Best place to get a battery?

[Manolito]

Arghh! Costco apparently no longer carries Group 48 batteries.

I would rather not fabricate a new battery holder to fit a different case style.

What is the best value in Group 48 batteries?

[Manolito]

BMW put a Group 92 Maintenance Free (unvented) battery in most e36s.

The battery bracket has a hole to fit a Group 48 battery, but you need to arrange for the vent tube, or it will blow acid mist out into the cavity and attack the paint and metal. There is a rubber plug beneath the battery where you can poke a small hole and route a tube out beneath the car. You have to run the tube beneath the full length of the battery to keep from crushing it beneath the weight of the battery.

The Group 48 is shorter, but is the same height and width and has the same hold-down ribs as a Group 92.



You will note that I cut the sealant tape and removed the cell caps from the old maintenace free battery several years ago. Even maintenance free batteries can benefit from being kept full of distilled water.

I don't necessarily recommend this Wall Mart battery, but the price was right. It is made by Johnson Controls like most other car batteries these days, so it is probably OK.

It is a 6-year pro-rated battery. That means that on average, the manufacturer thinks that it will last about 5 years. They put one more year warranty on the battery than they think it will last to encourage you to come back to them for your next battery. In the 6th year, they knock off only a few bucks as a discount for your return business. If I am careful and never let it go dead, and I don't subject it to 120 degree heat or subzero cold, it should last 7 years or so.

This last pic shows the hold-down and vent hose in place. There will be paint in the threads of the hole, so chase the hold-down bolt through it once before you install the battery, so the bolt will go in easier after the battery is in place.



Hold the clamps as you gently tighten them. If you abuse the battery posts, you will break the seals around the posts and the battery will vent through the failed seals, corroding your battery clamps.




Final note - If you drive a convertible, you must buy the special vibration resistant battery. Convertibles use the battery as the weight in their vibration dampening system, so the battery takes a lot of abuse. Regular batteries won't tolerate that.

[Jeron]

Walmart

[Yurick]

I would agree with Jeron on Wal-Mart, but I would also suggest Sam's Club or Costco.

[Manolito]

I don't know anyone with a Sam's club membership, and Costcos in Sacramento no longer carry Group 48, so I decided to give Wal Mart a try.

[Yurick]

You can't go wrong with a Wally-World battery.