T&T: Solar maintenance charger

[LRZeitlin at aol.com]

In a message dated 8/3/07 12:01:25 AM, Joe writes:


> I need to size the correct solar charger for my boat this winter.
> I have the following batteries  --   4 6 volt golf carts ( 400 ah )
> 1 - group 31 starting batter
> 1- group 27 starting battery.
> Was planning to last all together and then run charger into all of them
> unless
> a reason no to do that -- how may watts or millaamps do I need?
>

If it is just a question of maintaining the batteries during winter storage,
all you need to do is compensate for self discharge. This is about 2% a month,
assuming that there are no leakage paths. I estimate that you have about 600
amp/hrs of capacity so you need to supply about 12 amp/hrs per month.

A 10 watt solar cell should do the job nicely. With that much ampere hour
capacity, you do not need a controller. Connect the cell directly to the
batteries through a simple diode.

Now a real electrician can tell me I'm all wrong.

Larry Z



**************************************
 Get a sneak peek of the all-new AOL at
http://discover.aol.com/memed/aolcom30tour