RV Battery Chargers: Questions and Answers

Why do I need an RV battery charger?

In short because the 12V energy delivered by a battery needs to be replenished and it cannot be done effectively simply by connecting up another battery. A modern RV 12V battery can be and often has to be charged from multiple sources – tow vehicle or motorhome alternator, mains charger and solar panels are the most common sources.

What is the best RV battery charger?

One that matches the type of battery being used and integrates into the overall electrical system. Absorbed Glass Mat (AGM), gel cell and lithium LiFePO4 batteries for example all have different charging requirements. A charger that not only keeps a battery fully charged up but in a way that gives a battery a good economic life is essential. BMPRO has range of chargers that vary in size from 4.0 – 25A, with a variety of charging styles. In other words, something for everyone.

How does a battery charger work?

In short, when a battery is being used to power a device, a chemical reaction takes place that causes electrons to flow between the positive and negative electrodes via the electrolyte. What a battery charger does is to reverse that chemical reaction, thus recharging the battery. A typical charging voltage for a 12V battery varies between 12.9V and 14.4V. Whilst a constant voltage and current will charge a battery quickly, it’s considerably better for a deep cycle battery’s health if a “trickle” charge is used over a longer period of time. Multi stage chargers are considered best for this purpose. Lithium LiFePO4 batteries operate a little differently but the same principles apply, in that an appropriate charge is best for maximum battery life.

Can I use an RV battery charger to jump start my car?

No. Not only is that likely to damage the battery charger, it’s unlikely to be rated high enough for the necessary starting current. Far better and more effective to hook the battery up to a charger and read a good book for a while.

Why can’t I run my battery to dead before recharging?

Why would you want to unless desperate? Lights will dim and devices like fridges will simply stop working. Constantly running a battery to a dead condition will shorten its life considerably. A totally discharged battery may not be able to be revived by a conventional battery charger. However, the latest generation of BMPRO chargers have a feature that may revive an apparently dead battery.

What does charging profile mean in reference to a 12V battery?

There are number of different types of batteries but for RV purposes, there are several that come under the lead acid, deep cycle classification. Those being wet cell, gel cell and AGM. Both gel cell and AGM batteries are considerably more expensive than wet cell but do offer an overall better service. In addition to those, lithium LiFePO4 batteries are making inroads into the RV scene, particularly where high 12V loads are being anticipated. A charging profile is simply a reference to the way both voltage and current vary during a full charge of a battery and that does differ depending on the type of battery.

Why do different batteries need to be charged differently to get the best out of them?

Mostly because they are functionally dissimilar and constructed in a different way. As an example, a lead acid battery when fully charged will have a voltage of around 12.6 – 12.7V, whereas a lithium LiFePO4 battery has voltage circa 13.3 – 13.4V at full charge. At 20 per cent capacity, a lead acid battery will have a voltage around 11.8V, whereas a lithium battery will hold its voltage at approximately 13V. Without getting too technical the lithium LiFePO4 battery has a much smaller voltage tolerance and because of that, the “trickle” charge of the deep cycle battery does not apply. That apparent disadvantage does mean a lithium LiFePO4 battery can be charged faster whilst minimising the risk of overcharging.

What do batteries need to charge correctly?

A battery charger matching the battery has the necessary electrical current capacity, adjustable output and a charging profile/compatibility to match the battery. BMPRO has a range to suit every battery.

How do relevant BMPRO products aid charging?

Generally speaking most batteries these days need little maintenance attention. Since many are fully sealed, items like the ‘topping up cells with distilled water’ task have long gone. However, on the electrical side of things, there is still a “maintenance” function but it is all done digitally. BMPRO’s range of battery chargers is specifically designed for the RV world and has essential features like the capability to charge various battery sizes, multi stage charging, adjustable charging outputs and multiple battery type compatibility. In other words, something for every RV.

Why do consumers need a BMPRO charger?

We all live in a busy world even when enjoying the outdoor lifestyle. A good battery charger will have a “set and forget” feature, meaning one set up properly allows more time for essential activities like “Happy Hour”.