SUNER POWER Waterproof 12W 12V Solar Battery Charger & Maintainer Pro

Hands-On Review: Upgraded Waterproof 12 W 12 V Solar Battery Charger & Maintainer Pro

After three weeks of real-world testing on an RV house battery, a parked sedan, and a riding-mower lead-acid pack, this waterproof 12-volt solar trickle charger proved itself a compact, fuss-free solution for off-grid battery maintenance.

First-Use Experience

Unboxing is painless: the 16.5 × 9.4-inch monocrystalline solar panel arrives pre-wired with an SAE quick-disconnect, an inline 10 A fuse, alligator clips, ring terminals, and a cigarette-lighter plug. We mounted the panel on the RV roof with the included stainless brackets; on the sedan we simply set it against the windshield and snaked the cord through the cracked window.

SUNER POWER Waterproof 12W 12V Solar Battery Charger & Maintainer Pro, Built-in UltraSmart MPPT Charge Controller, 12 Volt Solar Panel Trickle Charging Kits...

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Charging Performance

A cloud-free midday in Arizona delivered a steady 0.85 A (≈ 11 W) into the RV’s AGM battery—respectable for a nominal 12 W panel. The built-in MPPT charge controller consistently held battery voltage at 13.6 V in float, then dropped to 13.2 V overnight with zero reverse leakage. On overcast Pacific-Northwest mornings output hovered around 0.2–0.3 A, still enough to offset parasitic draws from the truck’s alarm system.

True Waterproofing

We left the panel outside during two spring storms; water beaded off the ETFE-laminated surface and the junction box stayed bone-dry (IP65 rating checks out). No signs of delamination or hot spots.

Compatibility Checks

– Lead-acid (flooded/AGM/GEL): perfect

– LiFePO₄: controller tops out at 14.4 V—safe, but you’ll only reach ~95 % SOC on some packs.

– Vehicle OBD-II plug-in: cigarette adapter works, but we preferred direct ring terminals for lower resistance.