Building a small solar supply, 0,3 Amps an hour charging, this works:
Plan is one battery as a spare on the roof (ventilation) and that can be used for the lights and charging phone to keep dual batteries full.
Solarpanel for charging a third 60 amp battery on the roof, also as a spare:
220x200mm 12V 5W Solar Panel charging with 13.2 Volt, output 13.1 V
SLA Battery Voltage:12V
Power: 18V 5W
Peak current : 0.29A
Peak voltage: 17.2V
Open-circuit voltage: 21.6V
Short circuit current:0.33A
Output Tolerance: ±3%
Material: Polysilicon
Size: 220x200x2mm (L x W x H)
Weight: 212g
And the controller:
Features:
Automatically manage the working of solar panel and battery in solar system.
Overloading & short-circuit protection.
Reverse discharging & reverse-polarity protection.
Under-voltage and over-charging protection.
Protection from lightning strike.
Prolong the battery life cycle and keep the load work well.
Easy to set up and operate.
Suitable for small solar energy system.
Specification:
Voltage: DC 12V / 24V
Self-consuming: 10MA
Rated Charge Current: 20A
Rated Load Current: 20A
Over charge:
Protection: 14.4V / 28.8V
Floating charge: 13.5V / 27V
Recover: 13.2V / 26.4V
Over discharge:
Protection: 10.8V / 21.6V
Recover: 12.3V / 24.6V
Load over voltage:
Protection: 16.5V / 34V
Recover: 15V / 30V
Max open-circuit voltage of the solar panel: 25V / 36V
Operating temperature: -20℃-50℃
Color: Black
Item size: 10.2 * 9.5 * 3.8cm / 4 * 3.7 * 1.5in
Item weight: 120g / 4.1oz