lithium battery power on lifestand LSC?

[Burgerman]

The power supply is both a zero to 60V and zero to 50A power supply, and a 3 stage charger in the same body.

Its available thanks to shirley_hkg on this forum, and pretty cheap too. It is either stock, or comes with the fancy case you see there in those pictures that YOU fit.

So talk to shirley!

[jehan]

thanks… I will.

I saw one of your videos, that the fans are very noisy… will Most likely have to do what you did and get rid of the mesh as well as a larger fan.

does it stay noisy the whole time… Even when it is balance charging?

[Burgerman]

yes

[jehan]

Hi… I am Very excited to have finished building a 100aH back for the lifestand lsc wheelchair (Started this Monday) and followed pretty much the same process outlined in the 230 ah amy docan cells build

The pack is all built up with interconnect , balance and power cable.

I have verified that the voltage of all 8 cells are coming out of the JSt PA connector that goes into the PL8 balance port.

However, though the PL8 is able to see all eight cells, it is only able to see voltage from seven cells and sometimes six cells.

I am using a PL8 v2 on firmware 3.36 with bm preset for 2s to 8s 50 to 100ah .

Whatever I do I can't get the PL8 to see the voltage of cell 8. Wiring continuity has been crosschecked and all errors removed, which is verified from the voltage out of the jst pa connector end.

I haven't tried charging the pack, but when I try to monitor the pack, it detects all eight cells but only shows voltages for seven cells and then immediately diminishes to 5 cells, three cells , one cell and then shows a BAD CELL COUNT and stops monitoring.

I'm attaching some screenshots to help explain.

Is it some setting or firmware that I need to update?

[Burgerman]

3 questions that may help diagnose.

1. Did you properly SOLDER every connection or are you relying on crimped connectors?

2. What happens if you connect a load that draws around 1A across any/all of the balance wires, maybe a small bulb or resistor? Test each in turn. Because a bad connection at some place will show voltage and will not take a load. As it may be very high resistance. And the same with maybe 10 or 20A load across all 8 cells on the main cables.

3. What does it do on a different profile that does 8S?

4. What does it do when charging any other 8S pack?

Upload that preset, rename .zip so I can check I have not set something bad...

[Burgerman]

Wat do you have set here?

[Burgerman]

Other than this the only other thing that can cause this type of behavious is a noisy power supply. What are you using?
Test using a battery...

[jehan]

Dear John… How are you… Thank you for all the help as usual.

1. all the ring terminals for interconnect, power and balance cables are only crimped and no soldering. The only thing that is soldered is the D sub connections. I'm attaching a picture of the crimp

2. we have not tried any 1A load on any of the balance wires as we are only trying to monitor all the cells. I will try it and get back to you.

3. Your preset file had eight balance presets starting from 25 AH all the way up to 200 AH. I have tried with all of them, with exactly the same results as mentioned in my previous post.

4. I don't have any other 8S pack to test with, but we removed the faulty cells 7, 8 from the pack and check their voltage individually , which turned out similar to all the other cells. This is the first lithium pack that we are doing.

The PL8 worked fine when charging the cells individually, except that it was over reading voltage by 0.191 V per cell compared to a simple voltmeter.

5. Node wiring is set to fma , but I also tried the XH option and with the xh option all the six or seven cells show the same voltage, almost like it is averaging the entire pack voltage

6. I'm using a 600 W variable voltage power supply with a maximum of 18 V and 33 A. I can try with the battery pack and get back

7. Have attached your presets that I'm using… Filename JD.zip

[Burgerman]

>>>1. all the ring terminals for interconnect, power and balance cables are only crimped and no soldering. The only thing that is soldered is the D sub connections. I'm attaching a picture of the crimp

Thats what I thought.
Even without this problem thats a really bad idea. When you connect and crimp you are joining disimilar metals and that forms a chemical "cell" by pushing different metals together. That joint makes a voltage. That alone can give anything from 0 to .5 (500mV) of a volt across a single joint. That will vary depending on crimp quality, humidity level and age and oxidation level over time. And we are trying to balance to a 1mV accuracy... Solder everything! It also could just be a crappy bad crimp connection causing your main bigger problem we have here.

>>>2. we have not tried any 1A load on any of the balance wires as we are only trying to monitor all the cells. I will try it and get back to you.

OK
When you do that voltage may "vanish" due to a high resistance crimp.

>>>3. Your preset file had eight balance presets starting from 25 AH all the way up to 200 AH. I have tried with all of them, with exactly the same results as mentioned in my previous post.

They may all have something I missed. Post the one you are using.

>>>4. I don't have any other 8S pack to test with, but we removed the faulty cells 7, 8 from the pack and check their voltage individually , which turned out similar to all the other cells. This is the first lithium pack that we are doing.

