During caravan power upgrades we change out the old AGM batteries to lithium batteries and in the process we often find swollen batteries.  

We see AGM caravan batteries swell for a few reasons, typically due to rapid over charging or slow over charging. 

Rapid over charging will cause excessive heat and a pressure build up to the point where the vent will relieve the pressure causing swelling and bulging of the battery casing.

Slow overcharging will generally cause positive plate oxidation and flaking, which will expand the cell and swell the casing.

BUT, as you will see in this video, another common reason for caravan batteries to swell is if the inverter in the caravan has a greater maximum load capacity than the batteries are capable.  Where the inverter and batteries are incompatible, and there is rapid discharge, the battery cells will likely collapse, and then follows subsequent charging.  This cycle of miss use will cause the batteries to swell and fail.   

Unfortunately, we see many examples of this in the caravan and RV industry.  It is due to a lack of technical knowledge and electrical experience by the installer, and results in being out of pocket and the cause of frustration for many caravan owners.

If you you have notice a swollen battery in your caravan or are running out of battery faster than you would expect contact Outech Off Grid Power Solutions to help identify the cause the problem.