Top critical review
Useless at best, and perhaps capable of ruining your battery
Reviewed in the United States on August 15, 2019
I bought two of these in May before going on an extended motorcycle tour of the Arctic. My other motorcycle and truck were fully charged when I left home. Both batteries are relatively new. The two solar chargers were installed according to instructions and placed in full sunlight for the duration.
I get home 79 days later and neither battery has enough power to crank.
A disappointing result. Especially since it's too late to return these non-working chargers.
Update: both batteries are done for and need to be replaced. I suspect they were overcharged all summer while I was gone. Today I put a multimeter on the two solar chargers and in varying sunlight they show charging rates between 19 and 20 volts.
I'm not sure what that means at the low amperage these things are rated for. Maybe someone here does.
In any event, I need to replace two batteries now. The truck battery was just eight months old. The other is a high-quality motorcycle battery that I typically take out of service at the 5-year mark while they're still working fine. The one cooked by this solar charger (if my suspicion is correct) wasn't even 3 years old yet.