I went with an Advance Auto battery 2 yrs ago, around $150 after online coupon. I'm already seeing a voltage drop to around 12.2 volts (60% charge) left to sit for 4 days in a heated garage with alarm off.

Seeing OE batteries last over 8 yrs and replacements lasting only 2 or 3 yrs has me looking at lithium-ion batteries.

Seems manufacturers/retailers are designing/providing lead-acid batteries that fail during the pro-rated period to get the repeat customers (% discount off full retail price).

The 8 times life of the lithium-ion is worth the additional cost IMHO. I'm not subscribing to their pro-rating game anymore!

I'm also not a fan of the car sitting garaged on the battery charger, I know it's vented, but what about the corrosive effect of fumes on areas/materals adjacent to the vent point?

__________________
'03 X5 4.4 Sport, last of the M62s (8-03 build date)
I believe in deadication to craftmanship in a world of mediocrity!