Hello Valerij, TORQUEEDO point out the following on their website/ServiceCentre/FAQs: "For safety reasons, only a device inspected and approved by Torqeedo may be used, as otherwise damage to the battery or to the charger may result. This would void all warranty coverage." /// The instructions offer 3 charging options: 1) Charging the battery using the AC power supply unit AC IN / OUT 24 V, 4,16 A, 100W => Charging time (power supply unit) 10,5 h /// 2) Charging the battery from the onboard power supply, using a DC power supply in the range of 9.5 V to 50 V. The DC power supply must be able to provide at least 4 A. => Use the TORQUEEDO 12/24 V charging cable #32976#. /// 3) Using a solar panel; the battery can also be charged using a solar panel from the Torqeedo accessories range or using solar panels from other manufacturers. Batteries from 2015 or later (serial number starts with 15 or higher) provide this option. The panel’s open-circuit voltage should be between 15 and 50 V, and power up to 150 W peak is suitable. /// The 915 Wh TORQUEEDO battery includes BMS/charging technology. If we look at the limits mentioned for solar charging, we can assume that the BMS can handle max. 150 W charging power. For example, if you use this 12/12-30 B2B, it would provide 12 V x 30 A = 360 W, too much for the 915 Wh battery. My tip: Check the fuse protection of your cigarette lighter socket. If it is fused at 12 A, you can use the DC charging cable #32976# to fully operate within the limits of the BMS. Charging may be a little faster, but it certainly won't be furious!