How to keep car battery charged when car isn't being driven

[IanB]

No, you didn't read what I wrote earlier. I won't generally be using it with a solar panel, nor is that feasible most of the time where I live.

I think I'm just confused. What is a solar generator, if it is not a solar panel?

[wilfred]

I once used an Optima red-top battery. They can (or mine did) hold a charge suitable for starting a car for quite a long time. I'm testing my memory but I think I had one sitting around 18 months and it would still start the car.

I'd also install a switch on the battery terminal to disconnect it from any residual current drain in the car whilst not in use.

Since you're up for a new battery it might be an option worth looking into.

[Nusa]

Since the problem revolves around the availability of help in your case, my suggestion would be to have the outgoing guy remove the battery from the vehicle and bring it to your home where it can be charged as required with the charger you already own. When you get someone new, have them put the battery back in the vehicle the first time they need to use it.

I'm assuming you're physically unable to get to the car on your own. If are able to, then the solution is even simpler. Run the car for 15-20 minutes every week. You don't have to drive anywhere -- just start it and let it idle long enough to charge. That should work for a long time, assuming you start with a full tank.

You might still need a new battery, of course. They don't last forever.

[Tofi]

If you have a battery kill switch then that would do. But if you want to prolong the shelf life of the battery you could keep it indoors either connected to a trickle charger or disconnected. The typical shelf life is about 3 years more or less.

[pardo-bsso]

surprised no ones though of putting some sort of connector on the front of the engine to allow you to crank the engine by hand if the batterys flat

 

I owned a car with exactly that feature (A Citroën 2CV6). I never needed to use it with a flat battery, but I tried it out one or twice to see if it worked (it did).

I had a 3CV and started it by hand just to amuse people. It surely looked strange to them.

[nctnico]

I once used an Optima red-top battery. They can (or mine did) hold a charge suitable for starting a car for quite a long time. I'm testing my memory but I think I had one sitting around 18 months and it would still start the car.

Agreed. Everything starts with having a high as possible capacity, good quality battery. Also don't forget about keeping the battery connections clean.

[Bud]

Do not disconnect the battery, this may reset the radio and require reactivation or, worse yet, deactivate the air bags. Do a research or speak with a mechanic is it safe to cut the battery power off.

Edit: See if you can get away with starting the engine and idling for 5 min in the garage once a week or so, hopefully may not be a big crime from the landlord perspective.

[Hogwild]

So, do you mean that what the marketing people call boosting is just a superfast charge?

[sokoloff]

From the battery's perspective, yes; there's no bright-line difference between a boost and a charge.

From the typical user's perspective, it's a boost of power to help them get a car started with a marginal battery.

[Hogwild]

The term solar generator is generally used for the products from
Jackery
Inergy
Bluetti

and so on. Basically a large battery that charges either via solar, 12V lighter outlet or AC (or combinations thereof).

I'm definitely capable of walking. I'm stiff as a board sometimes, but I walk.

From what I've been told, the airbags are not likely to be working on a 2000 model car anyways, unless they're replacements. Mine are originals.

I'd never heard of a battery disconnect switch. Thanks!  Should I be choosy about which one I get?

Do we all agree that Optima batteries will last longer without charging?

I read on mechanics' websites that to properly charge a battery, you have to drive at approxl. 60KM/h, so that contradicts what was said about simply running it for 5 mins. without moving.

On a separate note, my old battery is a Costco. It's lasted 7 years. Wow. Definitely got good value out of it.

[nctnico]

I read on mechanics' websites that to properly charge a battery, you have to drive at approxl. 60KM/h, so that contradicts what was said about simply running it for 5 mins. without moving.

That depends on your car. My car (Ford from 2005 IIRC) for example has a 'smart charge system' that tops up the battery quickly right after the car has started. So letting it idle for 5 minutes would charge the battery for quite a bit. From what I have read this only works well with modern calcium batteries. In my car there is an extra connector on the alternator that lets the control unit push the alternator to deliver more power for charging rather than just outputting the battery's float voltage.

[Hogwild]

Hey, how come everyone else gets all this cool technology and I didn't even know about it. 

Calcium? Sheesh, I have a lot to learn.

Does the equivalent Red Top have higher capacity? I ask because I'm wondering if it would take longer to charge as a result?
So far, I can't find one anywhere near me. And wow, prices are through the roof for batteries.
Hmmm...reading reviews on Amazon.cva, the Red Top has roughly 9% of reviews as 1 or 2 stars. When I read the review, people report the battery dying after a year or 18 months. Yes, I know that people are more likely to complain online, but still, that doesn't sound good. What makes it worse is that many of the buyers report than when they called Optima for a warranty replacement, Optima refused to replace it.

