Charging battery while in storage

[Bailey'sMom]

I am getting ready to put my TM away for the winter and am wondering how to keep the battery charged while it sits for 9 or 10 months til my next vacation.

Can I just keep the TM plugged into shore power all winter? Will that cause an problems? I could set it up to be on a timer so it only charges a couple hours a day.

I don't have a trickle charger but I could buy one. If this is the better option then how would I hook up? Direct to the batteries or to the Bargman connection?

Any suggestions welcome.

[scrubjaysnest]

There are many ways to do this.
1. Remove the battery and put it on bench. Connect a trickle charger about once a month over night. This way will be the easiest to check fluid levels.

2. If the camper is stored outside add a 5 watt solar panel. keep the snow off the panel and open the camper every couple of months to check battery fluid levels.

3. Make a pigtail to connect either a smart charger or trickle charger to the bargman. Check fluid levels every couple of months.

4. About once a month plug into shore power over night. Check fluid levels ever couple of months.

Your biggest problem is to keep the battery from freezing. Except for the possible freezing issue you could probable let the battery go two or three months before plugging into shore power over night. This maybe your simplest and cheapest route.

Overcharging(using the on board convertor) and freezing are your biggest issues

Originally Posted by Bailey'sMom

...
Can I just keep the TM plugged into shore power all winter? Will that cause an problems? I could set it up to be on a timer so it only charges a couple hours a day.
...

What Scrubjay says ...

The WFCO will overcharge at a constant 13.7V if left plugged in, evaporating battery water. But one day a month or 1 hr a day should be ok.

IIRC some other battery maintainer/chargers are more sophisticated and claim to help with battery sulphation in maintenance mode. Instead of just putting 13.7V on the battery for an hour a day, like the WFCO with a timer, they may put a higher voltage pulse (14.6V?) for a shorter time period.

It sounds like you have shore power available to the TM location based on the options you are inquiring about. I recommend adding a pigtail directly to the battery and connecting to a Battery Tender (Link Below). They can be left on indefinitely and will not over charge the battery. I do not recommend connecting the Battery Tender to the Bargman as it will have a negative effect on the sensing circuitry. I have gotten 8+ years out of motorcycle batteries using battery tenders.
http://www.amazon.com/Battery-Tender...battery+tender

[Bill]

One minor complication to in-storage charging is that the trailer has a number of phantom loads - that is, devices which use some power even when they are turned off. The drain isn't big, but it is constant, and will flatten your battery in a week. A small trickle charger may not be enough to overcome this drain, so the eaiest solution is simply to disconnect the battery from the trailer. Either disconnect the black wire on the + terminal, or remove the fuse that is in the black wire.

Bill

Bill

This is why I like the Battery Tender. It can provide up to an amp as needed based on battery voltage. The motorcycle had phantom loads (alarm etc) and as I mentioned, it allowed an 8 yr old battery start the bike.

Originally Posted by Bill

One minor complication to in-storage charging is that the trailer has a number of phantom loads - that is, devices which use some power even when they are turned off. The drain isn't big, but it is constant, and will flatten your battery in a week. A small trickle charger may not be enough to overcome this drain, so the eaiest solution is simply to disconnect the battery from the trailer. Either disconnect the black wire on the + terminal, or remove the fuse that is in the black wire.

Bill

Not sure what loads will do to other charger behaviours, so I routinely isolate the battery as you suggest before charging, trickle maintenance or otherwise.

As for the WFCO, some have suggested that it's the loads that keep the WFCO from dropping it's voltage from 13.7V to a trickle 13.2V. So I tried removing all DC fuses and occasionally checked the voltage on the battery. It did drop down to 13.4V once but all the other times it was still 13.7V.

[Bailey'sMom]

Originally Posted by rumbleweed

Bill

This is why I like the Battery Tender. It can provide up to an amp as needed based on battery voltage. The motorcycle had phantom loads (alarm etc) and as I mentioned, it allowed an 8 yr old battery start the bike.

Hi rumbleweed

Does this mean I could leave the battery in the trailer and hooked up to everything but just attach the battery tender to it? I do not look forward to trying to remove the batteries.

Sara

[Bill]

Originally Posted by Bailey'sMom

Does this mean I could leave the battery in the trailer and hooked up to everything but just attach the battery tender to it?

Sara -

Rumbleweed will chime in, and he has a good setup. Yes, you can leave the battery in the trailer with the Battery Tender attached to it. I don't think you have missed the other two important points in this discussion, but just to be sure ....

First, if the Battery Tender is trying to trickle charge at 13.2 volts and the WFCO is charging at 13.7 volts, then the WFCO will win, meaning it will take over the charging process.

Second, the WFCO will eventually overcharge your battery.

So if your question means "Can I attach the Battery Tender to the battery, and power up only the Battery Tender but not the TM during storage?", then the answer is Yes. That is a good way to proceed. And when you are camping, remove power from the Battery Tender and power up the TM. One or the other, in other words.

Didn't mean to beat a dead horse here, but batteries are expensive.

Bill

Thanks Bill. I added a pigtail directly to the battery and have access to the polarized 12V plug end when the TM is closed. ( Closing removes some of the phantom loads) Do not connect the TM to shore power. I have a small vented but rain proof box for the battery tender that sits under the TM and connects to the battery pig tail and a 110V extension. When I prepare for a trip, I disconnect the Battery Tender and connect the TM to shore power ( same extension cord) to pre-cool the fridge. The battery tender is not a constant trickle charger, but rather varies the charge with the battery condition. It has high enough current that it will replace the current used by the elect jack during positioning.