What amperage to charge a dead 8d?

TrevorH · January 31, 2008, 08:39:32 AM

I just pulled 2 very new looking 8d's out of a bus that has sat for a year plus. They are dead as a doornail. I added distilled water. At what amperage and time intervals should I charge them? The charger I have now does 2a, 10a, 15a but I just bought it so I can return it at any time. It is a microprocessor control unit that adjusts its perameters slightly as it senses the state of the battery. Thanks!

mike davis · January 31, 2008, 09:06:42 AM

Quote from: TrevorH on January 31, 2008, 08:39:32 AM
I just pulled 2 very new looking 8d's out of a bus that has sat for a year plus. They are dead as a doornail. I added distilled water. At what amperage and time intervals should I charge them? The charger I have now does 2a, 10a, 15a but I just bought it so I can return it at any time. It is a microprocessor control unit that adjusts its perameters slightly as it senses the state of the battery. Thanks!

get 2 big hot car batterys. I just did what your are doing to a bus on tus. mine started .Clean the battery terminals too it's. 65 in tucson today It will work

mike

DrivingMissLazy · January 31, 2008, 09:11:38 AM

Quote from: TrevorH on January 31, 2008, 08:39:32 AM
I just pulled 2 very new looking 8d's out of a bus that has sat for a year plus. They are dead as a doornail. I added distilled water. At what amperage and time intervals should I charge them? The charger I have now does 2a, 10a, 15a but I just bought it so I can return it at any time. It is a microprocessor control unit that adjusts its perameters slightly as it senses the state of the battery. Thanks!

Trevor, even with the charger set on its highest output voltage you will probably get little indication of charge current for several hours possibly. The main thing you need to do is check that the charge rate does not get so high that you have excessive boiling of the battery. I do not think that will happen for a day or so.

Richard

tekebird · January 31, 2008, 09:14:17 AM

20 or better for as long as 96 hours.

keep in ind a bad battery will still show charge but be unable to accept a load.

If suspect...just buy new ones

Tenor · January 31, 2008, 09:22:39 AM

Do you have a hydrometer to check the condition of the cells? If there are any that are dead, there isn't anything you can do but use them as cores for deposit.

kyle4501 · January 31, 2008, 10:07:32 AM

I brought the 8Ds in mine up from dead (small ghost drain killed them & I didn't notice for months) by putting my charger on 225A start boost until I heard them boiling, then put it on 50A for 6 hours. The 8V71 started then, but those batteries are toast & won't hold a charge like they should. I did this 'cause I needed to start it & didn't want to buy new batteries yet.

TrevorH · January 31, 2008, 10:50:49 AM

Not killing them as it seems you have Kyle would be my goal. I have no time constraints so I want to do it right. Should I cycle them ie charge for XX amount of time and then switch to the other battery, and so on back and forth?

mike davis · January 31, 2008, 11:14:48 AM

Quote from: TrevorH on January 31, 2008, 10:50:49 AM
Not killing them as it seems you have Kyle would be my goal. I have no time constraints so I want to do it right. Should I cycle them ie charge for XX amount of time and then switch to the other battery, and so on back and forth?

I started with my 8D's 10 days ago from dead There coming back But it is coming too the point of why mess with them. Call The Battery Factory on Oracle they sell them cheep

I live in tucson and have been working on buses ,cars trucks and have delt with them for years

mike

kyle4501 · January 31, 2008, 12:21:13 PM

Quote from: TrevorH on January 31, 2008, 10:50:49 AM
Not killing them as it seems you have Kyle would be my goal. I have no time constraints so I want to do it right. Should I cycle them ie charge for XX amount of time and then switch to the other battery, and so on back and forth?

My opinion was they were already toast before I charged them. They are over 11 years old & were in the bus when I bought it.

I assumed you just wanted to charge them up enough to start the bus once or twice to evaluate it as a potential purchase.

Jerry Leiber has a recipe for resurecting a dead battery . . . . . If it fits into your schedule. As for me, I have enough hobies as it it without adding saving old batteries . . . for now anyway.

TrevorH · January 31, 2008, 12:43:34 PM

These look new so I am trying to bring them back for as long as possible. A penny saved is a penny earned and I dont have nearly enough for the project I am about to begin!!

mike davis · January 31, 2008, 02:12:11 PM

Quote from: TrevorH on January 31, 2008, 12:43:34 PM
These look new so I am trying to bring them back for as long as possible. A penny saved is a penny earned and I dont have nearly enough for the project I am about to begin!!

2 8D' $200-$300

drag the stater for 20 sec.burn it out $450-$700 + paying someone to change it

starting the bus FREE 2 group 28 car battery
bus math is fuzzy math
I know you have bus fever So do I and everyone here The only thing I can say about that is ALL buses are money pits What some people here try to stay out of is the money canyons

good luck

mike

Barn Owl · January 31, 2008, 02:35:05 PM

Quote2 8D' $200-$300

drag the stater for 20 sec.burn it out $450-$700 + paying someone to change it

Mike said it the best.

Messing with a dead battery, even if it's new, is a waste of time...IMHO

Check out this link, it is a nice reference:

Popular Mechanics Complete Car Care Manual

http://books.google.com/books?id=39xxTCsBjUAC&pg=PA86&lpg=PA86&dq=automotive+discharged+battery+permanently+damaged&source=web&ots=00DkMYTveR&sig=tAShQBo7-TkYJbvQ6LJZNnxH09Y#PPA85,M1

Reddog · February 01, 2008, 12:58:57 PM

Another low cost approach might be to go to the local wrecking yard and buy a couple good, used batteries. I have bought many this way and have used some for a few years. Usually you can get them for 15-25 bucks. Another source is to go to a local battery shop (like Interstate) and get a couple used ones from them.
In my used battery buying experience, it always seems like the ugly ones are good and the pretty, new looking ones are junk. Don't know why, it just works out that way.
One other note, beware of taking out a good alternator by trying to make it charge bad batteries once the rig fires up.
Doug Engel, Gunnison, CO

TrevorH · February 01, 2008, 01:14:56 PM

The digital charger that I bought has a charge percentage of the battery and a voltage. Both batteries charged up to 64% within an hour or so. But it took the last 6 hours to get them to 67%. Any idea on what could cause this?

H3Jim · February 01, 2008, 01:22:08 PM

The last part of the charge alwayas takes a lot longer than the first part of the bulk charge. It one reason put solar on. Just running a generator for an hour or two a day should be enough to provide all the electric I need, but its definitely not enough to fully charge a set of batteries. Its thatlast bit, and it can take many hours. But thats what makes a set of batteries last longer, is to have a full charge on them.

As the batteries get more charge on them, their voltage increases. The less the difference between the battery voltage and the charger voltage, the less current flows to the battery, and the slower it charges.

You may have started at 60% charge - down at the low end I'm not sure how accurate that charge % is on the charger. It probably just goes by voltage which is not a good measure of charge unless the batteries have been sitting for several hours neither charging nor discharging.