Not really Maintenance Free.
Since today was relatively warm (upper 40) I decided to check out the battery on my X. During the past cold spell I had to hookup a maintainer to charge the battery. If the car sat out over night, by morning when I connected my maintainer to the engine jump terminal in the engine compartment, the maintainer would tell me that the battery was at 60 to 70% capacity. Some time it dip below 60% capacity. After charging the battery (usually for an hour) it would register 100% on the maintainer's display. My battery is not the original battery and it had caps on top. I removed all the caps and with the battery water fill tool that use to belong to my dad I filled all the cells up with distill water. It took a little less than half a gallon to fill all the cells. Hope this fix my low capacity problem. The car never fail to start, but one time my airbag came on (the coldest morning of the week 5F), but it went off the next time I went to restart the engine. Maintenance Free batteries are not always maintenance free.