highly unlikely to develop flat spots, your battery isn't going to explode unless you do something stupid, etc.

brianH
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Re: Car Battery

Post by brianH » Wed Jan 09, 2019 10:04 am

neilpilot wrote:
Wed Jan 09, 2019 9:44 am
Sulfation doesn't occur during charging. It occurs when a battery is allowed to remain in a very low charge or discharged state for an extended period.

Some chargers are designed to pulse a recovery charge, and that pulsed charge may succeed to reversing sulfation by returning the lead sulfate crystals into the acid solution. A simply charger will typically not accomplish that reversal.
I never claimed that sulfation happened during charging, just that my basic charger without 'pulsing technology' and its claimed restorative powers never seemed to affect my battery life.

According to this site: https://batteryuniversity.com/learn/art ... prevent_it The pulsing approach is nonsense anyway, and probably does more harm than good.

sport
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Re: Car Battery

Post by sport » Wed Jan 09, 2019 10:08 am

Luke Duke wrote:
Wed Jan 09, 2019 9:56 am
your battery isn't going to explode unless you do something stupid, etc.
It's actually pretty easy to cause a battery to explode. If you know what you are doing, it is easy to prevent this. Most people don't know what they are doing when it comes to auto batteries. They don't teach this in schools, and batteries do not come with installation and care instructions.

neilpilot
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Re: Car Battery

Post by neilpilot » Wed Jan 09, 2019 10:26 am

brianH wrote:
Wed Jan 09, 2019 10:04 am
neilpilot wrote:
Wed Jan 09, 2019 9:44 am
Sulfation doesn't occur during charging. It occurs when a battery is allowed to remain in a very low charge or discharged state for an extended period.

Some chargers are designed to pulse a recovery charge, and that pulsed charge may succeed to reversing sulfation by returning the lead sulfate crystals into the acid solution. A simply charger will typically not accomplish that reversal.
I never claimed that sulfation happened during charging, just that my basic charger without 'pulsing technology' and its claimed restorative powers never seemed to affect my battery life.

According to this site: https://batteryuniversity.com/learn/art ... prevent_it The pulsing approach is nonsense anyway, and probably does more harm than good.
Well your statement " I've never had any sulfation issues with my very basic charger" caused my confusion.

Years ago I was able to bring back a sulfated 12v aircraft battery using a pulse charger. Previous attempts to charge using a simple battery charger were futile. I could see the sulfation on the plates before and after treatment. So my experience must have been nonsensical as well.

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jharkin
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Re: Car Battery

Post by jharkin » Wed Jan 09, 2019 11:53 am

neilpilot wrote:
Wed Jan 09, 2019 9:44 am
brianH wrote:
Wed Jan 09, 2019 9:32 am

It's probably a bunch of woowoo, but there's clearly more going on with some of those chargers than a simple voltage/current monitoring. It probably doesn't matter much, and I've never had any sulfation issues with my very basic charger.
Sulfation doesn't occur during charging. It occurs when a battery is allowed to remain in a very low charge or discharged state for an extended period.

Some chargers are designed to pulse a recovery charge, and that pulsed charge may succeed to reversing sulfation by returning the lead sulfate crystals into the acid solution. A simply charger will typically not accomplish that reversal.

+1 to what nepilot said.

You want a "smart" battery tender that maintains the battery on a float charge. This means holding the battery as a specific voltage (typically 13.1v for a maintenance free sealed lead acid starting battery) and just lets the battery draw whatever current is needed to remain at that voltage.

The old "trickle" chargers are bad as they can overcharge over time and cause the battery to gas.
Leaving the battery to discharge is bad as mentioned because it will Sulfate and can freeze.
Note that this advice is the OPPOSITE of whats given for storing lithium ion batteries. DO NOT ever treat a lead acid like a lithium ion.

Battery tender is the brand most often mentioned as they are easy to find anywhere, but their units are just dumb trickle chargers IIRC. Be careful if you get one with too high a rating you can overcharge your battery. NOCO Genius is a better option as their maintainers are smart and will not overcharge, but they dont do a true float. From what I have read CTEK is even better and has a real float charge mode.


