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what is the proper way of disconnecting the battery terminals? remove the positive first then negative and re-attach the neg. first and pos. last? but then i heard someone said to remove the neg. terminal first. to prevent shorting. which is correct? what are the proper steps? do i need to remove any fuse before i jump-start the car?

also, how do i check and fill up the water level in my battery? what do i need to remove since i can't see the water level from the outside. i still have the stock battery on my stock E36 M3.

TIA

There should be six circular plastic plugs, all in a row, on the top of your battery. If your battery still has the sticker on the top, peel it off and you'll see the plugs. You can use a coin to unscrew them. Then you can top off the water levels in each cell.

Use distilled water to top off the battery, and wear rubber gloves to protect your hands from the acid that's on the plugs.

disconnect ground cable first,, the reason is to reduce amount of sparks.