Hoysicy
20W Monocrystalline Battery Maintainer
Historical Reference
This product is included for historical comparison and is not currently recommended for purchase.
Good solar production at 16.49 watts in sunny conditions. Heavy at 3.52 lbs. Charge controller failed - overcharged battery to 16.2 volts without stopping. Not recommended despite good solar performance.
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I Had No Idea These Were So Good!
Project Farm
Jan 18, 2026
Ranked #5
3.5
"Good solar production at 16.49 watts in sunny conditions. Heavy at 3.52 lbs. Charge controller failed - overcharged battery to 16.2 volts without stopping. Not recommended despite good solar performance."