Solar Battery Charger

[Cispook]

Anyone use and been successful with a small solar battery charger for use during storage?

[Northerngirl]

Yup. 10 Watt cheap panel. Worked better than a battery tender I used previously. Even worked at times we had pretty cold weather with snow.... just needed to remember to go and clear the snow off of it from time to time.

[Cispook]

Originally Posted by Northerngirl

Yup. 10 Watt cheap panel. Worked better than a battery tender I used previously. Even worked at times we had pretty cold weather with snow.... just needed to remember to go and clear the snow off of it from time to time.

Where did you buy same?

[Mattirs]

Just be sure the batteries are fully charged before storing, because 10 watts @ 13.6 volts is barely 0.7 amps. That is not enough to charge a battery at all. You might want to go with 25 or 50 watts. This will take care of any parasitic draws and a little left to do a top off charge.

Thanks
Matti

[Northerngirl]

You are correct that one should start the storage time with fully charged battery and put the trailer in storage mode &/or put a cut off switch right at the battery to avoid parasitic draws. I do attach the small panel with a cheap controller directly to the battery.

Found the 10 watt to do just fine at keeping the battery well above the damage zone. In fact after 5 months of sitting the batteries were at 13.2 and that was even with the panel not facing to the south due to the position location of the trailer. No doubt it would have done even better had I been able to position it to capture more light than it did.

Picked up the one I am using from a place called Canadian Tire as I am in the north.

[Cispook]

Thanks to the both of you - they will be fully charged. It is a set o AGM batteries. I looked on line and found everything from cheap to wow on small solar charger for battery. I also have a battery disconnect that I throw when in storage.
Thanks again

[PatriotNM]

Is a battery disconnect necessary if you have a functioning "use/Store" switch? I have a 2018 FC with the solar package on it and this will be the first time I put it into storage for any length of time so I am curious about what I can do to protect my AGM batteries as much as possible over the winter...

[Snowy]

Originally Posted by PatriotNM

Is a battery disconnect necessary if you have a functioning "use/Store" switch? I have a 2018 FC with the solar package on it and this will be the first time I put it into storage for any length of time so I am curious about what I can do to protect my AGM batteries as much as possible over the winter...

The stock use/store does not disconnect all loads.

[uncle_bob]

Hi

Ok, here's the math:

Parasitic draw on a trailer can be anywhere between 0.1A and about 0.3A. It depends on which trailer, what era, what options, and how lucky you got. That gets you to 2.4 to 7.2 AH per day.

Battery self discharge can be as high as 15% per month. That's up around 30AH per month or one AH per day. How likely this is .... who knows.


Solar for 8 hours a day in the winter is doing pretty good. Full output for that period is doing VERY good.

10W at 13.2V through a 90% efficient converter is a bit under 0.7A. 8 hours at 0.7A would be 5.4 AH. A good guess is that you will be at <70% of that with an arbitrary location for the panel. That gets you to 3.8 AH.

So *maybe* it works, maybe it doesn't work. How lucky do you feel?

A more conservative approach would be to go with something in the > 20W range.

Bob

[jftompkins]

Am using 5W mounted on propane cover and put an On/Off switch on Propane detector for storage (OFF and undo pigtails from tanks). Also have Lifeline 6V GPL-4CT AGM so they do not degrade as much in storage....and during winter sol months will pull batteries for indoor storage....so far this works for us ...2017 FC23FB.