Pack testing ideas

[Rozla]

Hi all,

I have been splitting and testing failed 29v packs and harvesting cells from them for ebikes and such for my own personal use with great success.

However, I've recently acquired more than 200 of these packs through my work and my current testing methods for these batteries takes 16-24 hours per pack! It's great when I'm just testing a customers battery packs maybe one or two a week but I need something more substantial to keep up now.

I'm looking into a grid tie inverter that I can slot the batteries into discharge and then record the power discharged with a watt meter (I feel this isn't as wasteful as my discharge tester) don't get me wrong, the discharge tester is great when it's cold! But if I could charge other batteries in line for testing or pump it back into the grid it would be better.

Any advice on how to go about this?

Ross

 

[floydR]

If half a pack is 8s or less it could be handled with an (x8, x12) 30amp regenerative dischargeor an icharger 4010duo 40 amp regenerative discharge 70 amp charge might even do a 70a regenerative discharge i am not sure. the 4010duo is not cheap but would work well from all the reports i have seen. I have a x8. Just needs a large enough rechargable power source. This wouldn't put power back into the grid but fewer hassles no permits needed. daromer is the person to ask about the 4010duo he would know what it can and can't do. may be a perfect fit

later floyd

 

[Rozla]

Hi Floyd,

The packs are 7s 2p and 7s4p mostly so I will look into the 4010duo.

Once I've stripped a few of the packs I will be looking at making a proper powerwall from them. Currently have 6x92ah lead acid batteries powering my workshop/garage which are in need of replacing!

Looking forward to this project! I'm not the best with photos and videos etc but I'll try to remember to take some!

 

[floydR]

The x8, x12 are less expensive than the icharger 4010 But the 4010 is a much more capable tester/charger. If you break the packs down to just the cells a couple Opus or other 4 slot tester work good to test the cells.

Later floyd

 

[Rozla]

I quite like the opus testers, have a "portable rig" made up with 4 units on. Have ordered 4 more to make another test rig as I'm sure I will have a load more cells to test! These are the good cells I'm testing at the moment. But I want to be testing the entire packs where possible if they are salvageable before splitting. Hence the request for advice on different tester.

 

[floydR]

Laptop batteries? ebike batteries? Ninebot packs? There are many different syles of batteries. I know there are testers that can tell you information about the battery mainly for use with laptop batteries. If you can get access to the balance connector you could make adapters for a X8/X12/Cellmeter8,etc that will tell you the voltage of each series and total voltage of the battery. But that isn't testing the battery. The X8,X12,X6 can test and are good capacity testers. But if you want to see if a battery pack might be salvageable would be a good multi meter and a good IR tester, consistency with how you test, good battery in your tester ( my Digital multimeters are a harbor freight ones, a YR1030+ IR meter/tester)

later floyd

 

[Rozla]

Hi Floyd,

The packs are from 24v/7s mobility vehicles. The only access without breaking apart the pack is the 4 contacts on the base 2 negative and 2 positive. No access to balance wires or BMS.

Attached some photos of the ones that have failed my capacity testing (using a Titan Simple tester) and I've split. There are several variations in the design/cells.

The titan tester works well for capacity testing and gives a rough idea of how good the pack is.

I re-use the packs that pass capacity testing for our equipment and split the failed packs using the opus testers to ensure all the cells split are good for whatever I plan to do with them. (Mainly ebike packs and possibly a diy power wall.)

Ignore the rats nest of wiring, this was my primary use for the cells harvested from 4 of these packs. This pack was made from the 26650 cell packs badly stuck together with kapton tape, hot glue and fish paper it is 15ah and I did about 30 miles on a charge on pedal assist, and 10 miles on full speed. Needless to day I've improved my methods of pack building over the past year but I can't find any pictures of my latest battery.

I ideally want to be able to test 12v/24v/36v/48v with a later 96v battery planned for an electric motorcycle. I understand I will need a few different testers for these, just want to see what the general opinions are on different chargers and where to start.

My current experience is mainly with lead acid batteries and my own "messing about" into lithium batteries hence getting into the forums.

Ross

 

[floydR]

I ideally want to be able to test 12v/24v/36v

for 1s-4s any of the x series of icharger will work, for 24v 7s and 8s packs the x8 and the x12 will work. for 10s and 12s batteries only the x12 will work. The main thing is you need to be able to hookup the balance leads to the x series icharger.
later floyd

 

[Rozla]

So just to confirm, if I can get access to the balance leads, these testers will test the individual cell groups without having to split the pack?

 

[floydR]

the xseries of ichargers can tell you the (voltage, IR*, if doing a discharge capacity test the capacity**of each cell group. total voltage) ,mv between high cell and low cell.
* Dc IR not as precises Ac IR readings, **8s would have 8 cell voltages 7s would have 7 cell voltages a x12 can test up to 12s packs.
You can tell if the pack is healthy but to really test the pack almost have to break the pack apart. if more than 12s (x12), 8s (x8) I believe you need to break the pack into sections smaller than the 12s (x12) 8s (x8)
later floyd

 

[Maarten]

Love the simplicity of using screws next to the chargers to secure them.
Might give that a try

 

[Rozla]

Love the simplicity of using screws next to the chargers to secure them.
Might give that a try

Yeah... I was feeling creative after insulating my garage and found a use for the OSB. Literally took about 4 minutes to knock it up