GoRV - Digital Magazine Issue #49 | Page 61

RV FEATURE
Note : For lithium batteries , it ’ s far better to use a charger that has a specific lithium profile . Special precautions and know-how is necessary to avoid any long term damage to the battery , as some smart lead-acid style chargers have other modes such as equalisation which will damage a lithium battery .
WHAT TO BUY
Whether you ’ re looking for a portable charging unit or a fixed solution that is secured permanently in the van , you ’ re ultimately looking for a charger that collects information from the battery and adjusts the charge , i . e ., current and voltage ( which is based on the information it gets from the battery ).
Regardless of whether you are after fixed or portable charging , consider what battery sizes / capacities you ’ re trying to charge ( how many amp hours the battery can store ). It ’ s important to note that there ’ s manufacturer information on batteries that indicates the maximum current amp rating the battery can take on recharging .
It ’ s pointless to get the biggest rated charger , say 50A , when the recommended maximum feed in current might only be 25A for that particular battery .
So how do you know what size charger to buy ? As a guide , take the amp-hour rating of the battery , i . e ., its capacity in amp hours , and divide that number by the charger ’ s amps rating . Then add a small percentage , say 10 per cent , to allow for a total topup of the battery . For example , if a 100Ah battery went totally flat and you were to use a 10Ah charger , it would take 11 hours to recharge the dead battery to be 100 per cent fully charged .
A quality charger usually comes with small lights or a blinking light that pulsates at different interval frequency rates to indicate which stage of charge it ’ s in at any given time . They also may come with a diagram of a battery and the light bar to indicate its state of charge .
An example of how linear charging and three-stage smart charging differs
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