GoRV - Digital Magazine Issue #49 | Page 60

Follow the manufacturer ’ s battery charging specifications so you don ’ t void the warranty
4 ) Generators : some have a 12V output that allows you to connect directly to a 12V battery . They are unlikely to charge more than 70 per cent as the generator will have a fixed voltage output , which is not high enough to charge a battery properly .
5 ) 240V mains battery chargers : there are multiple brands and types on the market . These range from small , basic portable units that connect using alligator clips , to a fully integrated battery management system ( BMS ). They all work differently .
Whether you choose a fixed system or a portable unit for multiple uses , it ’ s important to get the right type that suits your needs .
MAINS CHARGERS
Whether you opt for a portable 240V charger or a fixed one , like a BMS , how it delivers charge to the battery will come down to how ‘ intelligent ’ the charger is . Nearly all battery chargers today are referred to as smart chargers . But what does this really mean ?
Depending on the brand and type , the word ‘ smart charger ’ will differ in each of these product offerings , which can get a little confusing . Some will claim to be a ‘ set and forget ’ charger , where the charger can be left attached for extended periods of time .
Some might also claim to be threestage chargers , while others might state nine stages of charging .
So there ’ s lots to consider ! Many modern chargers have sophisticated electronics and offer a variety of features and stages , but fundamentally it comes down to three : bulk , absorption and float .
• BULK
This is the first stage where the maximum amount of current ( amps ) is applied to the battery to increase its voltage .
• ABSORPTION
In the second stage , the voltage is brought to the maximum for that battery type . It can range from 14.4V for wet cell flooded batteries , to 14.7V for some AGM types .
While voltage remains high , the amp rate is lowered . This has the effect of soaking all the cells in the battery and is critical to bringing it to a fully charged state .
• FLOAT
The battery is considered to be full in the third stage . The amps now applied to the battery are significantly reduced at around 1- 2A , while voltage is held constant at around 13.6V . This is perfect to keep the battery at maximum charge and ready to go .
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