If you want to learn more, rather than trusting a bunch of strangers on the internet read:
http://www.batteryfaq.org/
Charging - http://jgdarden.com/batteryfaq/carfaq9.htm
Lifespan - http://jgdarden.com/batteryfaq/carfaq11.htm
(these articles are considered the authoritative online source for lead acid battery info, and are all based on battery manufacturer data)

btenny
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Re: Car Battery

Post by btenny » Wed Jan 09, 2019 12:18 pm

Be aware that many Mercedes cars and SUVs have two batteries. One up front and one in the trunk or other place. Is these cars working on the battery is more difficult and should be left to your mechanic. See below.

http://bestride.com/research/car-doctor ... -batteries

And for those of you battery tender fans beware that leaving a electrical device running unattended on a lead acid battery that out-gasses hydrogen is just dangerous. The thing can cause all kinds of bad things to happen. It is just easier and safer to unhook the battery if you are only going to be gone for a few weeks.

And yes unhooking the negative terminal first is best.

Good Luck.

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wander
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Re: Car Battery

Post by wander » Wed Jan 09, 2019 12:33 pm

Namashkar wrote:
Tue Jan 08, 2019 5:00 pm
I am not good at auto things, would I just uncable one terminal and if so which one (+ or -)?
That’s fine. Just remove the cable connecting to the negative battery post should do it. You will lose clock time, counter, radio stations... but it is no big deal.

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tyrion
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Re: Car Battery

Post by tyrion » Wed Jan 09, 2019 1:00 pm

Have you considered having a family member or trusted friend drive the car a few miles every 2-3 weeks to keep everything in working order?

That would charge the battery, 'rotate' the tires, mix the gasoline in the tank, circulate the oil, etc.

I read in another thread about owning two homes that someone paid a service to come in every 2 weeks to flush all the toilets, run the dishwasher, drive the car around the block a few times, that kind of thing.

bcowan12
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Re: Car Battery

Post by bcowan12 » Wed Jan 09, 2019 1:15 pm

My dad is a snowbird, and leaves a car in his driveway in Tucson for 8-9 months without issue. He removes the positive battery lead, and adds stabilizer to the gas tank before he leaves. He's been doing this for decades, and finds that the battery has no problems starting his car when he returns. (Much to my surprise -- his batteries go more years before needing replacement than mine.)

Bruce

RickBoglehead
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Re: Car Battery

Post by RickBoglehead » Wed Jan 09, 2019 1:18 pm

tyrion wrote:
Wed Jan 09, 2019 1:00 pm
Have you considered having a family member or trusted friend drive the car a few miles every 2-3 weeks to keep everything in working order?

That would charge the battery, 'rotate' the tires, mix the gasoline in the tank, circulate the oil, etc.

I read in another thread about owning two homes that someone paid a service to come in every 2 weeks to flush all the toilets, run the dishwasher, drive the car around the block a few times, that kind of thing.
Actually, with many vehicles, unless it's a substantial drive it won't charge the battery, but actually weaken it.

For example, a Ford F-150 takes a good 1/2 hr of consistent driving to charge the battery back up. Short drives, like running errands (10 minutes drive, stop, go in store, 10 more minutes, go in 2nd store) actually deplete the battery.

neilpilot
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Re: Car Battery

Post by neilpilot » Wed Jan 09, 2019 1:23 pm

RickBoglehead wrote:
Wed Jan 09, 2019 1:18 pm
tyrion wrote:
Wed Jan 09, 2019 1:00 pm
Have you considered having a family member or trusted friend drive the car a few miles every 2-3 weeks to keep everything in working order?

That would charge the battery, 'rotate' the tires, mix the gasoline in the tank, circulate the oil, etc.

I read in another thread about owning two homes that someone paid a service to come in every 2 weeks to flush all the toilets, run the dishwasher, drive the car around the block a few times, that kind of thing.
Actually, with many vehicles, unless it's a substantial drive it won't charge the battery, but actually weaken it.

