bertworks(dan@jhm)

i have an odyssey pc680mjt and have loved it for about 6 months now with absolutely no problems. just went to fallon, nevada for about 3 weeks and forgot to disconnect my negative and when i got back my car was totally dead. went to charge it up and drive it for about 20 minutes but when i turned it off my car still wouldnt start.

do you guys think that battery is totally shot? any suggestions would be helpful.

thanks

Milpitas2.7T

shouldn't be,

ChucktownS4

sounds like the battery yes, this cold weather is hard on old batterys

bertworks(dan@jhm)

even if the battery is only 6 months old?

FixedWing

<center><img src="http://www.accumate.com/pro/12V-7A%20Odyssey_for_web.jpg"></center><p>
So long as they have enough of a charge in them then the car alternator will charge them just fine. But if you kill one completely then it won't and nor will an ordinary charger charge it.

When I killed mine (left an interior light on overnight) I initially had to jump the car to a lead acid battery for about 20 seconds to get the car open. When I jumped it there was quite a spark indicating it was taking a good load and I actually thought it might burn out the thin wire I was using. Then I charged it with a battery charger specifically indended for AGM batteries. It took the charge and was fine again.

For the future, I suggest you get one of these. There are a few different ones made. Anytime you will leave the car for more than a week you really must hook it up. If you leave it outside (airport long-term parking for example) then get a solar charger panel. They are very cheap.

You are on your own as far as if anything nasty happens to your car, but what I'd do is either hook it up to one of those monster chargers that force a high amperage in to the battery or alternatively, jump it to a fully charged lead-acid battery. One of the advantages of an AGM battery is that they can take and give an unlimited load. So they will take whatever the charger can put in and they will suck the lead acid battery dry (so use big cables). But you must be really careful that the voltage is not above 15.1 VDC (that figure is from memory so could be off a little and you might want to check it). Anything above that figure will kill the AGM. Some of the big chargers do use a high voltage so be careful.

Personally, I'd pull the AGM out of the car to do whatever you decide to do to it.

Stephen<ul><li><a href="http://www.accumate.com/pro/12v-7a-odyssey.htm">AccuMate PRO 12V 7A-S Odyssey</a></li></ul>

ChucktownS4

with a multimeter for draw on resistance pulling one fuse at a time then checking the meter with the ign switched off" pulling 0.05 ohms or whatever" "hook the meter up with one terminal on the battery and the other on the loose neg batt cable" or have a shop check it out, if you recently installed some eletronics check there first

ChucktownS4

if its a special battery make sure you charge it correctly like posted above first though

bertworks(dan@jhm)

so what your saying is that if even though i killed my battery i could still hook up a slow rate charger and charge it for about 12 hours and still get it going?

FixedWing

I'm saying that a slow rate charger will *not* work until you have at least got a certain charge level in to the battery. Only slow chargers specifically designed for AGM are able to charge an AGM battery from completely dead.

So you either need to jump it to a fully charged lead acid battery for a little while or put it on a high powered bulk charger for a little while. Read my first email again for details.

Stephen