Charging Batteries Safely

A news item out of Yuma, Arizona, last month points to a couple of reminders--and a product lead--that could affect your safety as an RVer.

Imagine waking up at one in the morning with your smoke detector going off, and that awful sound of a roaring fire outside your bedroom door. It happened in mid-June to a Yuma couple, who were planning an outing with their motorhome. Apparently having a low battery problem with the motorhome, the owner had hooked up a battery charger and left it. Sadly, the battery overcharged, and the resulting heat ignited a fire. In the end the motorhome and the family home were completely wiped out. You can find the whole story on the Yuma Sun website.

We've been around battery chargers since we were 'knee high to a married grasshopper' and some of the "oldy" chargers that our pappy's owned were probably hanging around when they were knee-highs themselves. It just seems like battery chargers are one of those products that rarely give up and die. As a result, many of us are limping along on ancient technology that may work--albeit inefficiently--but can (as it apparently did this time) lead to tragedy.

A lot of us use portable battery chargers, and many of these fall into the category of what's technically called an "unregulated charger." Hook it up, the charger delivers a charging voltage (higher than the "rated" voltage of the battery) and just keeps a charging. The battery voltage increases as it charges up, and it will eventually reach a point where the electrolyte will literally boil. An unregulated charger needs to be monitored. Yes, with this type of charging system, you would want to occasionally hit the boiling point to "equalize" the charge in the cells. However, if you "cook" them too long, you'll kill the battery, or even worse--lead to a fire danger.

A complete discussion of battery charging is an appropriate topic--and we'll cover it in a future blog entry. Now, however, we make this point: For many it's simply safer, and far more efficient, to use what is termed an "intelligent charger." An intelligent charger recognizes the state of the battery's charge, and supplies exactly what is required at any given stage in the recharge process. Enter the Xtreme Charge maintenance charger. A relatively inexpensive ($99 list) charger, Xtreme is an "intelligent charger" that also adds an additional benefit: This charger "pulse charges," inducing a wave into the charging current that breaks up sulfate crystals in batteries. These sulfate crystals, if left to themselves, will eventually kill off an otherwise good battery. The Xtreme can be left hooked up to the battery, and it will maintain a safe current level, along with the sulfate-eradicating pulse.

Xtreme's manufacturer sent us an evaluation unit a couple of months ago. While we're still testing it, so far we've been pleased with it. It's a small unit that can fit in many battery compartments, and even if it won't it's weather proof, so you don't need to worry about a passing rain shower shorting out your system. While the specs indicate the Xtreme is designed for battery systems up to 150 amp-hours, the company whiz-kids tell me that it will work with larger systems, but its relatively low (2.5 amp) maximum charge current will take a while. Amen to that. For a larger system, consider the Xtreme a good investment in battery maintenance, rather than full-scale charging. Find out more at the Pulsetech website.

There are also "intelligent charging" systems available on many after-market (and some OEM) RV converters--those little devices that convert shore power into low-voltage power, suitable for use by RV interior lighting and other uses. In any event, when you hook up a charging system to your RV batteries, make sure you keep an appropriate watch on it--particularly if it's an unregulated charger.

Fire Photo: Yuma Sun Charger: pulsetech.com