So I bought an Ego-Kit,the 3400W one. Worst Idea Ever. HELP!

[tuu]

You don't have to take the welds off. First double check the "bad" cell group voltage with your meter. Then to charge/discharge just use the alligator clips to clamp on where the sense leads are soldered on for the particular parallel cell group. Suggest unplug your sense leads from the circuit board when doing so in case there is a fault. Also test the sense leads back to the circuit board with a meter to help troubleshoot problem.

Thanks for the heads up, this sounds like a good way to start. I do have one issue, the charger I bought says up to 6 cells max, mine are rows of 7, is this a problem? If not, what charger settings do you guys suggest I use to start with to revive the first set of 7 cells that currently read 0.1V? Thanks!

 

[amberwolf]

THat's 6 *series* cells, yours are 7 *parallel* cells.

To use your charger to charge a single row of those parallel cells, you will only use the main negative and positive wires, and if necessary (probably not) the very bottom wire of the balance.

The main negative wire goes on the negative side of the cell group you want to recharge, and the positive wire on the positive side.

Then you set the charger for "1s" "li-ion" or "li-po", will probably say it's for "3.7v". If it has a charge rate setting (amps) I'd set the very lowest setting it can go to.



But if those are really at 0v, you should not charge them, you should replace the row. Even if they recover they probably will not be the same as they had been, and there is a risk of fire for cells that are below their minimum voltage, especially since you don't know *why* they are drained down. If they are at 0V because there is one that is internally shorted, then recharging them could either directly overheat that cell, or it could heat that one a bit while charging the rest, and then it could quickly drain all that charge out of the others, heating it further. What happens after that depends on what's wrong inside it and how hot it actually gets. :/

It's also possible nothing will happen, but the risk is there.

That's the reason BMSes in general won't allow recharge after a cell drops below a certain point.

Now, if the cells are not actually at 0V, and are just a bit below 3v, and the BMS has cutoff to protect them, then you could probably safely recharge them.

 

[Jon NCal]

Normally, an RC charger is smart enough not to let you charge a 0V lithium cell. You might have to research what mode or how to boost it to start charging. Or try to find if there was a BMS failure or what caused it to drain to 0V first.

 

[emcee]

Get you meter and figure out with cells are dead.


Here is a picture of an 18650 so you can figure out which colour is positive and which is negative

 

[tuu]

Get you meter and figure out with cells are dead.


Here is a picture of an 18650 so you can figure out which colour is positive and which is negative

Thanks for the heads up. The cells are connected in parallel so I am unsure how to test cell to cell. I have the charger connected to one set of the bad cells and I am at about 1.0v after and 75mins and still charging. I am using a digital infrared thermometer to watch the individual cell temps as I charge. (just in case)

I keep you guys updated, it will probably be a while to charge both dead packs......

 

[www.recumbents.com]

did you check to make sure that the balance wire that is in the middle of the two dead groups has continuity to the battery buss bar? You can do that with the ohms or diode check setting on your VOM.

 

[emcee]

Get you meter and figure out with cells are dead.


Here is a picture of an 18650 so you can figure out which colour is positive and which is negative

Thanks for the heads up. The cells are connected in parallel so I am unsure how to test cell to cell. I have the charger connected to one set of the bad cells and I am at about 1.0v after and 75mins and still charging. I am using a digital infrared thermometer to watch the individual cell temps as I charge. (just in case)

I keep you guys updated, it will probably be a while to charge both dead packs......

Just pretend that the welded strips are not there, and measure from one end of the cell to the other. If it much below samsungs stated minimum voltage of 2.5 volts, consider replacing the cells. If they still have some energy left then try to charge them up. You will have to keep a close eye on the battery, there is a reason the cells were discharged. Possibly a BMS issue. Consider disonnecting it when storing it for longer periods.

