How to improve your battery charging while boondocking

Nancy in Casa Grande, Arizona has questions about battery power:

“We are interested in upgrading the battery in our Airstream, and the converter to one that will charge via the generator better than the factory model. We want the battery to last longer when we dry camp, and have a converter that charges without running the generator for hours on end. The Xantrex was really overkill for us and the price for the amount of time we spend dry camping seemed a bit high. Is there a less high end unit available (we really don’t need a lot of the features)?”

Nancy, good question—and you’ve actually asked two separate questions. First, no matter what type of battery you use, it can only put out as much power as it can store. So to get more camping time when “off grid”, you need larger capacity batteries or more batteries (or both). Look at the “C/20” amp-hour rating of batteries—the higher, the better.

The trade-off will be increased weight, size, and expense, so think carefully about how much power capacity you need. Also consider where larger or more numerous batteries will fit in your Airstream. A professional solar consultant can be very helpful here.

Your second question was about the converter/charger. Upgrading the converter/charger won’t dramatically speed up the charge rate of the batteries. The battery is the primary limitation when it comes to charge rate. A “3-stage” charger will help a little, but you’ll still be running the generator for hours to get the battery full.

TriMetric 2020
TriMetric 2020

A better choice for frequent boondockers is a solar panel in conjunction with your generator. Use the generator for short “bulk” charges when the battery is low. Turn the generator off when the battery reaches about 80% or the charging rate slows down to a trickle. Then let the solar panel do the rest of the work over the course of the day.

You’ll need to install a good battery amp-hour monitor so you can see the battery charge rate, which will add about $200 to the tab, but for extended camping without power hookups it’s well worth the investment.