We had a very unusual experience – one worth sharing. Our 5th wheel is 10 months old. We recently stopped at a campground with our grandchildren for a weekend in Michigan. I knew my “dump tanks” were empty, but I could smell a very strong odor of sewer gas. I thoroughly flushed all my tanks and the odor continued to intensify.
My problem was not the tanks, but the RV12 volt battery, boiling acid. It was actually releasing visible fumes into the air. The battery was so hot I needed pliers to disconnect the terminals. The battery was encased in a rubber boot hence it was not easily detected. The probable cause: (1) a loose terminal (which was not the case) or (2) fused plates in the battery. I had visions of the battery exploding with acid all over my body. The battery case actually bulged from the heat. I thought the experience was worth mentioning. Serious consequences could have occurred. Other readers should check their battery if they smell this type of odor.
Thanks for your letter. Sorry that I did not get back to you sooner, but my travel schedule is sometimes hectic. Batteries will overheat if the charging voltage from the converter is too high or if too much current is being drawn away. When they heat up, the acid can boil and emit sulphur fumes and hydrogen gas, and the positive and negative plates may warp enough that they create an internal short. The hydrogen gas is dangerous as any spark can make the battery explode throwing acid all around. Be very careful when connecting the cables not to create a spark near the battery.
Many RVers spend the winter months in a campground where they are connected to electric power all the time. They need to check the level of the electrolyte in the batteries each month and add distilled water to keep the cells topped up.
When RVs are in storage and not being actually used disconnect the negative battery terminal to prevent phantom loads from drawing current and depleting the battery charge. If your batteries are up to charge, a small solar cell can keep the battery charged from decaying due to normal chemical action. When our unit is in dry storage, we use a fivewatt solar charger from Pulse Tech, which send a short charging pulse once each second instead of a continuous charge.