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Reviving flooded deep cycles

wopachop
Explorer
Explorer
Wanted to share this attempt at getting a little more use out of this battery. We accidentally drained it all the way down to 0.000v. Ive never seen my charger display that before. Even using Pb mode and calling it a 1 cell battery it still would not begin the charge process. 
The battery tender charger as well didnt want to begin the charge. We got jumper cables and jumped the battery for a few seconds and then the battery tender kicked in. Its the 5a version of battery tender brand.
I had 2 questions that the smart fellas here might be able to shed some light on. Im assuming the battery is dead, because one of the kids left the 12v LED lights on. I had an adjustable voltage regulator hooked up to (2) of the 8v batteries and the regulator knocks it down to 12v. 
What i found strange is the battery with the positive lead was low, while the battery with the negative lead was completely dead to 0.0v. 
1. Why did the negative battery die, instead of both batteries dying? The battery that died was 1 year old. While the battery that lived has got to be over 10 years old.
2. Second question is when i hook up my fancy charger to some of the batteries, the voltage will flash, then disappear. Its like it loses and regains connection. Sometimes if i catch it at the right time i can get the charge to start. But usually it tells me "connection error." What is going on inside to batteries to make the connection come and go like that? Pretending my alligator clips and nice and tight on clean metal. Only some of the batteries acted this way. My fancy charger didnt like those batteries. But the 5a battery tender has no problem recognizing them and charging away.



25 REPLIES 25

grizzzman
Explorer
Explorer
wopachop wrote:
Does it turn open circuit because of a mechanical failure? Or does the chemistry flip back and forth?

It's strange how my charger voltage display will turn on and off, just as if the battery was a switch and turning on and off. Just seems like a mechanical failure would be permanent. So I dont think it's that.


Then you have never seen an internal strap connection "lift off" (go open) then cool and reconnect then. It happens.
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philh
Explorer II
Explorer II
I built a charging circuit that would at least partially revive a lead acid battery. Pitched it with a whole bunch of other junk. Simple circuit, large cap, bridge and power switch

wopachop
Explorer
Explorer
Never seen this before. Look at those youngsters!!
https://www.youtube.com/watch?v=fpKQOvlDr-s

wopachop
Explorer
Explorer
11pm almost forget to take my fancy charger inside!! Happened the other night. Had to check security cams to determine morning dew. Walk me out, in the morning dew, my honey.

wopachop
Explorer
Explorer

wopachop
Explorer
Explorer

wopachop
Explorer
Explorer
I can go out there and change the charge voltage right now. Its on a golf cart i have it outside in the middle of nowhere in case the sucker burst into flames.

In order to do a 2.7v charge i have to trick the charger. Call the 4s battery a 5s and then reduce the voltage. It wont let me go up to 2.7.

time2roll
Nomad
Nomad
If you want to attempt to revive a battery best I can say is to give it an equalization charge at 2.5 to 2.7 volts per cell. Keep going as long as the specific gravity is increasing in all cells until you reach full charge. MEX might have better details.

MEXICOWANDERER
Explorer
Explorer
32 volts was the standard USA rural electrification standard in the US.
Many commercial marine vessels are 32 volt 16-cell systems.
(4) 4 cell batteries. 37.5 voltage regulator bulk setting.

wopachop
Explorer
Explorer
Decided to use my SG tool. Im a weirdo and didnt want to use it on anything but my brand new costco 6v. I dont want some old crappy batteries getting it dirty inside. I dont know the history of them old trojans. Then remembered this black battery was brand new and im the only one who has touched it. So i know besides at the factory no dirty water or dust has gotten inside.

Hard to see but its not even registering at the lowest 1.100 mark yet. That was interesting to see. Shows how much SG tells you. I took the reading while the battery was absorbing 12a at 2.45v per cell.



wopachop
Explorer
Explorer
Im still confused to it. I basically had 1 giant battery with 8 cells in series. Yet the 4 cells on the black battery drained to zero. While the 4 cells on the 10 year old trojan battery maintained voltage. Super super low at 7v but not completely down to zero volts like the other battery.

Maybe what im failing to comprehend is that the 8v battery drained to 7v was also completely dead. Maybe there isnt much difference between 0 volts and 7v when you are talking about 8v batteries?

Hope that makes sense.

wa8yxm
Explorer III
Explorer III
Never seen 8 volt batteries before

Why did one die and not the other.
Very unusual for two batteries even if they are "Twins" to be identical
one cell will always die first.
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wopachop
Explorer
Explorer
Would it be a mistake to go straight into equalization charge voltage?
I started with a 5a charge for maybe 5 hours. Then it was a 7a charge today for a few hours.

Now im using my nice charger. Its taking 12a to maintain 2.45v per cell. I have it set to a 20a charge. But currently its taking 12a.

Would it be better to try and shake the plates clean using a 2.7v per cell charge?

wopachop
Explorer
Explorer
Does it turn open circuit because of a mechanical failure? Or does the chemistry flip back and forth?

It's strange how my charger voltage display will turn on and off, just as if the battery was a switch and turning on and off. Just seems like a mechanical failure would be permanent. So I dont think it's that.