Battery questions (Cold Climate)

While I try to avoid those conditions any more, for a battery in use, cold temperature increases the internal resistance and diminishes its capacity pretty fast… neither cold or heat are good for a battery both damaging in their own different ways…

It gets cold and we have harsh winter conditions here, but I leave the batteries fully charged in my vehicles but disconnected… my TT is plugged in almost all the time now…

Batteries that would provide 100 percent capacity at 80°F will typically deliver only 50 percent at 0°F... most lead batteries do not function well when the temps drop below -20*F, or below 0*F for that matter…
the discharge rates of starting batteries becomes really high at those temps… I understand you need to have your fingers crossed while turning the key to start the truck…

according to the chart I have seen, a battery freeze points depend on state of charge or discharge…
A brand new fully charged battery will not freeze unless the outside temperature hits - 77 F...
A battery that's only charged to 75% will freeze when the outside temperature reaches - 35 F...
A 50% charged battery will freeze @ -10 F and 25% charged battery will freeze @ + 5 F…

A fully charged battery in good condition with no charge and no load would be fine for a long time… but remember some batteries still in usable condition can have its own parasitic load, and might need recharged during long term storage of more than a couple of months…

BTY who uses or installs single stage converter/ chargers in a RV??? How long ago were they used???

I don’t remember ever having one that wasn’t at least a regulated two stage automatic shutoff unit...
True the regulation wasn’t always the best available…

Last winter I left the two Trojan T-105s in the TT and the converter running.

During the winter, the converter failed and the batteries ran down (propane detector, etc). The coldest it went down to was a few degrees below zero. That was enough to freeze the electrolyte and crack the cases on both batteries (since discharged batteries freeze at a lower temp than charged batteries).

If I left the batteries in the TT with the converter running again, I would leave a small light on in the TT so I could see there was 12V power just by looking out the window at night.

Steve

Hi,

Charge it fully, disconnect it. Charge again in 2 months. Repeat as necessary.

All converters are fine in cold temps. Plug it in and leave it.

I leave tractor and boat 12V batteries in the units all winter fully charged with absolutely 0 load on them. No carger running. Never had a problem and it does get very cold here in Ontario. Batteries are heavy to lug up and down ladders.

The RV batteries get to go South and stay warm and in use.

You don't say whether you have a motorhome or a trailer, or if you have a generator. Most generator manuals recommend running them monthly. It's hard to do this if you remove your battery. A good reason for keeping your battery in place and plugged in.

I always pull the battery when I finish Winterizing, keep it in my house basement shelf along with the battery I pull out of my lawn tractor... My thinking is keep them stored In a more stable temperature certainly cant hurt.

Mike

I have always left my battery in the RV and the RV plugged in. Never a problem. When I had a single stage converter I bought a Battery Minder and still use it even though I now have a 3/4 stage converter, it uses less power.

Fully charged I have taken batteries to minus 40 more than once. Your choice of C or F at that temp (it don't matter).

I'm not sure what the freezing point is but it's below -40.

Discharged.. Charge 'em.

As Harvey51 noted lead acid batteries retain a charge quite well in cold weather, assuming no load. If fully charged they will be fine, hot weather is what kills a lead acid battery. Having said that a 3 stage converter or battery maintainer isn't a bad idea. I don't use one but we do have a small solar panel on top of the AC unit that keeps the house batteries charged up.