I've had car batteries discharged to 0 volts. Standard cheap chargers won't even try to charge them, so they have to be bootstrapped with a real power supply before the charger will take over.
They recovered fine, but they were discharged for less than a day. Maybe longer term zero volts would be fatal.
Sulfated batteries tend to rise in voltage, not fall to nothing.
The OP is either charging with reverse parity, or has a number of shorted cells. I have come across one or 2 shorted cell but no more.
If active material is moving between plated, sometimes a hefty thump can remove a short.
rote:
e and it was down to zip voltage. I put a power supply on it and ran up th e voltage until the current was at 2 amps. As I watched the battery voltag e dropped and the current rose! I double checked all the polarities and it 's wired up right and the ground on the vehicle is disconnected.
rose I dialed the voltage back, lather, rinse, repeat. It is now down to
2.5 volts and the current is still slowly rising. I've never seen this bef ore and I've never read about anything like this. Any ideas??? 9V terminal voltage to you.Right , there's a time element involved, and a lot less of a discharge to 0 V will do it. You'll find the better automotive inverters have a low batter y cutout, and it should be programmed for 1.75V/cell.
Don't buy cheap reconditioned lorry batteries unless you have access to fit young men to carry them from the nearest road to the cliff-top trig point and replace them every couple of days.
Otherwise, nothing much helps if you're going to flatten them, and you will flatten them because no-one's going to swap the batteries after a long days work when the pubs are open.
Oh yes - don't check for hydrogen with a match having forgotten about the oxygen. Sulphuric acid vapour irritates and loud noises cause temporary deafness along with visits from management. (Luckily this was just a small battery.)
Cheers
I've learned something from this exercise. Costco batteries are not the va lue they used to be. They used to have a good price and a great warranty. Now the price is as high as anyone else, maybe higher, and the warranty is no better or maybe worse. A battery for my pickup was over $90 even after subtracting the core charge and only a 42 month warranty!
Next time I'll shop it around. I'm sure I can do better.
On Wednesday, May 1, 2019 at 8:07:51 PM UTC-4, snipped-for-privacy@gmail.com wrote :
value they used to be. They used to have a good price and a great warranty . Now the price is as high as anyone else, maybe higher, and the warranty is no better or maybe worse. A battery for my pickup was over $90 even aft er subtracting the core charge and only a 42 month warranty!
I think for lead acid batteries, you can judge the value by comparing dolla rs/pound.
mIdk where you are, but $90 for a battery for a pickup sounds very reasonable. That's not much more than a fill up with gas and unlike that you only have to do it at long intervals.
Wow! Gas is expensive where you live!
ble. That's not much more than a fill up with gas and unlike that you only have to do it at long intervals.
The last battery I bought at Costco was more like $60, but I may be mistake n. Costco had a peak of value where it was around $50-$60 for a battery wi th a 9 year warranty... yes, 9 years prorated after the first 3. I actuall y replaced one in the fourth year and only paid $15 or something like that. The last two I've bought there have gotten more expensive and shorter war ranties.
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