Solar Charger

KLC Lewis wrote:
> <Chris_MdR.TakeThisOut@gmx.net> wrote in message
> news:1175450575.993132.203150@y66g2000hsf.googlegroups.com...
>> Is there a cheap and easy solar charger available, that I can use to
>> keep the batteries full when I don't use the boat in a while? I just
>> want it to maintain the charge, so that I can be sure to return to
>> full batteries after a while of non-use, and don't have to deal with
>> shore power cable and charger. It needs to be able to sit outside, in
>> the cockpit.
>>
>> There would be no load other than keeping the batteries (two, I think
>> 54 Ah each) topped off.
>>
>> Thanks!
>>
>
> Yah, one of the little 5 amp solar trickle chargers should be able to do
> that for you. Boatus, Defender, even auto supply stores should carry them.
>
>
A 5 amp solar charger isn't little. That's about what I get from an 85
watt panel in full sun. The panel is 42" x 28.5" x 1.4" Maybe you were
thinking 5 WATTS
 >> Stay informed about: Solar Charger 

>There would be no load other than keeping the batteries (two, I think 54 Ah each) topped off.

Can someone knowledgeable estimate the float current needed to keep
these batteries at full charge??
 >> Stay informed about: Solar Charger 

On 2 Apr 2007 02:20:00 -0700, "terry@terryking.us"
<terry.DeleteThis@terryking.us> wrote:

>>There would be no load other than keeping the batteries (two, I think 54 Ah each) topped off.
>
>Can someone knowledgeable estimate the float current needed to keep
>these batteries at full charge??

The "Self Discharge" rate for lead acid batteries varies by
construction and condition but is commonly quoted at about 40% per
year which translates to 3 or 4% per month.

In other words, a 54Ah battery needs about 2Ah per month to stay fully
charged. Assuming 720 hours per month, an average trickle charge rate
of 2 / 720 amps (about 3 milliamps) per battery should do the job.
 >> Stay informed about: Solar Charger