 

[mushymelon]

If your a visual guy maybe this will help.
Each group of 7 cells is now 1 big cell and should read on your multimeter between 0v - 4.2v
you definitely want to check them with you multi meter before charging if you haven't already.



View attachment 3


Heres some google images for worst idea ever



View attachment 1

 

[tuu]

If your a visual guy maybe this will help.
Each group of 7 cells is now 1 big cell and should read on your multimeter between 0v - 4.2v
you definitely want to check them with you multi meter before charging if you haven't already.

I feel your attachment with the two guys in the Zebra suit getting raped by the lions really helped bring your point home. :lol:

Seriously though, I found every set of 7 cells to be about 4.0v aside from 2 sets. Those 2 sets came in at 0.1V are featured below with a mild form of herpes.



I am currently trying to revive these 2 sets , so far each is at 1.8v. Worst case scenario, if I can't save the cells, has anybody here successfully dissembled and reassembled a cell case like this before?

 

[mushymelon]

It didn't seem clear if you tested/charged the cells directly or just through the small leads, but you got it.

Rebuilding this pack is very doable with the right gear, battery welder, nickel strip and a soldering iron. First i would want to know why 2 groups went dead. 1 group would be rare 1 cells goes bad takes out the rest ok maybe but 2 groups very strange for new quality cells.

I could make you up a 14s 1p pack you could hook up the balance leads to the bms and see if it drains the 2 groups.

 

[waynebergman]

I would rather face that monkey with the gun then try to take that pack apart. I had bad luck with trying to marry up two partial packs into one good one and had the pack burst into thermal run away. I think that is the correct term for it? It was like 90 some roman candles going off and it lasted for over 10 minutes.

 

[mushymelon]

New cells with new cells will be ok no Monkey business

 

[izeman]

just to repeat: whatever tuu is doing now is most probably just to do trouble case reason analysis. i would not recommend using the pack, even if the batteries will be charged afterwards, as they for sure have some suffered some (severe?) damage.
as stated before: please take off the balance wire's plug from the BMS while charging. in case the BMS is the problem it will make fact finding harder if still connected.
so next step: once you manage to charge those 2 cell groups to 4v, let it sit for a day or two, observing the state of charge (SOC). if it holds charge, reconnect the balance wire plug and go on monitoring voltage. if it drops than you can be almost 100% sure that you have a BMS hardware issue, and swapping the cells will just burn more money and NOT solve the problem.

 

[tuu]

I would rather face that monkey with the gun then try to take that pack apart.

so next step: once you manage to charge those 2 cell groups to 4v, let it sit for a day or two, observing the state of charge (SOC). if it holds charge, reconnect the balance wire plug and go on monitoring voltage. if it drops than you can be almost 100% sure that you have a BMS hardware issue, and swapping the cells will just burn more money and NOT solve the problem.

I charged both groups (balance wire, BMS, disconnected) for 4 hours each yesterday, highest either group got was 1.8v and by the next morning they were both down to 0.8v. Seems the cells are the issue since they are draining without being connected to the BMS. Thoughts?

 

[emcee]

I would rather face that monkey with the gun then try to take that pack apart.

so next step: once you manage to charge those 2 cell groups to 4v, let it sit for a day or two, observing the state of charge (SOC). if it holds charge, reconnect the balance wire plug and go on monitoring voltage. if it drops than you can be almost 100% sure that you have a BMS hardware issue, and swapping the cells will just burn more money and NOT solve the problem.

I charged both groups (balance wire, BMS, disconnected) for 4 hours each yesterday, highest either group got was 1.8v and by the next morning they were both down to 0.8v. Seems the cells are the issue since they are draining without being connected to the BMS. Thoughts?

Not surprising that they didn't hold an sort of charge. Who knows how long they sat at 0v. What ever caused the initial discharge remains to be seen though. Bad bms, bad spot weld, faulty cells? Looks like you are in the market for some new cells. I think it goes without saying but get the same cells that are in the rest of the pack.

