Solar panel

[Beehpee]

Hi all, I've acquired FOC a small solar panel, it has come out of a vito van and was being used to keep the battery charged when it wasn't in use, I know next to nowt about solar panels so here go's, it has no labels on it whatsoever so no idea of make or type, I measured the voltage it was putting out and in direct sunshine it was 21.7 volts, now when it was being used on the vito it was fitted using no voltage regulator just wired straight to the battery, seems to me that it should have had a reg fitted, I'm planning to use it to keep my caravan battery topped up so I need to know if I need to buy and use a regulator, didn't bother me if it was cooking the vito battery but I don't want mine to over charge, any help much appreciated.

BP

 

[intransient1]

Hi Beephee,
yes you will need to buy a regulator it not only controls the voltage and amps that go into your battery it stops it charging when the battery is fully charged.

 

[MichaelE]

You need to find out the solar panel size ie wattage as for the low end ( around 15 watts you will not need a regulator on battery size 90 amp upwards) Anything bigger you will.
Regulators will take a % of the amps generated when fitted.

 

[Gozza]

Hook the panel to a battery that has become fairly low and measure the voltage and current - from this you can calculate the wattage (watts equals volts times amps). This will tell you the wattage, if it isn't marked on the panel