Review on 🔋 Topsolar 10W 12V Solar Panel Charger: Portable Battery Maintainer for Car, Boat, Motorcycle, Tractor by Devin Jenkins

I tried several brands and returned before keeping this one. The built in charge controller does exactly what the AC powered model does; It delivers the correct voltage during the three charging phases (bulk, absorption and float). Testing this panel on a fully replaced (12.9V) 35Ah lead-acid battery with a Bluetooth voltmeter showed that the voltage rose to 14.50, stayed there, and then dropped. for trickle charging 13.20V. This is ideal for lead acid. It only puts out 0.65 amps of sunlight at best, so don't expect to charge a completely dead car battery (maybe a week or two, lol). The controller provides the correct voltage and does not overcharge - Features a diode to prevent the battery from being drained into the panel in the dark of night which do not have these features. Cons: Both the panel and three accessories (clips, cigarette lighter plug and cable for eyebolts) have a socket. To connect them you need to use the included cable with a connector at each end. Why? Every existing DC power supply has a plug that fits into an outlet. So if you lose/forget or damage the cable with connectors on both sides, you cannot connect the panel to the accessory directly. I deducted a star for violating universal DC jack rules.