For example, a Ford F-150 takes a good 1/2 hr of consistent driving to charge the battery back up. Short drives, like running errands (10 minutes drive, stop, go in store, 10 more minutes, go in 2nd store) actually deplete the battery.
Also, a series of short drives over several months without an extended drive will promote corrosion in the engine's overhead compartments. Water is generated as a byproduct of combustion, and you need to get the engine up to operating temperature and then drive at that temperature for a while.
Otherwise the moisture will condense in the overhead valve train and promote excessive corrosion.

sport
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Re: Car Battery

Post by sport » Wed Jan 09, 2019 3:36 pm

bcowan12 wrote:
Wed Jan 09, 2019 1:15 pm
My dad is a snowbird, and leaves a car in his driveway in Tucson for 8-9 months without issue. He removes the positive battery lead, and adds stabilizer to the gas tank before he leaves. He's been doing this for decades, and finds that the battery has no problems starting his car when he returns. (Much to my surprise -- his batteries go more years before needing replacement than mine.)

Bruce
Bruce,
If you want your dad to stay safe, suggest he disconnect the negative cable instead of the positive. Either way will do what he wants. However, it is much safer to disconnect the negative cable. The reason for this is that while disconnecting the positive cable, if his tool touches any metal part of the car and the cable at the same time, he will create a short circuit, with lots of sparks, molten metal, and possibly a battery explosion. The negative is already connected to the car frame, so having a tool touch both is a non-event. The same logic applies to reconnecting the battery cable(s).

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Sandtrap
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Re: Car Battery

Post by Sandtrap » Wed Jan 09, 2019 3:44 pm

Battery Minder and desulfate/
Have been using many of these for decades.
https://smile.amazon.com/dp/B005EKY20K/ref=dp_prsubs_1

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bottlecap
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Re: Car Battery

Post by bottlecap » Wed Jan 09, 2019 4:47 pm

Luke Duke wrote:
Wed Jan 09, 2019 9:56 am
killjoy2012 wrote:
Tue Jan 08, 2019 5:56 pm
Just buy a battery tender, hook it up and be done. No need to disconnect the battery from the vehicle.
This. There are a lot of people in this thread that are overthinking this situation. Your fuel isn't going to go bad, you are highly unlikely to develop flat spots, your battery isn't going to explode unless you do something stupid, etc.
I also agree with the battery tender. They are small, cost like $20, plug into the cigarette lighter even, and work. I currently use one periodically.

You can even get one that will tend and, if needed, charge.

JT

iamlucky13
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Location: Western Washington

Re: Car Battery

Post by iamlucky13 » Wed Jan 09, 2019 7:15 pm

jharkin wrote:
Wed Jan 09, 2019 11:53 am
Battery tender is the brand most often mentioned as they are easy to find anywhere, but their units are just dumb trickle chargers IIRC. Be careful if you get one with too high a rating you can overcharge your battery. NOCO Genius is a better option as their maintainers are smart and will not overcharge, but they dont do a true float. From what I have read CTEK is even better and has a real float charge mode.
I'm not familiar with NOCO, but I recognize CTEK as a reputable charger brand.

Deltran is also pretty well-regarded, as far as I know, and their Battery Tender brand actually are maintainers, not dumb trickle chargers. They run a standard constant current (bulk) phase, constant voltage topping (absorption) phase, and also a reduced constant voltage (float) phase.

It looks like a nice feature of the NOCO Genius is that many of their models include 6V compatibility. By referring to them as not true float chargers, I assume you mean they actually do a periodic topoff, rather than maintain a constant float voltage?

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Namashkar
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Re: Car Battery

Post by Namashkar » Wed Jan 09, 2019 9:23 pm

Thank you all for your valuable suggestions. I bought a Battery Tender from Costco and will give it a try. :happy

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willthrill81
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Re: Car Battery

