Genuine request for help!

[littlemac]

Hi - I have at my disposal 45 or so LiFePO4 batteries (Valence U27-12XP), which are part of my brother's estate. He also left some solar panels of different types, and a load of cables and so on, also 3 or 4 ultra capacitors. Some of this may be of interest to people here, and I am happy to sell them, but more importantly I do not know much about any of this, how to test, charge or dispose safely of such things, and am looking for advice and help in understanding what exactly I've got on my hands.

These look a lot like the pics I've seen of earlier Valence Tech stuff, but also some later ones as well. I've too many to show them all, and I've got a couple of weeks to organise a solution for them... Testing with a multimeter shows most are holding over 12v, but some are far lower. I am attempting to charge them if they are below 12v using a charger with a Lithium profile, but it only gets to about 12v or just over. Many are flashing green, some are flashing red, one or two are not flashing at all.

They are in the Yeovil area, Somerset, and I'd really appreciate some guidance (visits welcome) from you experts! In the mean time, I'm reading, reading, and re-reading again...

 

[sunshine_eggo]

I recently resurrected the smaller 40Ah XP series U1-12MBS. Dead LED, and it was sitting at 0.8V. I used a constant voltage power supply to force output voltage/current if the battery would accept it.

Does the charger also have the option to work as a constant voltage power supply?
Have you let them attached to the charger for at least 30 minutes?

Flashing green should measure an acceptable voltage - likely 12-13.4V, and should be in a working state.

Short term: I would simply get them above 12.8V to get them out of the danger zone.

No idea about the ultra caps.

 

[littlemac]

Thanks for that - as luck would have it I do have a few power supply units that are used as bench test kit. I'll hook one up and see what happens, as I do believe that they could be resurrected. Currently I boost for a few hours using a standard car charger, then swap to a trickle charger with the lithium profile. However, I think it is stopping around 12v and not taking it much beyond. Unless my meter is fibbing... and it has been known

 

[DIYrich]

However, I think it is stopping around 12v and not taking it much beyond.

Depending upon the battery chemistry, that seems low.

 

[Hedges]

Given the cables coming from those batteries, I suspect external BMS. There is mention of connecting to build larger packs.
But, also something about data cable which suggests internal BMS.

Robot or human?

U-Charge XP Lithium Ion Battery Series | Lithion Battery Inc.

The U-Charge XP lithium ion battery series is a family of 12V, 18V, 24V and 36V lithium battery modules.

www.lithionbattery.com

Probably each has a BMS, but also linkage for data and perhaps active balancing.
I think that data cable would be useful to check state of each, maybe reset if in protection?

"With data cable it will wake up batteries and allow you to monitor all battery stats like SOC, Voltage, Temperature, Individual cell voltage, cycle count, and much more."

 

[littlemac]

Thanks for that - I've been doing some digging around in strange corners of the internet and it seems the old Valence diagnostic software is still available. I'll need to create a USB lead to connect to the Tyco's but that should be ok, and then I can run the diagnostics (hopefully) from there.

I believe even the older Valences had a basic BMS on board, but not sufficient to manage as an array, only to keep track of the internals on that battery.

I ran the charger overnight, and it settled into a comforting green light around 13.5v, which seems much more like what they should be.

 

[littlemac]

Not sure if this is of interest now, but I've worked through every module, and got the low down on each, using the Valence software. Some of them are pretty much no good, as far as I can see, but there are perhaps 35 that are good still, despite the age. Mostly these are version 1, or v1 with the Tyco Amp connector (call them version 1.5?) The version 2 batteries I've got here are all charged to 99% and either have a battery flag showing red (under 2.3V w/ Chg Curr), or the cell spread is too high after that charge - perhaps need time to settle down (on that particular module, the balance is showing 'active' and the cell voltage values have a blue background). I've not completed charging the rest, and SoC is currently sitting around 35-40% for most of these. All but one has a green light and with a few exceptions the cycle count is well below 100.

How important is the cell min (mV) reading?

I'll finish charging as best I can, and put together a spreadsheet showing the status on each one. I'd welcome any comments on what you think could be done with these, but also any specifics on what to do with those where there is a red LED... are these beyond hope? How the heck do you dispose of these modules safely...?