Forum Discussion

garmp's avatar
garmp
Explorer II
Sep 11, 2022

AGM batteries & solar battery tender

Thinking about switching over to AGM batteries & know nothing about what I should know & do. I tried to do online research but have a hard time distinguishing between a sales pitch & an honest review/opinion as I know nothing about the subject.
I did find that one important point is to keep the batteries charged while in storage. As I generally put it in storage from Nov to April. Cannot keep on our property due to our beloved HOA, so it is offsite with no electric available. Which brings me to a solar battery tender. These are effective??? Spending this kind of money on batteries, don't want them going south the first year. Since our coach is offsite can I use a solar tender discretely with no holes drilled, etc. I'd like to place the solar panel in the cab windshield & run the cables to the batteries. Does this even sound feasible?
And I guess solar battery tenders, like the batteries themselves, vary in price from one end of the spectrum to the other. And the higher the price isn't always the better.
Oh, where to start? Then there is always the consideration of total cost and what I can afford. But naturally I want the best for the least cost.
Any thoughts?
  • You could charge them up and disconnect and they'd be fine. AGMs hold a charge a long time. And by disconnect I mean pulling a cable.
  • When I had wet batteries I used a 30 watt solar panel and a weather resistant controller from WindyNation to maintain my batteries when not camping since my TT is covered. Worked very well. Are you considering Lithium batteries? If there is no draw their charge will last months. In fact many advise storing at less than full charge. The “buzz” is Lithium and not many are writing anything about other battery types.
  • We have one AGM battery being maintained by a Coleman 6 watt battery maintainer. You didn't state how many batteries you will be maintaining but Coleman also makes a 10 watt maintainer for $50. Most maintainers have a diode to keep the reverse flow of power during periods of darkness. If you totally disconnect your batteries the 10 watt may carry two. We bought ours at tractor supply. Notice a charger and maintainer are two different animals.