found an old solar panel. ok to trickle charge with>

[nyx2k]

found an old pv panel at the dump. about 18ins sqaure. tested it with a multimeter but havent a clue really how to use it but i think it was giving out 0.3 amps and 22.5v. does that sound about right.
can i use this panel to trickle charge my leisure battery or do i need a controller.

 

[VicS]

found an old pv panel at the dump. about 18ins sqaure. tested it with a multimeter but havent a clue really how to use it but i think it was giving out 0.3 amps and 22.5v. does that sound about right.
can i use this panel to trickle charge my leisure battery or do i need a controller.

I take it 22.5v was the open circuit volts. no load just what the voltmeter reads and that 0.3 amps was the maximum obtainable when an ammeter was connected directly across it.


That would be about right for a 5 watt panel although just about large enough to be 10 watts

If only 5 watts you do not need a regulator.

If it is 10 watts and the battery is any smaller than 100Ah I would fit a regulator .


It may or may not have a blocking diode fitted therfore I would fit a suitable Schottky diode in series with it to prevent reverse current flow at night in the event that it does not already have a diode. A Schottky because it has a low volts drop so no great extra loss if there is already a diode

 

[nyx2k]

perfect thanks. will look into that. at the moment its on the drive. if i connect it to the battery of 110am hrs will it be ok during the day to keep it topped up and disconnect at night for now. it runs a fish finder for a few hours once or twice a week. if it gets used more i can charge it from a good car charger i have.

 

[VicS]

perfect thanks. will look into that. at the moment its on the drive. if i connect it to the battery of 110am hrs will it be ok during the day to keep it topped up and disconnect at night for now. it runs a fish finder for a few hours once or twice a week. if it gets used more i can charge it from a good car charger i have.

sounds a sensible idea.

A 5 watt panel is all that keeps my boat battery charged ... at least it would if the boat was in commission ....

 

[William_H]

sounds a sensible idea.

A 5 watt panel is all that keeps my boat battery charged ... at least it would if the boat was in commission ....

Whats this Vic? Are you wasting a perfectly good summer with boat not in commission. That is a shame. I am afraid weather may not get much better and certainly will get worse soon. Hop to it mon....Failing that come visit 32 degrees south. I am looking forward to relaunch in about 6 weeks.
Re solar panel yes it would be excellent to charge the battery. No regulator needed. Connect it and confirm you get about .3 amp charge in sun. Fit a small fuse at the battery end of the wire. Re blocking didoe I have checked and could measure no reverse current in the dark yet it seems to be the done thing so yes fit a diode. If you have any silicon diode then use that. The extra volt drop about .3 more will not really make much difference but certainly schotky are best. good luck olewill