Another Solar Charger setup question

[Zackdadams]

He knows batteries and electric LOL.

Drives a tesla, has an electric zero turn mower, Electric push mower, huge solar array on his house, Electric whole home air conditioning system, which I didn't even know existed!

 

[zackmorris]

Here's what my rocket scientist neighbor said:

Me: Mind if I pick your brain for a minute? A friend is putting together a solar charger on his T-top boat. He has a 36V lithium battery for his trolling motor. He thinks one 100 watt panel will provide enough to keep the battery charged in between use. Thoughts? If he provides less than 10 amp charge, can it damage the batteries?

Engineer: "I think he will fine depending on how hard and the rest time for recharge. On my 12V system, I typically use about 250W on a trip. So if he used the same, it would be 750W. His panel should output about 700W/day. That is while his is fishing too (in the sun obviously). So if it rests 2 days he'll be good."

Me: I thought I read somewhere that lithium batteries can be damaged over long term with a trickle charge?

Him:" ON trickle charging... That is correct, however, modern day BMS system prevent trickle charging. The ones I use I can set the hysterisis on how far down a cell need to discharge before letting it charge again.

BTW - using multiple batteries in a lead acid system works fine because when lead is full, it still passes current on to the next cell. When Lithium is full, it stop all current flow."

Me: He's putting together a nice Victron system.

Him:" I like Victron. What panel is he using?... (I linked it)

I used connectors from that company (Brouge) and they seem to be fine (so far). I think the dividing line is between the flexible (not having good packaging) and the rigid (better packaging, less flexibility for install). That panel looks like it rigid, so that is probably the right answer.

Me: Sounds like it has your stamp of approval, thanks

Him: Yep, looks like a good system.

Thanks for asking him. Appreciate all the input on this!