Proper Solar Voltage

[xymotic]

Hi all.

I've been chewing up zincs lately, so I thought I'd try unplugging the boat from shorepower for a bit until I can redo the wiring.

Anyway, I installed a solar battery 'maintainer' similar to this one.
SUNFORCE 5 Watt Solar Battery Trickle Charger at West Marine

THe panel is wired to a fuse, has I think a couple of diodes inline and is made to wire straight to the battery. However, in bright light it puts out 21v, which concerns me greatly. don't I run the risk of cooking the batteries at that voltage? These panels don't seem to require a controller, but would one work or is the panel too gutless to even try?

I just want to get by til summer when I can do a proper solar install, and want to spend the least money possible. (so no new batteries would be good

[goboatingnow]

at 5W and connected to a reasonable battery bank, teh battery determines the voltage. That 21v is only the open circuit voltage. Its be fine.

[Kettlewell]

I left one of those hooked up straight into my system when I left the boat in Florida for awhile (plenty of sun) and it was fine. You don't need a controller unless you're attaching it to a pretty small battery.