Batteries that are used often have a life span of about 5 - 10 years depending on maintainace. Batteries should never be charged for short periods of time, a full 8-10 hrs. of charge and only when the battery requires the charge. Water (perferably deionized which reqires an expensive set up) should be added and should covering the lower plates of the cells after charging is complete ( make sure there is water in the cells before charging). If there is iron in the tap water, use bottled water.

An "equalize" on the charger may be present, that should be done every 6-9 months, again, depending on use.

It sounds like this machine probably wont be used a whole lot in your place, so equalizing probably wont be an issue. A low battery can cause damage to the truck during operation, so I would wait until the 220vac is available.

Just remember, charging a battery produces explosive hydrogen gas, a small spark makes a huge bomb blast. I never charge batteries over nite, I like someone to keep an eye out when charging. A customer had an older charger, the battery shorted internally and caused a fire at night. One of the most expensive part of the truck, is the battery, treat it nice.

Alot of information, hpoe it helps