What Size Solar Battery Maintener

[minuteman62-64]

My battery is the smallest marine starting battery that Walmart had at the time (24MS-6, 625 Amps). I'm thinking of getting one of those solar battery maintainers (already figured out from other posts that it won't be a charger).

I use my boat about once/month on a year round basis. Just want to keep the battery charge up, to (hopefully) get max life from it.

The reasonably priced (for me) solar maintainers/trickle chargers seem to be in the 1-5 amp range. With my operating conditions, does it matter which amp capacity I'd use?

 

[KD4UPL]

Re: What Size Solar Battery Maintener

I'm guessing you mean 1 - 5 watts. Bigger would be better. 5 watts won't be too big by any stretch.

 

[UncleWillie]

Re: What Size Solar Battery Maintener

Just to get a sense of the requirements...
I have a 3 AMP, line powered, Smart Battery Maintainer.
It cycles for about one second every two minutes.
That amounts to 12 minutes a day at 3 amps or 36 amp-minutes.
At 12 volts that would be 432 Watt minutes per day.

Solar panels are rated for peak output under dark blue, haze free, cloudless skies and actively tracking the Sun
A 5 watt panel would need about 90 minutes a day of full noon day Sun to be equivalent. Or realistically, 4-5 hours of cloudless skies.
Unless you live in the Desert SouthWest you could not count on that much Sun on a daily basis.

A 10-20 watt (1-2 Amp) panel would be more reasonable.

 

[minuteman62-64]

Re: What Size Solar Battery Maintener

Unless you live in the Desert SouthWest you could not count on that much Sun on a daily basis.

I kinda do - just one micro-climate West of the inland valleys of San Diego County. Nevertheless, I get it - bigger is better.

 

[Star]

Re: What Size Solar Battery Maintener

Don't even waste your time. The cost is high and solar cells and salt air don't hold up well. How frequently do you go out and what is the average hours of a trip? Put the battery in with Anderson connectors and take it home with you when you aren't using the boat. A 303 battery isn't that hard to handle!!!

 

[MH Hawker]

Re: What Size Solar Battery Maintener

I have been using a 15 watt and regulator with good results this summer. It has kept mine topped off.

 

[minuteman62-64]

Re: What Size Solar Battery Maintener

Don't even waste your time. The cost is high and solar cells and salt air don't hold up well. How frequently do you go out and what is the average hours of a trip? Put the battery in with Anderson connectors and take it home with you when you aren't using the boat. A 303 battery isn't that hard to handle!!!

Actually, the boat is sitting on a trailer in my side yard. There is no power there and it is a minor pain to string an extension cord out there to hook up my charger.

 

[UncleWillie]

Re: What Size Solar Battery Maintener

I have a boat in the side yard also.
I have a 100 ft extension cord that runs around the side and back of the house, under the deck, and into an an outlet.
The cord has been out there for two years. It is now mostly buried under the mulch and the soil. It is just fine, and handy too!

The cord will be cheaper and more reliable than the solar panels.
The solar panels look cool and high tech on the surface.
Unless you buy high quality and high priced panels, the are going to last about as long as those solar led lights in the flower bed.

If you get more than a year out of them you'll be lucky.

Where all other options have been exhausted, Solar Panels have their place.
If there is an outlet within a half mile, you are not at that place.
Accept the "Minor Pain" now, to avoid "Reoccurring Pain" in the Future.