Solar panel sizing

[captainVT]

Will be using Minn Kota Endura 30 electric motor on dingy. What size solar panel would be sufficient to charge 12V Interstate Marine 24M. Would a low cost trickle charge been sufficient? Anticipated use will be limited to shore to mooring travel. Battery housed in case w/meter. Assume I would also need charge control to avoid over charging.

[camaraderie]

You have about an 80 amp hour battery. This means you can use 40ah's before recharging. What you don't say is how many amps your motor draws...how long you use it for...and how long the panel will have to recharge your battery between use.

Let's say we find that you use ALL 40 amphours each weekend and have 5 days to put the amp hours back in. You would need a panel that could supply 8 amp hours ON AVERAGE each day. Using the 4X rule...that would mean you would need a 32 watt panel. Assuming some rainy days would suggest a 40watt panel might be a good size.
On the other hand...if you only use 5ah's a weekend...you just need something that can put in 1amphour a day...a 5-10 watt panel and no regulator needed.
Put an amp meter on your motor to understand power use if the manual doesn't state it. Then figure how LONG you use it and you will have the amphours you need to replace.


And yes...you do need to get a cheap regulator to be safe with larger size size panel with peak voltage over 15V.

[captainVT]

1:1 ratio on ah's to thrust. So I assume 30ah, lets say conservatively 15min day, max, unless cruising around anchorage, so 7+/- daily usage. So, yes 5-10 trickle charge panel should suffice once full charge is done. Plus, I would not anticipate more than 4 consecutive days of use.

Thanks. Do you have a particular brand in mind?