Onami

Battery died in the C2S...which battery would you suggest?

tjangi

Lots have been written about this... My conclusion: Interstate. Reasoning: the weight saving is not worth the hassle of battery tender, poor performance of holding charge, and risk in getting stranded.

I have an Interstate for the last 6 years and still going strong, never died during wintertime even without battery tender.

AOW162435

Interstate.


Andreas

TxnBluDvl

I have a Optima Red Top in my M3 and a Yellow Top in my 993. I much prefer these since they remove the risk of acid vapor/overflow.

IXLR8

East Penn 648MF or if you absolutely want an AGM, East Penn 9AGM48.

Except for the case colour, the East Penn 648MF is physically 100% identical to the Porsche battery I replaced.

I prefer flooded lead acid batteries over AGM for the advantages that matter to me.

g_murray

My 6+ year old interstate died April 2009 -- changed to an Optima Red-Top. The installation was straightforward but make sure that the battery 'clamp' DOES sit on the plastic base of the battery itself. The fact that it is SEALED made, obviously, the 'vent overflow' completely redundant -- which I like. I do put a 'tender' on it (periodically) during the winter and have NOT had any problems since. The battery was approx $100, BTW.

Gerry

IXLR8

Well AGM or GEL "Sealed Lead Acid" (SLA) batteries are not really "sealed" and have a valve in order to vent.

They vent during overcharging or any condition where internal pressure is excessive (for safety reasons).

That is the problem with "Valve Regulated Lead Acid" (VRLA) batteries which is what AGM and GEL types fall under. When they are being overcharged, and that happens without you even knowing it, they slowly lose water which cannot be replenished as in a "Flooded Lead Acid" (FLA) battery. So when do they get overcharged? In the hot deep south when your car is overcharging them or when your voltage regulator has failed.

Which is why I prefer FLA batteries.

Besides, the CCA advantage of an AGM is hardly needed the way our cars are used.

Rinty

Mark:

I got an Interstate last year, and it went in real easy. Just make sure you get the vent kit with it.

milrad

I put a DieHard International Group 48 in mine. No problems with installation, durability (so far) or fitting the vent hose. Plus they are easy to get at Sears and return if necessary.

mike cap

Diehard International + 1. Perfect fit !!

IamSMC

You have a picture of that?

Pete Lech

After 8 years, there was no visible corrosion on my Red Top when I replaced it. Doubt if you could say that with a standard battery.

Interesting that the cheap battery I took out of the 993 and put into the 525 (under the back seat) is still going strong, and has never had a tender on it. The 993 did and the Red Top died after 8 years.. Perhaps the BMW has a better power management system?

IXLR8

I take it you mean corrosion at the terminals? My 11 year old OEM battery in my Honda is a standard battery and the terminals are still like day one. They were never cleaned or greased either.

Its a matter of design and quality control.

Pete, don't get caught needing capacity though. Most batteries I have tested had plenty of cranking ability (they passed a load test at 1/2 the CCA) and that is all we judge a battery by if we are users.

But if your alternator or alternator belt fails, chances are you'll never make it home on battery power alone unless you are close to home. I made it home from 110 miles away because I installed a new battery. There was nothing wrong with the old one; it started the car and it even marginally passed a load test, but I noticed other signs that had me replace it.

Rinty

A special trip out to the garage, in the rain, to take this pic for you, my friend :



I put away my tools many years ago, but installing this was an easy 10 minute job. I like the flooded lead acid batteries for applications where access is not an issue.

DanL993

That's what's great about this forum. I'm not looking for a battery right now, but this discussion is worth printing and saving.

Lotsa great advice here. Thanks guys.