Maybe I should get my alternator checked when I go to get the battery replace. Do alternators die with age, or mostly just usage? I ask because my car only has 150,000 Km on it.

[bdunham7]

From what I've been told, the airbags are not likely to be working on a 2000 model car anyways, unless they're replacements. Mine are originals.

Complete FUD, unless they are the recalled Takata models that 'work', but then kill you.

Do we all agree that Optima batteries will last longer without charging?

AGM batteries do generally fare a bit better at partial charge levels, but are also much more prone to random sudden death. 

I read on mechanics' websites that to properly charge a battery, you have to drive at approxl. 60KM/h, so that contradicts what was said about simply running it for 5 mins. without moving.

The battery needs to be moving to get things stirred up?      The only nugget of truth behind that fable is that there are some cars where the alternator voltage at idle will be below the desired charge voltage even at low load levels.  AFAIK, that was mostly true on cars that are be quite old (>25 years) by now.  Some other cars deliberately don't fully charge the battery under some conditions to save fuel, Honda seems to be fond of this arrangement.  You can usually defeat these schemes by turning on your headlights.  Most cars will eventually fully charge their batteries at idle--but it may take several hours.

On a separate note, my old battery is a Costco. It's lasted 7 years. Wow. Definitely got good value out of it.

Unless you have a car with exceptionally high quiescent draw, I'd recommend you simply get a portable jump-pack and replace your battery more often if the need arises.  Even if it occasionally gets run down, you'll probably still get 5 years or so out of it.  I'm not sure about Canada, but here Costco/Interstate,  Walmart MAXX and a number of others are all pretty decent.  Prices are pretty high these days though...

[rcjoy]

You need a trickle charger.  Leave it plugged in at all times, and it will maintain the charge automatically.

Here is an example:

CTEK - 40-206 MXS 5.0 Fully Automatic 4.3 amp Battery Charger and Maintainer 12V

https://www.amazon.com/gp/product/B00CD44RQO/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1

[wilfred]

Hey, how come everyone else gets all this cool technology and I didn't even know about it. 

Calcium? Sheesh, I have a lot to learn.

Does the equivalent Red Top have higher capacity? I ask because I'm wondering if it would take longer to charge as a result?
So far, I can't find one anywhere near me. And wow, prices are through the roof for batteries.
Hmmm...reading reviews on Amazon.cva, the Red Top has roughly 9% of reviews as 1 or 2 stars. When I read the review, people report the battery dying after a year or 18 months. Yes, I know that people are more likely to complain online, but still, that doesn't sound good. What makes it worse is that many of the buyers report than when they called Optima for a warranty replacement, Optima refused to replace it.

Maybe I should get my alternator checked when I go to get the battery replace. Do alternators die with age, or mostly just usage? I ask because my car only has 150,000 Km on it.

I just mentioned Optima because that is the only AGM type battery I ever owned. You have to take internet reviews with a pinch-of-salt at times. Some reviews are clearly from people who are a bit distracted. You can read Optima's take on being bashed here. https://www.optimabatteries.com/experience/blog/optima-batteries-suck-the-truth/ .

Optima batteries aren't super high capacity. They have other attributes typical of AGM batteries, like better recovery from deep discharge, they self-discharge slower, they can be used in various orientations, are less susceptible to vibration damage and have better cold weather performance amongst others. But they cost more.

You may not need a cut-off switch and depending on how inconvenient pulling the battery cable is you may just as well do that. Battery cut-off switches are popular with off-roaders and campers who want to protect the engine start battery from discharge when running accessories from a second battery.

Most alternators see out the useful life of the car. It happens but it's not all that common.

People can't help overcomplicating things. Seek a simple solution.

[2N2222A]

Usually a car can be parked for 3 to 6 months before the battery drains nearly completely. With the lead calcium type marine batteries they can last a year. But these numbers are for older cars that don't power things like keyless entry and whatever else.

Just get the right kind of battery and disconnect the negative terminal if it's going to sit too long as sokoloff and others said. You can also buy one of those lithium battery jump starter things if your battery has drained too much. A solar charger will be worthless without overhead sunlight.

[andy3055]

Since OP is not allowed to hook up a trickle charger in the parking space, how about getting one of these? He can keep it topped up in his apartment and take it down to the car when it needs a jump start. They are great. Even the AAA guys carry these instead of running two cables to jump start cars.

https://www.harborfreight.com/search?q=jump%20starter%20and%20power%20pack

[sokoloff]

I doubt any solar solution will work in an indoor garage with artificial lighting. Natural solar is substantially brighter than indoor artificial lighting.

