RV FEATURE
DC-DC STEP-UP CONVERTER
You ’ re probably familiar with DC- DC chargers . DC-DC converters are slightly different in that they are designed to deliver a constant output voltage , rather than a variable output required for battery charging . While they are not very good for recharging regular batteries , they turn out to be ideal for recharging solar generators . They work by simulating a solar panel connected to the solar generator ’ s internal MPPT solar controller .
There are several available on the market but the most popular unit used for this application is the Victron Orion 12 / 24-20 converter . When connected to your vehicle ’ s alternator , it will step-up the input voltage to around 28V . Most solar generators can accept a DC input of up to 60V so this is well within their limits .
If you want to carry a petrol generator to recharge your solar generator , you only need a small one . 800-1000W is enough
Some methods of using your car ’ s alternator to recharge your solar generator will draw a considerable current .
At this voltage , you can expect charge rates of around 400W . At that rate , you could fully recharge a 1000Wh solar generator from near flat in less than three hours , or a large 2000Wh generator in a day ’ s drive .
Be careful when choosing this option , especially if you intend to fit it yourself . At 400W , the Victron Orion will pull around 30A from your car ’ s electrical system . That is a fair amount and will require good-quality cabling and connections to work properly . Also , these converters have no automation built into them . If you leave it switched on when the engine is turned off , it will drain your car ’ s battery in as little as a couple of hours . The Victron Orion does have the option of fitting a remote switch , however , which will protect your battery as long as you remember to turn it off .
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