Post by willthrill81 » Wed Jan 09, 2019 11:35 pm

sport wrote:
Wed Jan 09, 2019 10:08 am
Luke Duke wrote:
Wed Jan 09, 2019 9:56 am
your battery isn't going to explode unless you do something stupid, etc.
It's actually pretty easy to cause a battery to explode.
If it were that easy, there'd be a lot more batteries exploding considering the millions of vehicles on the road. Battery explosions are statistically rare. If they aren't overcharged, you're careful to avoid sparks, it's almost impossible for them to occur. But eye protection and gloves are a good idea when handling a battery.
“It's a dangerous business, Frodo, going out your door. You step onto the road, and if you don't keep your feet, there's no knowing where you might be swept off to.” J.R.R. Tolkien,The Lord of the Rings

bcowan12
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Re: Car Battery

Post by bcowan12 » Thu Jan 10, 2019 3:30 pm

sport wrote:
Wed Jan 09, 2019 3:36 pm
Bruce,
If you want your dad to stay safe, suggest he disconnect the negative cable instead of the positive. Either way will do what he wants. However, it is much safer to disconnect the negative cable. The reason for this is that while disconnecting the positive cable, if his tool touches any metal part of the car and the cable at the same time, he will create a short circuit, with lots of sparks, molten metal, and possibly a battery explosion. The negative is already connected to the car frame, so having a tool touch both is a non-event. The same logic applies to reconnecting the battery cable(s).
Thanks, Sport. Oddly enough, just yesterday my dad arrived back in Tucson for the first time in almost 2 years, and I was helping him get everything set back up again. He actually did have the positive cable removed, so I had it wrong. And, amazingly, that car started right back up again after sitting idle for 20 months. The battery is now 7 years old, so we're going to head to Costco to get a new one before this one leaves him stranded somewhere. Fingers crossed that the new one lasts as long as the old one :)

Bruce

sport
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Re: Car Battery

Post by sport » Thu Jan 10, 2019 7:54 pm

willthrill81 wrote:
Wed Jan 09, 2019 11:35 pm
Battery explosions are statistically rare. If...you're careful to avoid sparks,...
That can be a big "if".

Wakefield1
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Re: Car Battery

Post by Wakefield1 » Fri Jan 11, 2019 12:46 am

Cracked strap (connection between cells) inside the battery could cause a spark.

3504PIR
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Re: Car Battery

Post by 3504PIR » Fri Jan 11, 2019 11:07 pm

neilpilot wrote:
Tue Jan 08, 2019 5:13 pm
brianH wrote:
Tue Jan 08, 2019 5:10 pm
Your best bet is to remove both battery connection terminals and get a 'trickle charger' that you then connect to the battery. This will very slowly replenish the charge as it sits. Many auto stores or Amazon have choices that should run you about $20.
Actually you are best served by connecting the trickle charger while the battery remains connected and in the car. Not only is this easier, but car's systems (primarily your radio) will retain their memory while the battery is maintained at a suitable charge.
+1 unless your car is a 1972 year model. Don’t disconnect the battery.

Chances are, you won’t have an issue unless you have an older battery. You could park the car in a way that, just in case, it is in a position to make it easier to jump.

Carl53
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Re: Car Battery

Post by Carl53 » Sat Jan 12, 2019 4:23 am

For those with battery tenders, if the power goes out briefly do they automatically restart without manual intervention?

neilpilot
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Location: Memphis area

Re: Car Battery

Post by neilpilot » Sat Jan 12, 2019 6:18 am

Carl53 wrote:
Sat Jan 12, 2019 4:23 am
For those with battery tenders, if the power goes out briefly do they automatically restart without manual intervention?
Certainly

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GMCZ71
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Re: Car Battery

Post by GMCZ71 » Sat Jan 12, 2019 9:06 am

willthrill81 wrote:
Wed Jan 09, 2019 11:35 pm
sport wrote:
Wed Jan 09, 2019 10:08 am
Luke Duke wrote:
Wed Jan 09, 2019 9:56 am
your battery isn't going to explode unless you do something stupid, etc.
It's actually pretty easy to cause a battery to explode.
If it were that easy, there'd be a lot more batteries exploding considering the millions of vehicles on the road. Battery explosions are statistically rare. If they aren't overcharged, you're careful to avoid sparks, it's almost impossible for them to occur. But eye protection and gloves are a good idea when handling a battery.
Your stats are so true, but! Millions never touch the battery, its the few that disconnect the battery or add a charger or jump start that may explode. The OP's chances are higher then the millions.
John

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whodidntante
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Re: Car Battery

Post by whodidntante » Sat Jan 12, 2019 9:09 am

In my area it is possible to store a car. They will keep the battery charged and move the car now and then.

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