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Is your box/batt vented? I think this doesn't apply to sealed batteries, but the last unsealed batt I installed came with a small clear plastic tube that connected to a nipple on the batt case and meant to pass through the box to outside air. While you may want to investigate any possible overcharging, the vent would certainly help the situation.
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
If it was caused by vapour from the battery I would expect it to be clustered on one pole, not spread out like that. Check for acidic as Greg suggests, or maybe get a tiny grain and touch it on your tongue lightly - you will know quickly if its acidic. Sure its not stuff fallen in from outside the box? Some of it is outside, so what's above the compartment?
jp 83 Euro S AT 57k
Looks like acid as it's concentrated at that front terminal connection - see that corner of the battery box and it inside the terminal circle. That's probably where your vent outlet is located.
Since there is "snow" on the outside of the box, also, I'd try to confirm if that is acidic based.
Take a little bit of baking soda and water on a little sample of that dust and see if there is a reaction.
Having Greg tell you that you have a condition that he’s never seen before is not encouraging.
Let me do some testing, I had a great run in it yesterday until near the end of the drive and now it’s stumbling and threatening to die if I give it more than quarter throttle travel, but that battery “snow” was there before that so not linking those at this point.
Your batt looks like a sealed unit? The "12/18" = Dec 2018? Do you have a maintainer on it? A maintainer on a sealed unit is unlikely to do that. A charger, maybe so if it was pushing a lot of electrons into the batt.
I'm curious about the taste test.
12/18...that battery should still be under warranty.
Also AGM batteries have vent ports that need to be utilized when installed in passenger compartments. The 928 battery is in the passenger compartment and if/when something goes wrong with it or the charging system, it'll be a brutal way to die.
Time to get rid of the battery and put a sealed AGM in its place.
I have terrible results with AGM batteries, in the 928 application. Such poor results, I refuse to buy one when I need a battery for a client (often.)
AGM batteries do not seem particularly "happy" about being discharged below 50%...which is super common on most 928's that sit for a week. And if you drain an AGM down to nothing, they rarely recover.
Yes, a battery maintainer seems to help, but forget about it once...or have something go wrong with the connections, someone unplug it by mistake, or the charger "have issues" and invariably the AGM battery will be junk.
Totally agree with Greg on the AGM. Bought a top of the line one from Sears and had nothing but grief. Sears finally said it was bad after a year, I had it tested and charged numerous times. Swapped in a lead acid and life was back to normal. I can go out after not starting it for weeks and has plenty of juice. The AGM wouldn't go more than five days. And I didn't make any other changes. I have a Range Rover that had an agm in it too and it was awful. Tested bad after two years, AutoZone had a note not to use one of these in this model. Someone didn't read. Dropped a lead acid in and all is right again.
I have an Optima red top in my 928. Been in there since my build about 5 years ago. No issues and lots of additional electrical accessories - 1,000 Watt stereo, hid lights, pump for supercharger hear exchanger fluid, auto dimming and Homelink rear view mirror, infrared backup camera, electric door locks, etc
The last Optima I replaced in my 914 lasted 12 years. They also now have a yellow top which is a cross between a blue top deep cycle marine version and the red top starting battery. That's the one I've been buying now.
I went through 2 red top Optimas in my own car and they didn't last worth a damn. Put in a normal battery and have had it in there for over 7 years, good to go. Recommend the same for the customers cars as a few have had the same issues. I'm in agreement with Greg.
You have to go with what you're comfortable with. The Red Top Optima in my pickup is 6 years old, the one in my 997 is 6 years old, the one in my wife's 997 is 5 years old, just changed the one in my Mom's Infiniti at 5 years old for a Yellow Top, All of the ones in my cars sit on Battery Tenders when not being driven, which may be why they last so long, but never knowing which car I may take when, a car could sit for a few weeks to a couple months without being driven and why I just plug them in when I pull into the garage. Same reason I use fuel stabilizer in those cars with each tank. The truck gets driven every day.
03-07-2020, 12:18 PM
It’s snowing in my battery compartment
