Putting a vehicle, caravan or boat away for winter? 12V solar chargers are perfect for winter maintenance of 12V vehicle starting and caravan/boat (leisure) batteries. But which is best for you?
There are numerous 12V solar trickle chargers available and choosing the right one can be difficult. Cheap is tempting but not always cheerful and who should you believe when it comes to performance and quality?!
Well worry no more. Here is Ecofreak's definitive guide to choosing the right 12V solar battery charger for winter battery maintenance.
What size solar charger do I need?
Whether you are wanting to maintain a starting battery or leisure battery doesn't really matter. The size of solar charger you require depends on the size of your battery. Battery size is measured in amp hours (Ah).
10W : 100Ah
As a rule of thumb we work on a ratio of 10W of solar power for every 100Ah of battery capacity. This will ensure adequate winter battery maintenance and provide a reasonable amount of charge in the summer to offset power used for 12V lighting and appliances used in boats, campers, caravans etc.
Less than 10W : 100Ah
If you are just wanting to keep a vehicle battery topped up during the winter or through a period of prolongued disuse, provided there is a not a known problem with battery drain this ratio can be reduced. Any amount of solar input will help, but the lower you go the greater the chanc eof coming back to a drained battery!
The smallest solar charger we sell is the 1.5W 12V Solar Trickle Charger - this would be okay winter maintenance of a small 12V battery such as that used on a motorcycle or possibly a small car.
Greater than 10W : 100Ah
If you are charging a 12V battery that will provide you with power for 12V lighting and appliances (typically on a boat or in a camper or caravan) you may want to exceed the 10W : 100Ah ratio. There is really no limit to by how much you exceed the ratio as the more solar panels you install the more power you will have availble to use.
However, if you exceed the 10W : 100Ah ratio (and there is often very good reason for doing this) it is important that you incorporate a solar charge controller (solar regulator ) into your system to protect your battery from overcharging. The solar charge controller will also manage battery charging to maximise solar output and may, depending on model, give you system status and battery state of charge information as well.
Solar trickle charger, solar charger, solar panel? I'm confused!
Solar chargers are referred to as all of the above. All of the solar panels and 12V solar chargers on our website are designed for 12V battery charging duties so really all you need to worry about are a products individual features and the wattage.
We have a range of small 12V solar chargers designed specifically for easy use and regular connection and disconnection :