[MrBasse]

Dont charge them upside down, but they don't have to be perfectly vertical. They are fine to charge on their side but they won't vent as efficiently. As long as you don't charge them at too high a rate they will be just fine. Lots of wheelchairs have their batteries on their side and they charge all of the time in people's houses with no issues.

Our batteries charge at a 45 degree angle at 2 amps and have never been a problem in over a year of charging and maintenance.