120v AC Chargers

No matter how much solar you have, sometimes you need to plug in to either shore power or a generator to charge up your batteries. There’s only a couple major things to look for when picking a traditional battery charger.

Customized for Lithium?

Has your charger been set up for charging lithium batteries or traditional lead-acid batteries? If it has, or it can be adjusted manually, then great, you’re good to go. If not, you’ll get mediocre charge performance at best, and at worst, it could try to send voltages too high for your batteries to accept and then you just have to hope the internal BMS in your battery does its job.

Charging speed / # of amps

Most battery chargers list how many amps (on a 12-volt nominal scale) they can put into the battery. They will sometimes also include their power conversion efficiency, but not always. Generally, the more amps the better, but there’s a few situations where you might not want to draw that much power.

If you’re running a typical setup where a generator is used to charge your batteries, and that’s the only job the generator is doing, then go ahead and get the biggest charger you reasonably can. By doing so, you’ll have to run the generator for less time, and everyone’s happy about that.

But, if you are running other equipment alongside the generator (such as an air conditioner, for example), then it might make sense to have a lower-power charger since the gennie might not be able to power both items at the same time if they’re both running at full load.

Another option to consider is if you’re going to be moochdocking or staying in parks frequently. If you’re moochdocking and trying to not draw a lot of power from your friend’s 15-amp outlet (with who-knows-what) also on the same circuit, it makes sense to have a smaller charger to help live peacefully with whatever else is going on. If you’re going to be staying in parks frequently, a lower power charger will be plenty to handle your regular charging since you’ll have shore power and can stay plugged in overnight or over multiple days.

Dedicated Charger or Combination Inverter/Charger

There are pros and cons to having either a dedicated charger or an Inverter/Charger combo unit. The dedicated charger is a less expensive piece of equipment and can be easily replaced if it fails. You also have the choice of what size charger you’d like. The Inverter/Charger combo means you’ll have less equipment in your electronics bay, and many can handle the switchover to shore power automatically for you. Some, particularly hybrid units, will let you set exactly how much power to tap off the shore power or generator source, and that can offer a lot of flexibility. These combo units, particularly the hybrid kind, can get very expensive though, and it they fail, you’re out both your inverter and charger.