- Apr 26, 2005
- Under the hood
I think the choice depends on several factors:
1) Do you like a truly "maintenance free" battery that never needs fluid checks?
2) Do you never want to deal with the risk of corroded or crusty terminals?
3) Did the car come with AGM originally, is the charging profile optimized for it?
4) Do you daily drive the car? (that tends to lean toward flooded for a car that came with flooded)
5) If the car is a rarely driven car, then alternator charging profile probably has less impact, since it will be on a battery tender more than being charged by the cars alternator.
6) Budget, is the $50 or $70 going to break the bank?
I'm liking AGMs more and more, after going through a couple flooded East Penn batteries in my old daily driven BMW (2001) in short order. I have a AC Delco "made in germany" AGM now for four years, and still tests great on my load tester, exceeding its rating. I'm not finding the charging issue to be a big deal...I wonder if it really is. I noted that Consumer Reports in their testing, like AGMs and discuss their typical better performance and life. Though there are still some excellent performing flooded batteries, but depends on what size or application. They never mention the potential shorter life of AGM if charging profile is not optimal.
1) I've been told by a battery distributor, and concur, there is no such thing. Unfortunately, many modern battery cases don't have easily removable caps, and/or have ports covered by stickers, clearly intended never to be cracked open.
2) Not an issue. Vented trunk mount.
4) It can sit for 1, 2, 3 days at a time, before mostly in town duty.
I've considered the AGM question before, and now EFB, but it's not difficult to reach the same conclusion. Given the application, plus the fact that FLAs have served 6-7 year terms in the car with no issues, and such usage, I find it hard to justify the additional 50% cost of jumping from a $120 FLA to the $180 AGM battery. Or more, outside of a Costco or Walmart.
Exide, or their new parent, seem to be only one pushing EFBs in the U.S. currently, and the H6 I'd need is $230 with a Duralast label, or $220 with an Interstate label. The one with the Exide Marathon label seems to be only available through distributors, or as a catalog part, and that comes at the cost of convenience, if not price as well.
Clarios provides more information on the benefits of EFBs on thier site, mainly more cycles and better suitability to deeper cycling, targeting stop/start applications, but they also seem to have their own charging preferences, which merit further investigation.
At this point, a Duralast H6 AGM is only $10 more than the EFB, so whatever cost benefit they may have in Europe doesn't apply here, and given the other advantages AGMs have, particularly in newer applications, there's little incentive to refuse that option instead.
While EFB would seem to be a really good fit for me, the cost/benefit ratio isn't there yet, and may never be, unless the OEMs equip more vehicles here with them, and create a larger and more competitive aftermarket demand for them.
For now, neither pencils out for me, but as they say, YMMV.