Ping 36 v 10 ah battery not charging

[passpato]

My friends 36v 10 a/h Ping battery will not charge. It is about 5 years old now. I thinkthe BMS is stopping the current flow. I have an identical battery and I am able to test things by swapping around and/or testing with a multimeter. The Charger works ok on the other battery so I'm ruling that out. I have tested connections up to the battery and they are ok.
There is no output from the battery however . I can measure a Voltage of 28 volts from the charging input wires into the BMS and the output wires from the battery has the same voltage but when I touch the output wires together there is no spark. I think the BMS has cut output power and voltage is too low to charge but I don't really know what Im doing.
Can anyone tell me whats going on ? Is it a dead Cell ? Can I recover it somehow?

 

[e-beach]

Ping LiFePO4 Battery?

28v on a 36v battery.....2.33v per cell? That is dead. After 5 years this battery has probably passed it's lifespan.

How exposed it the BMS? Can you take clear pictures of both sides so we can see which one you have?

Sounds like the battery hasn't been charging. 28v out of your charger?.....for 36v battery? Are you metering the battery and not the charger?

Edit: What kind of charger is it? Can you open it up to test the output wires on the PC board while it is charging so you can really see what the charger is doing? Or, can you put an RC watt meter in-line so to test volts, watts and amps of your charger

On the battery, one way to test is like this......

Meter the individual cell voltages through your balancing wires so we can see what they are. Start with the black ground balance wire and the white one next to it. Measure the voltage. Then move the up the line so you are probing two white wires. The one next to the black ground balance wire and next white wire. Keep moving up the line of white wires until you measure all the cells.

Write down the results of each cell and post them like this:
1: x.xxv
2: x.xxv
3: x.xxv
Etc.

Then, if you so choose to do so, charge straight to the battery and avoid the bms all together. Be cautious when you do this not to over charge or short your battery. Once it charges to 43v test the individual cells again and re-post the results. Then connect it to the BMS and your bike and see if you back to normal.

Once we know that your cells are healthy then we can eliminate the cells and know it is the BMS.

 

[999zip999]

Put voltmeter on charger. Charger need to put out 43volts check first and post.
Check all cell voltages and list like e-beach posted, post here.
1.
2.


12.
Don't bypass bms till you answer all these questions
Never charge one single cell over 3.65 volt. If you bypass the bms a cell can over charge above 3.65 volt and make Fire. Really ping can charge to 3.75volt ut after 3.5 volt there is little capacity or room for more charge.3.4volt 87% annd 3.6v is a lot different. 3.5volt is 90% full and will race to higher voltage is very fast as it is full. At this point will cause damage. You can cause fire.

 

[dogman dan]

I would tend to think that at 5 years old, some cells inside the pack have died. If any are puffing up, then that is certainly the case. Same if you smelled sweet stink from the battery at any time in the last few years.

You could investigate further, checking the voltage of each cell. Do that more for your own edification than aiming to get the battery going. Unwrap and examine the bms, it could have obvious problem with the fet that the battery charges through. The fet is an electronic switch, that looks like a small black square, about half inch size.

 

[passpato]

I emailed Ping and they are helping me. Its great to have support but it takes 24hours to get replies because of time difference between uk and China.
I think the battery is a Ping 3.2 . The ebike was left for over 6 months and the first 4 cell packs run the BMS (signalab).This has taken these to below 2.5v Ping have told me to manually charge one cell pack at a time. This opened the Low Voltage Protection and I was able to use the Ping Charger. The first 4 cell packs are still only holding 3.3v at rest. I can't get past that by manually charging the low cells. The BMS can not balance all cells at this low voltage. I am waiting to hear from Ping again tomorrow. I may be able to replace the weak cells.
Pings Service has been amazing throughout my ownership of these batteries and I wouldn't hesitate to buy again from them.
My own Ping 10a/h still holds over 9 a/h at 5 years old. It has been better looked after than the one giving trouble.

 

[999zip999]

Batteries are made to be used and forgetting them is not the best.

 

[e-beach]

Yes you may have some dead cells. Putting new cells into a pack with 5 year old batteries isn't a good idea either.

How long did you leave the charger on the battery after you got the low cells charged enough to use your ping charger. Did you leave the charger on the battery pack for 24 hours? 48 hours?

 

[passpato]

Ping explained the charging period for these cells. They raise to 3.2 quickly and remain around there for a long time rising slowly. After they reach 3.5 they rise quickly to 3.9 . This can take 10 hours at 1 amp for each cell. After charging each of my 4 cells for 6 or 7 hours from the 3.2 level and cutting the amperage back to reach 3.9 it looks like the battery will recover to a usable condition even if capacity is set by the weakest cell.