Maybe canvas the forum for someone who can spot weld them in the configuration you need.

Or if you don't want to deal with it. Sell it for salvage and buy a brand new one. EM3EV or grin have some good pack that would work nicely. There are lots of other vendors, but I have no experience with them.

 

[tuu]

did you check to make sure that the balance wire that is in the middle of the two dead groups has continuity to the battery buss bar? You can do that with the ohms or diode check setting on your VOM.

I did, upon your request, the balance wire does have continuity to the buss bar.

 

[Ykick]

Last thing you wanna do is go looking for replacement cells until you've determined balance circuitry is not the reason for the duff cells. I find it highly unlikely cells of that quality simply died on their own without some help? Particularly more than one group? Astronomical odds IMO.

For starters check for shorted balance bleed transistors. When shorted they can take cells to 0V even if the rest of BMS/PCM is shutdown.

 

[izeman]

so next step: once you manage to charge those 2 cell groups to 4v, let it sit for a day or two, observing the state of charge (SOC). if it holds charge, reconnect the balance wire plug and go on monitoring voltage. if it drops than you can be almost 100% sure that you have a BMS hardware issue, and swapping the cells will just burn more money and NOT solve the problem.

I charged both groups (balance wire, BMS, disconnected) for 4 hours each yesterday, highest either group got was 1.8v and by the next morning they were both down to 0.8v. Seems the cells are the issue since they are draining without being connected to the BMS. Thoughts?

imho correct. this confirms that the cells ARE DEAD. unfortunately it says nothing about the BMS yet. i would connect just ONE single cell to the suspected BMS connection and see what it does. but i have all the equipment at home to do the test. single cells, soldering iron, connectors, battery holders, all that stuff.
it's hard to give some advise as i don't know how far you're willing to go. and even if the BMS is ok: how are you gonna swap the dead batteries? are you able and willing to do it?

 

[tuu]

it's hard to give some advise as i don't know how far you're willing to go. and even if the BMS is ok: how are you gonna swap the dead batteries? are you able and willing to do it?

I think this is as far as I am willing to go into the battery myself. A professional should take over from this point. Now that we know exactly what is wrong with it; can anybody recommend a US shop to repair this battery pack?

 

[izeman]

i would make a new thread asking for battery repair help. there are several guys that can weld a complete pack and could probably help.

 

[emcee]

Ensure you update your location in your user info.

There might be someone fairly local that can assist you welding in two new parallel groups.

 

[tuu]

i would make a new thread asking for battery repair help. there are several guys that can weld a complete pack and could probably help.

done: https://endless-sphere.com/forums/viewtopic.php?f=3&t=75921

Ensure you update your location in your user info.

There might be someone fairly local that can assist you welding in two new parallel groups.

and done.

Thanks a ton guys. It has been super helpful to nail the issue down to exact parts that need to be replaced and tested.

Side note, izeman, your custom kona midrive is amazing, that is a lot of time and hard work, wow. It looks better than any home built I have ever seen and could even pass for a production Kona. Kudos sir.

 

[izeman]

Side note, izeman, your custom kona midrive is amazing, that is a lot of time and hard work, wow. It looks better than any home built I have ever seen and could even pass for a production Kona. Kudos sir.

thank you. i tried to make it look as "production like" as possible. no visible wires, no duct tape ... i was asked several time where this bike could be bought. the best compliments you can get.

 

[tuu]

Just a heads up everybody who has been following my Ego-Kit saga, I have had ZERO luck finding someone to repair this battery. If anybody has any options for repair please chime in. (I am very surprised that with all of the growth in the ebike industry there does not seem to be anybody doing pack repairs in the USA.)

Thanks in advance.... your humble ebiker wannabe......

 

[Harold in CR]

Posting your location as USA does not help you any. Suppose you are in Oregon. How does a person in Louisiana help you ??

At LEAST name the town or city you live in, then, you might get results.