In our block, the car spaces have individual lights with switches. These are wired directly back to the main switchboard, with a dedicated circuit breaker, for each unit, rather than the sub-board in the unit. A few spaces have had power points installed using the lighting wiring. I did have a problem a few years back with another resident using my power point to do some work on his car, but when I explained the situation he readily apologised and compensated me.
Perhaps Scott13 could consider buying a battery booster pack, which he could connect to his batteries occasionally to recharge them. He can recharge the booster from a power point in his unit.