What to use Battery charger or Battery Maintainer ?

Thread Starter

250ptm

Joined Jul 29, 2010
53
Question:

My car is not used very often, maybe once or twice a month.

I have now had 3 new batteries in the past 32 months. Two of them have been replaced under the original warranty.

My battery has a constant 37mA draw from the on board electronics. It is rated at 63AH.

I have measured the daily voltage drop it is approx 0.0255v per day. It reaches 12.4 volts from a fully charged condition in approx 11 to 12 days.

I have read and been told that at voltages below 12.4 a battery may begin to sulphidate. Which leads to plate damage.

This is also what the guys in the battery shop said was my problem.

I need advice on either buying a battery charger or a battery maintainer, but cannot figure out which to use, and what I should be really be looking for. E bay is full of them. Hope someone can point me in the right direction.

.
 

Thread Starter

250ptm

Joined Jul 29, 2010
53
Thanks Eric thought about that unfortunately car is in garage, also do solar powered chargers have any overcharge features. Whatever I get needs to run 24/7 without a possibility of overheating the unit itself
 

Ian0

Joined Aug 7, 2020
9,668
Is it a wet battery or a VRLA battery?
If you keep a wet battery on float charge, check the water levels and top up regularly. Otherwise, keeping it on float-charge will eventually ruin the battery.
If you change to a VRLA battery (most cars with stop-start already have VRLA batteries), they are guaranteed to withstand permanent float-charge for 5 years (or 10 or 12 years for some of them).
For a wet battery, fully charging it once a fortnight works best.
Is it feasible to disconnect the battery, or will it forget too many settings?
 

jpanhalt

Joined Jan 18, 2008
11,087
I have several automotive batteries to worry about. When not being used regularly, I keep then charged with an inexpensive HF trickle charger. One for each battery in the Winter.

Yes, anti-theft systems, etc. in modern cars help drain and destroy a battery. One alternative is to just disconnect the negative terminal. However, doing that is not without consequences. Obviously, anti-theft measures don't work. It resets the smart systems, and for example, engine settings will go back to default. You then need to complete a "drive cycle," which can take at least 100 miles or more. In the meantime, your car will not pass an emissions inspection. Your trip meter and clock will probably be off too.
 

Thread Starter

250ptm

Joined Jul 29, 2010
53
Ian0 yes it's a VRLA. However mine does not have the warranty you speak of. also as jpanhalt points out there is the consequence of losing settings with a disconnect. Jpanhalt . What is the inexpensive HF trickle charger you are using?
 

Reloadron

Joined Jan 15, 2015
7,501
Going into the cold winter here where I live. The wife's truck and my motorcycle will remain mostly in the garage. I just use a few simple Battery Maintainers on both and during the winter start each maybe once a month. Here is an example. The units I use are in the 750 mA to 1.0 Amp versions and do fine.

Ron
 

Thread Starter

250ptm

Joined Jul 29, 2010
53
Thanks to all who have responded. I have ordered a couple of Maintainers. Will post back with my comments on them once i have used them for a couple of months.
 
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