I didn't design the Bosch batteries, only reading the fact that both batteries are defined as "sealed", and "vented outside of vehicle".

See notes on batteries in link....

http://www.pepboys.com/parts/batteri...04.4L%2520DOHC

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