Battery discharge question

[swhalen]

Hi All:
I had some minor work done on my 06 by a body shop that I have used extensively over the years. I went to pick up the truck on Thursday at the close of work because I took Friday
off for long weekend and wanted to leave town at the crack of dawn. I find out that the key had been left on, discharging the batteries. I was livid, but did not say anything or let it
register on my face, went home while they charged the batteries over nite and picked the truck up when the shop opened. I had hoped to have been long down the road by then. I questioned the service manager and found out that the truck "clicked" but did not turn over when they had discovered the problem and that they had not unhooked the terminals when charging the batteries, as I had requested. I drove the truck home and pondered this all weekend. I am all about preventive maintenance and these were diehard platinum group 65 batteries (rebranded Odyssey). I would prefer not to have words with this shop as they have done some minor work gratis, as a valued customer. So, to determine whether I need to talk to these guys or not my questions are: (1) Is there any possible damage to my alternator or other electrical components from charging the batteries, without unhooking the terminals; (2) are the batteries toast. My experience is that fully discharged batteries don't show the damage till the winter, when asked to work hard starting a vehicle?
thanks, steve whalen

 

[lpennock]

1. Probably not issue. I've never unhooked to charge. Only unhook to isolate when testing.
2. How old are the batteries? Could be they were already going bad.

 

[phantomusa]

You need to have the battery's load checked if they are good then your good to go if they fail mote then likely they where on the down hill side anyways

 

[AH64ID]

I would have them load tested.

Sears dropped the Platinum line because most of the batteries were only lasting 4 years, which is too short for the price.

My P2's were failing and I should have replaced them sooner and didn't. It cost me an alternator rebuild from the brushes working so hard to maintain the P2's.

 

[Tuesdak]

No need to unhook the batteries for charging: after all this is what the alternator does all the time with everything hooked up. Now you NEVER want to use a starting booster setting from a charger as that's is just asking to blow something electronic.

You should have better luck recovering from a full discharge of an AGM than the standard flooded batteries. A full discharge can kill a marginal battery. It's good that they charged the batteries for you as low AGM's will work any alternator hard if you just jump start it.

Load test your batteries and call it a day. Note heat reduces the life of batteries so if you live in a hot climate like Las Vegas or Phoenix that sees a lot of triple digit heat you normally only get 2-3 years out of batteries.

 

[Prairie Dog]

I would say no and no.
The alt. dumps a lot of dirty AC into the battery's when charging without detriment and while it's technically bad to discharge down to zero percent charge, the life taken from doing it just one time is negligible.
It does show a lack of care for a customers vehicle to do such a thing though.

 

[sag2]

Don't over think it. At the training center the batteries go dead all the time because they spend so much time KOEO when they are used for training. I have taken those same vehicles all over the west with never a battery problem. The Jeeps are using AGM so it should be similar to your's. I would have to say it would be a sad day when a battery (yes any battery) could not recover from going dead once.

 

[swhalen]

Hi All:

I got distracted by 4 days of rain and delayed by cataract surgery, but addressed the problem and here is the resolution. Charged the batteries individually and load tested them. Both registered more than 900 CCA, compared to the advertised rating of 930 CCA, so all is well. So, as Sag2 indicates, I overthought the situation. Thanks to all for the suggestions.
Regards, steve whalen

 

[MichaelOverfield]

For AGM there is a specific procedure to recover a deeply discharged battery, here is the link: https://www.google.com/url?sa=t&sou...aAbH7_NEQsWkpgriQ&sig2=6ItVcl2g1ZB8ljQ2n0lBRQ