Discussion > Our Solar Charger
I don't seem to have a log-in on the forum anymore over at RP, so if you want to post this over there Brad feel free...
Our charger is built from 2 93116 SOLAR CHARGERs from American science & surplus (sciplus.com) They also have a model 94105 7 AMP SOLAR CHARGE CONTROLLER that I should probably put on the output between the solar panels and the batteries. The panels we got had a rudimentary charger circuit on each one so I just used that.
The way you use the system is also important. We charge the batteries all month, disconnect them from the charger, use them in a relatively low current application, then put them back on the charger. If you were going to put the batteries under load without removing them from the charger/controller combination, then you'd need to size the batteries to the load so that you had enough current capacity from the batteries, through the controller, to the load. The charger will try to charge once the load drops below the capacity from the solar cells. IE, if the load is drawing more than the solar cells are producing then there will be no charging going on. Once the load is removed there is surplus current available from the cells so it gets switched back over to charging the batteries.
I think if I had to redo it today then I'd use a better solar cell and a controller. It wouldn't be but about 150.00 to do it from scratch but what we have works, so until it breaks we don't need to spend $$ on it. All the parts are available from American Science or from All Electronics Corp. (allelectronics.com)
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Doc - can you post some plans or details on Rocketry Planet explaining how you built our Solar Charger?
http://www.rocketryplanet.com/forums/showthread.php?p=173218#post173218
Anyone else with ideas or contribution that might help please feel free as well.