[Bicurico]

1) Modern cars may not support messing around with the battery. My BMW doesn't allow the user to change the battery. If I would do so, I would need to hook the car to the computer and use service software to activate the new battery! I guess that is not an issue for OP's current car, but he is better advised that most solutions suggested here, may not work in the future.

2) In my opinion, the best option is to just disconnect the battery after the car is parked in the garage. The car will consume battery power to keep the clock and other systems running even with the car switched off. Just disconnect the red (+) cable from the battery. This should allow the battery to keep charges for months.

3) If even longer periods are required, then it may be reasonable to take the battery out and regularily charge it in an aired environment - definitly not inside the house. For that a trickle char charger can be used. However, if the car is not moved for many months, the battery issue is just one problem! The tires will get deformed, oil impurities will cause sediment and eventually cloak tubes and random moving parts will glue themselves due to oxidation (wheels, breaks, maybe even motor components).

To maintain an unused car, it should be run every week or at least once a month.

I have been there and in the end I sold the car I inherited from my father, much to my own sadness. But I just did not have the time and resources to keep the car, which I did not use enough.

Another suggestion: depending on where OP lives, maybe renting a car for when it is needed, might be the cheaper and more reliable option? I understood that OP is not the driver, so why not have the driver come in a rented car? Sometimes the solution  might be a bit outside the box - no offense meant.

[sokoloff]

Relative to the previous advice: disconnecting the negative (black) side of the battery is safer on most cars. Reason being is that if you short the tool between the battery terminal you're working on and the chassis/ground of the car, nothing happens if it's the same terminal that's already connected to the ground. If you are disconnecting the positive terminal first and touch the wrench/ratchet between the terminal and the chassis, you are creating a direct short between the battery terminal you're working on and the chassis that is electrically connected to the other terminal. (There are extremely few, typically quite old [often 6 Volt], cars that are positive-ground. OP's car is surely negative-ground.)

[coromonadalix]

1) Modern cars may not support messing around with the battery. My BMW doesn't allow the user to change the battery. If I would do so, I would need to hook the car to the computer and use service software to activate the new battery! I guess that is not an issue for OP's current car, but he is better advised that most solutions suggested here, may not work in the future.

2) In my opinion, the best option is to just disconnect the battery after the car is parked in the garage. The car will consume battery power to keep the clock and other systems running even with the car switched off. Just disconnect the red (+) cable from the battery. This should allow the battery to keep charges for months.

3) If even longer periods are required, then it may be reasonable to take the battery out and regularily charge it in an aired environment - definitly not inside the house. For that a trickle char charger can be used. However, if the car is not moved for many months, the battery issue is just one problem! The tires will get deformed, oil impurities will cause sediment and eventually cloak tubes and random moving parts will glue themselves due to oxidation (wheels, breaks, maybe even motor components).

To maintain an unused car, it should be run every week or at least once a month.

I have been there and in the end I sold the car I inherited from my father, much to my own sadness. But I just did not have the time and resources to keep the car, which I did not use enough.

Another suggestion: depending on where OP lives, maybe renting a car for when it is needed, might be the cheaper and more reliable option? I understood that OP is not the driver, so why not have the driver come in a rented car? Sometimes the solution  might be a bit outside the box - no offense meant.

For  short periods  you have some solar panels with OBD connectors, it will charge and maintain the battery,   and yes for all mentioned possible problems over a very long storage time,    put the car on blocks to avoid tires deformation, and add fuel stabilizer  ....and the brakes  may rust a little bit

[Bicurico]

I stand corrected regarding the disconnection of the negative terminal instead of the positive one.

[Circlotron]

surprised no ones though of putting some sort of connector on the front of the engine to allow you to crank the engine by hand if the batterys flat

The ECUs on some cars are set to allow the engine to crank over several rotations before the fuel injection begins, especially on the first start from cold. You could never manage that by hand.

[IanB]

The ECUs on some cars are set to allow the engine to crank over several rotations before the fuel injection begins, especially on the first start from cold. You could never manage that by hand.

When you do start a car by hand it usually takes 10 or 20 turns of the handle before the engine fires...

[Bicurico]

I really meant the no offense part.

My father in law is 86 and was confronted with the fact that he is not able to drive anymore.

I keep thinking what to do with the car: it would be rational to just sell it. For the children it would be reassuring to know that he won't drive for sure.

But I do understand that in terms of self esteem it may be better for him to keep the car, even if it is just for the thought that if it was really necessary he could drive it (which he can't or at least shouldn't).

And this is the second reason why I mentality debate with myself how to keep the car in a working condition, apart my previous experience with my father's car.