Battery Tender/Trickle Charger

**KChalfant** · 03-14-2023, 08:37 AM

Originally Posted by geotex1

If you do this, you simply shut all circuits down (turn breakers off and pull selective fuses) and leave only the appropriate circuit on. I have not investigated them all, but several 12VDC refrigerators are not for freezing weather. Seems peculiar considering the application, but it's right there in the owners manual.

Thank you!

**sande005** · 03-14-2023, 08:38 AM

I tend to rant on this subject.
Especially if in cold/very cold climates, there is no need for any of this for lead-acid batteries.
Make sure they are topped off with water.
Fully charge.
Fully disconnect (do not trust the switch!).
Forget until spring.

Batteries do self discharge, but the colder the slower. Over 20 yrs in Minn., with 7 batteries, they never come out of storage at less than 90% charge.
Fully charged batteries do not freeze until they reach -74F. If they do, it was because they did not hold a charge and were bad anyway.

Very hot conditions is the opposite - self discharge can be much faster, so indoors may then be advised.

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**KChalfant** · 03-14-2023, 08:38 AM

Originally Posted by Hoopy Frood

With the newer trailer, overcharging the batteries shouldn't be an issue. Some of the older WFCO converters were bad about not going to "float" mode and could indeed overcharge the batteries. Newer converters, not so much. Your refrigerator shouldn't be damaged by keeping it running. Especially if it's a 12V or residential fridge.

Thank you!

**sande005** · 03-14-2023, 08:41 AM

FYI - storage (not charging or use) advice is all over, depending on brand, for lithiums. Most say DO take indoors, store at 50% charge, and top off every few months. One brand (Victron), says they can be stored as cold as -40F. But most say at room temp.

**trailrydr** · 03-14-2023, 08:43 AM

Our storage facility only has 120v service available to its renters. We hookup a 50' UL certified extension cord (which we have snaked above the coroplast) to a battery tender in our front storage compartment of our 5er.

We disconnect the battery wires and hookup only the tender wires during the winter storage months. In the other months which we could tow, we leave all wires connected including the tender wires and hookup the tender wires (with a quick disconnect) when stored. Keeps our battery topped of year round and extends the life as well.

Other than extension, we do this with all our vehicles and get 2 1/2 times the normal battery life on all our 4whlrs, mower, boats, and autos.

**Hoopy Frood** · 03-14-2023, 09:04 AM

Originally Posted by geotex1

If you do this, you simply shut all circuits down (turn breakers off and pull selective fuses) and leave only the appropriate circuit on. I have not investigated them all, but several 12VDC refrigerators are not for freezing weather. Seems peculiar considering the application, but it's right there in the owners manual.

I didn't know that about the 12V fridges, learn something new every day. I wonder what the reasons are.

**dryfly** · 03-14-2023, 09:41 AM

One advantage to using one of the better trickle chargers or the newer converters i.e Progressive Dynamics is they routinely have a cycle that will provide desulfation, to prevent the process of building up lead sulfate crystals inside a lead-acid battery. Full battery capacity will be preserved over a longer life span of the battery.

Maybe the newer WFCO converters have this feature, but in the past they were hard on my batteries.

**Tom Traveler** · 03-14-2023, 10:08 AM

Originally Posted by sande005

I tend to rant on this subject.
Especially if in cold/very cold climates, there is no need for any of this for lead-acid batteries.
Make sure they are topped off with water.
Fully charge.
Fully disconnect (do not trust the switch!).
Forget until spring.

I”ll second Sande005 on this. I’m surprised there is still so much bad information about this around. A charged lead-acid battery, disconnected from any load, will not discharge, will not freeze, and does not need a trickle charger. During 18 years on a farm in North Dakota winters, we never had a single battery freeze or go bad over the winter even with sustained nights at -30° F. Charge them up, disconnect them (at the terminal), and “Forget until spring”. If they go bad, they WERE bad and you needed a new battery anyway. Theft is a different issue.

**trailrydr** · 03-14-2023, 10:57 AM

Here in MO have had batteries go bad in short periods of time from not being used. We do get 90+ degree days and before puting on tenders was experiencing 4-5yr car, 2yr mower, 3-4yr boat battery life. Now after using tenders, have doubled it plus and made up the money on the tenders to boot while leaving the batteries in place, hooked up and ready to go when I need to use the vehicles.

Would rather connect the tender and let it monitor the charge. Just my time, money, own experience, and opinion.

**livinthelife** · 03-14-2023, 11:07 AM

Originally Posted by Bungy

As has been stated repeatedly on this and other forums is that fully charged batteries WILL NOT freeze.

OK, not "freeze" but they can get too cold.

“A 100% fully charged battery will not freeze until approximately -76 degrees Fahrenheit,” Kimbrough, technical services manager for Interstate Batteries said in a telephone interview. “A fully discharged battery can freeze at or around 32 degrees.”