 

[passpato]

I have charged the first 4 cells at 39v as directed by Ping. I charged untill the current fell back on my power supply. It took a long time to charge each of these cells. I think they have a high resistance to charge. After resting these cells dropped back to around 3.3 v. Ping told me to use their charger now. The Charger can not bring these cells up and goes off when the other cells light their leds. Is there some way I can get these 4 cells to hold a higher charge ? My emails with Ping are going around in circles. They want me to change the bms now because the charger is not cycling as it should at the end of charge. I want to see these cells recover first. Is my battery usable as it is with these 4 at 3.3 and the rest over 3.5 ?

 

[dogman dan]

Dude, at 5 years, you just exceeded my personal best lifetime for a ping battery by 1 1/2 years. It's done. Balancing it will help, but you are never going to put the toothpaste back in the tube.

Those cells that only hold 3.3v, will never hold more than 3.3v again. And the rest will be behaving similar soon. Buy yourself a new battery for x mas.

 

[e-beach]

Yep, like Dogman sez........If you are applying a voltage higher then what the cells are at rest, and the cells don't take a charge, the cells have exhausted their useful life. Using you battery with unbalanced cells will risk the chance of over discharging the bad cells killing them faster. Not to mention reduced range if the BMS cuts power when the cells trigger the low voltage cutoff.

But, if you are really in love with your old batteries..........

....and you want to balance the other cells down to 3.3v and have a battery pack with less then 50% of it's intended capacity then you can do that as well.
Your BMS might be able to balance down to 3.3v, but that could take a long time.

So you could make some sort of a light-bulb-and-or-resistor device and manually drain the "hotter" cells down to 3.3v.

Or you could purchase a balance charger that will let you can set to charge and balance at 3.3v per cell.

In any case, with all you cells at 3.3v you wont be going very far before the pack hits LVC

Or you can hunt around and see if someone will sell you an old ping battery and take the chance that you will find enough usable cells to splice them into your old battery pack all-the-while knowing it wont have near the capacity of a new battery pack.

The best choice is to just get a new battery and when it is not in use for a long time disconnect the BMS so not to drain the cells down enough to ruin them.

 

[passpato]

Thanks Guys.
it looks like this battery is near end of life.Or does anyone have a donor battery in the uk and can help us? Worth a try I suppose. My friend doesn't need a full charge 6 or 7 a/h would do .
One last question. Ping tell me to charge at 3.8 -3.9 v . All the single cell chargers I can find are 4.2v . Is there a reason Ping is lower ? Is it a lower C rate ?

Regards and many thanks for all of your replies

 

[Gregory]

Its a different chemistry.

Ping cells are LiFePO4 max charge around 3.65V (some manufactures may spec to 3.8V or higher).

4.2V is for LiCo and more recent chemistries, many 18650's etc.

Others again are 4.35V.

 

[passpato]

Can anyone recommend an economy single cell Charger for my Pings ? I'm in the Uk so 240v 50 hz . Or I have a PSU from a Computer to power a buck.

 

[dogman dan]

Imax B6 or similar cheap 50w RC charger will do great for single cell charging lifepo4. It has settings for all chemistries, lipo, lifepo4, NiCad, lead, etc. they power off a 12v power supply.

 

[999zip999]

3.6v is fully charged. 3.9v is for the bms to bleed the cells down to 3.6v. never charge one above 3.9v as 4.0 is to high. New battery time. Cells are 12.50 each and you need 3 cells 5ah each for 15ah. plus shipping. So 12.50 x 3 = 37.00 x 4 = 154 usd. plus shipping.

 

[passpato]

Ping cells are $9.30 or £6.17 each. Its 10 A/H so 9.30 x 2 = 18.60 18.60 x4 = $ 74.40 or £49.36 + shipping but I also need a bms.

 

[999zip999]

Ok . But putting money in a 5 year old battery ? Thanks for the update.

 

[passpato]

It turns out the sells are ok. They are very difficult to squeeze that last bit of charge into them. I used an imax in the end. Ping is now sending a new bms as the old signalab will not allow charging. Does anyone know what goes wrong with this curcuit ? The fet seems to be working. I wonder if it can be repaired .

 

[e-beach]

It turns out the sells are ok. They are very difficult to squeeze that last bit of charge into them. I used an imax in the end. Ping is now sending a new bms as the old signalab will not allow charging. Does anyone know what goes wrong with this curcuit ? The fet seems to be working. I wonder if it can be repaired .

What testing have you done with the individual cells leads you to the conclusion that they are ok?

Post pictures of you BMS. Make sure they are clear. We need to see both sides. Our best guy at things like BMS repair hasn't posted in a while, but maybe we can figure it out anyway....