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Mitsubishi 4WD Club Trev's Tip 27. |
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Trev’s Tips Exploding Batteries
Some of you may have recently been fortunate enough to watch the greatest bush legend of all times, Russell Coight the all Aussie Adventure, in a rerun of one of his episodes, Celebrity Challenge, on TV.
For many weeks during the release of this series I would sit back on the couch and laugh my head off at the ridiculous and eventually obvious antics that this character would get up to so it was with great fondness that I sat glued to my chair whilst this rerun was playing last weekend. It was during his demonstration of how to light (or perhaps not to light) a camp fire using a pair of jumper leads and a car battery (obvious, but still funny battery explosion resulted) that I was reminded of an article that Keith P had sent to me on the issues of exploding batteries.
It is an issue that many of us probably give very little thought to until it comes time to hook up a set of jumper leads or perform some other electrical work that may potentially cause a spark next to the battery.
For me I didn’t, and probably still don’t think, exploding batteries are all that common so why would I spend too much time worrying about it. I guess what got me really thinking was that the areas that I now have batteries located are not just under the relatively well ventilated area of the car’s engine bay but more riskily in the confined plastic protective boxes of my boat and camper trailer.
Many people in the club are also in the same situation as me where they have batteries in well sealed areas of their caravans or trailers to protect them from the weather. If there is no chance of a spark igniting leaking hydrogen gas from the battery then there will never be a problem, but what I hadn’t considered was the potential for battery charges, solenoids or lose terminals located close to the battery emitting small sparks that could set off an explosion.
My complete understanding of this topic comes from reading this article from Keith so it may or may not be totally correct but for anyone running 12 volt systems in their camping equipment it certainly is worth thinking about. All batteries vent some explosive hydrogen gas, even sealed batteries, but it seems that they mostly do it when close to full charge (70%+). Naturally, having an operating charger positioned right next to the battery in the boot or toolbox of your trailer greatly increases your chances of an explosion each time you switch on or off the charger because of the potential for this item to cause an electrical spark. This problem can be heightened by the fact that many battery charges can overcharge your battery promoting excessive build ups of Hydrogen.
Hydrogen concentrations of around 10% in the air are potentially explosive. A battery at near full capacity that is being charged at the rate of 20amps (quite high but doable by many fast chargers) can produce as much as a litre of Hydrogen per minute. See
http://www.caravanandmotorhomebooks.com/articles/battery_enclosures.htm
This means that if the battery is in a confined area of 10 Litres (small esky size) then the 10% concentration mixture will be reached in 1 minute. In a larger 50 litre tool box it will take 5 minutes to reach 10%. Scary thought.
It is not my intention to scare the Sh#@$%t out of people but merely raise the awareness of the potential risk and perhaps encourage you to do some preventative maintenance buy checking out your 12 volt setup and if some modification of it is required then do it.
Till next time
Happy 4wding
Trevor It is my intention to live forever; So far so good.
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