Charging from solar panels

Solar panels are an ideal way to charge a battery. There are many different types of solar panels available from the inexpensive to the top of the range. They have improved considerably in the last few years offering practical power in compact sizes. Once installed, they require little or no maintenance allowing you to enjoy your leisure time knowing that you will always have sufficient power when it is required. A regulator is required with any solar panel above 22 watt. The regulator switches to pulse charging when the battery is 95% charged and turns off completely when charge is completed, turning on again only when required to keep the battery topped up.

Charging from generators

There are many different types of generators widely used, which offer a quick solution to charging a low / flat battery. Whilst using the generator to charge your battery, always ensure the electrolyte is above the plates. If your battery is low on electrolyte, you can inadvertently damage the plates of the battery and cause premature failure of the product. It is not advisable to leave your generator continually connected to the battery. Always disconnect the generator when the battery is fully charged, and follow the manufacturers guidelines on safety, (Important: To ensure no damage to batteries is sustained whilst charging with a generator, use a Multimeter to check charging voltage when 14.40V is reached, switch off the generator).

Charging from the boot of your car

Caravanners used to move their leisure battery into the back of the tow car to achieve a higher charge rate from the alternator. The caravan battery or a spare battery can be recharged simultaneously with the car battery from the car’s alternator and the most effective place to locate the caravan battery is in the car boot. (The shorter cable run, and the use of a larger cable, results in a greatly increased charge rate over a battery situated in the caravan).

The battery should be connected in parallel with the car battery that is the positive terminals are connected together, as are the negative terminals. Batteries should not be left connected unless on charge or they will attempt to equalize and so discharge one another. It is therefore essential to fit some device which will automatically disconnect the caravan battery when the car ignition is switched off.

A split charge relay is the most effective method and is suitable for all types of vehicle alternators. The relay will come with installation instructions including the size of cable that can be used. Ideally the caravan battery should be enclosed in a box fixed to the boot floor. With the engine and ignition switched off, the relay isolates the car battery from the caravan battery. When the engine is started or the ignition switched on (depending on the method of relay connections) the batteries are connected together and will receive a charge. If your battery has a venting tube, make sure this is routed to the outside of the vehicle. A battery charged or stored in the boot of a car must be secured in a suitable frame; if a battery were to overturn the acid would be a serious safety hazard. Even a ‘sealed’ battery has vent tube which would allow the acid to escape.