Originally Posted by Ron07x5

Motordavid did not say I put charger on for two weeks, just 10 to 18 hours. Our use of x5 will be low miles often on level ground. I would like to know if we may deeply discharge the battery this way or not.

I meant, why wait to 'recharge' for two weeks? Unless it's not convenient, or you are running some kind of test. The low miles/rolling around town may or may not provide for keeping batt charged; in my experience with our cars, it does not. Or maybe it is OK, but hooking up our BT regularly is easy stuff, for 'prevention'.

So my plan is to manually charge at 1 then 2 and 3 month intervals. If manual charging time increases in like linear pattern then I will know we can face deeply discharging the battery.

Batts should go a month or more, and some surely do...my old 'company car' used to sit in airport parking lot(s) for 2 weeks straight, and I never trickle charges those car(s). That was then, this is now, with very different levels of electronics on cars, and maybe different/increased loads and charging req's.

I know once a battery has less than 50 percent charge the voltage it provides drops. If lower voltages cause systems to get flaky then I want to avoid that..

Seems nobody really knows what the algorithm of battery charging is so I am left to discover in part by this experimental manual charging.