Bought Valence batteries

After seeing Will's video raving about used Valence batteries I bought two U1-12RT 40amp. I just received them and both show o.o volts. Does this mean they are defective and I bought a couple of boat anchors or is there something I need to do to them to get them charged? I tried hooking my charger to them, but it just acts like nothing is connected. The data cables were cut off both of them if that means anything.
Completely ignorant novice here so appreciate any help you can give.

Thanks,

Graham

From the Valence manual:

8.4 No LED Indication: Severely Over Discharged If the LED indictor is not blinking and the battery voltage is below 7V: • Charge with 1A until the lowest cell voltage reaches 2.7V and the LED blinks green. At this point, use a normal charger (<20A) to charge the battery normally. (see NOTICE below) • The individual cell voltages can be viewed with the RT Monitoring and Diagnostic Kit (Valence part number 1004236).

NOTICE: If the battery was charged at a higher current than 1A and the lowest cell bank do not reach 2.45V within one minute, the battery will lock up and flash the slow red flashing state (Red LED on for 2 sec. then off for 3 sec.). Once in this state the battery must be allowed to sit open circuit for approx. 12 hours or longer depending on battery type (U1 to U27) and the battery voltage. The overall battery voltage must fall below 5.35V. This is the point when the LED will change from slow flashing red to fast flashing yellow or no LED at all, before it can be charged with 1A again.


I bought 2 and one of them was showing a reading of less than 4 volts. And the LED was not blinking. I used a 3 amp wall wart (1 amp would have been better) and brought it back to life.

Thanks for the link to the manual and suggestions. I have a Viking 4 amp and an old Dart Drug 6 amp charger. I decided to try a small 10 watt solar charger since it was sunny and I figured it would be closer to the the 1 amp charge. Since the Valence had 0 volts the solar regulator was not activated. I hooked up an old lawn tractor battery in parallel with the Valence. This provided the 12V to activate the solar regulator and it started charging. The Valence yellow light started blinking. After a while the Valence read 4 volts. Tried it on the second battery, but it only came up to 0.4 volts. Ran out of sunshine so had to stop. Not sure if I should continue with the solar or give the Viking 4 amp charger a try. 4 volts may be enough to get the Viking to put out a charge, but I doubt 0.4 volts is enough. Next couple of days are supposed to be overcast so solar will have to wait.
Does hooking the lawn tractor battery in parallel with the Valence help limit the charge going to the Valence? I put the Valence first, then the LT battery. Pure guess on my part, but made sense in my mind.
Thanks for any suggestions and education on the physics at work.

Graham

How many amps do you think was going from your lawn tractor battery into the Valence battery?

At this point I would go ahead and try with your 4 amp charger. Keep an eye on the voltage. If the light turns green, then you should be good.

Are either one of your chargers made to charge LifePo4 batteries? Don't charge above 14.6 volts.

Since I had the solar charger attached, I assumed it would be trying to charge both the Valence and the lawn tractor battery which would reduce the amperage going to the Valence. If I understand your question, you are saying the lawn tractor battery was sending a charge to the Valence. Not sure how much the lawn tractor battery could put out. It is old and could not even start the tractor.

Neither charger is intended for lithium. The Viking can be set for AGM or gel and does display the voltage so I can watch the the voltage.

Does the Valence BMS regulate the incoming voltage?

The BMS doesn't regulate anything. Your charger regulates the voltage and the current going into the battery. The BMS protects the battery from over charge/discharge and balances the cells. The balancing is done at the top end of the charge. BTW, If your charger has a mode to recondition a battery don't use that. I believe yours does.

You really need to get to know the Valence battery. The best way, if you have not already done so, is to read through every page of the user guide I posted the link to. Hopefully you will be able to revive the batteries. Please update whatever the outcome is.