The PL8 worked fine when charging the cells individually, except that it was over reading voltage by 0.191 V per cell compared to a simple voltmeter

Thats because you ad no accurate voltage monitor which is what a cell balance wire does. If no balance wire exists you are seeing the voltage at the charger under load as it charges. So incliding the cable(s) and connectors resistance loss. Which if these are crimped at any point will be even greater.

5. Node wiring is set to fma , but I also tried the XH option and with the xh option all the six or seven cells show the same voltage, almost like it is averaging the entire pack voltage.

With less than 8 cells it matters because the wiring at the charge balance connector changes. With 8S it shouldnt make any difference anyway. With FMA wiring you can charge via balance portes at 3A max without needing a full charge cable. Which I do all the time on hobby packs.

6. I'm using a 600 W variable voltage power supply with a maximum of 18 V and 33 A. I can try with the battery pack and get back
OK

[Burgerman]

Power supply.

Do you have a voltmeter or multimeter or occiloscope or anything that can measure the supply voltage and look at its PEAK high/low values?
Its output needs to be smooth like a battery. And stable. And not noisy.

If it works on a battery your supply is dodgy...
If it charges a tiny 8S hobby battery then the supply and the charger are fine.

Are you sure you have all the balance wires in correct order???

Do you only have 1 PL8?

Also no preset??

I suspect that somewhere in one of your connectors or one of your crimps theres a bad connection. Maybe where it connects to the PL8 or someplace. Ir it wouldnt detect correctly at all. Try deoxit, wiggle connectors.

[jehan]

This is the preset I'm using.
50 AH to 100 AH charging at 25 A

[shirley_hkg]

You started with the first cell's negative as ①, instead of (0). Then the last cell's positive should be ⑨.

However, I saw it is labelled ⑧. Something is missing.

Line them up neatly so you can spot the error more easily.

[jehan]

Hi Shirley… How are you

This is the wiring formula that I'm using.

160Ah for 2x group 24 v6.png (88.05 KiB) Viewed 295 times

The black balance wire on cell 1, is the equivalent of 0 wire in the above drawing..... And the red wire (or the last wire in the balance cable) balance wire number 8, goes into cell 8… Just like the drawing

John... I only have one PL8

[jehan]

These images might be better.

All the balance wires are blue in color.
The ground for the balance cable is black in color

[shirley_hkg]

You may have a faulty PL8. I had a same occasion. Wish you luck.

[Burgerman]

Preset looks fine.



I suspect that somewhere in one of your connectors or one of your crimps theres a bad connection. Maybe where it connects to the PL8 or someplace. Ir it wouldnt detect correctly at all. Try deoxit, wiggle connectors.

[jehan]

I really hope it isn't the PL8 that's faulty.

I'm very keen to install the lithium into the chair as soon as possible.

Everything is working fine on the PL8, we've even checked the continuity on the inside of the PL8 JST PA connector (Opened up the PL8) and all the balance wires were coming through.

It's just cell 7 that shows voltage intermittently and cell 8 which never shows voltage.

Once we try what BM has suggested, we will have a better understanding. I'm sure we will work it out

Even when we get this one working, I will need a backup for the PL8 anyway, what are the options now?

Thank you for checking the preset BM.

if the below is not clear , Is there any way I can send you a video to explain it?

I haven't tried charging the pack, but when I try to monitor the pack, it detects all eight cells but only shows voltages for seven cells and then immediately diminishes to 5 cells, three cells , one cell and then shows a BAD CELL COUNT and stops monitoring.

We did try some contact cleaner and a toothbrush on the pl8 balance connector on Friday. Could do it again.

UPDATE: downgraded the firmware from 3.36 to 3.22 and there was no difference. Today tried firmware 3.30 and now we are getting cell 7 showing up A lot more consistently, but not perfect.

Only cell 8 is still showing as 0.000

Please send me the latest version of CCS or should I just try reinstalling what I have ?

It's just cell 7 that That shows voltage most of the time and cell 8 that always shows 0.000 .

[Burgerman]

Use 3.35 or 3.36 as anything earlier has various issues.

It should show all cells on EVERY firmware version. The fact that its intermittently showing 7 says bad connection someplace.

Power supply noise or bad connection is my guess. Or defective charger. Solder!

Power PL8 from a lead battery or your car. What does it do?

I have 4 PL8s and never managed to kill one yet in god knows how many years. And a 5th one that was sold to me as faulty, with innacurate balance on 1 cell. But that also works fine anyway.

[shirley_hkg]

That so-called faulty one was free of charge, except shipping.

[jehan]

I have a friend in Hong Kong right now and will be leaving back to India on Tuesday evening or Wednesday morning.

Any chance you might have a

Power supply
pl8 charger
balance cables

Ready for me to pick up?

[shirley_hkg]

PM sent. Check your mailbox.

[LROBBINS]

I have two 208 AHr packs, one in what was Rachi's chair and still hasn't found a home, the other kept in the garage as a spare. Given that they are unused and unconnected, I charge them once every 6 months an discharge to ca. 70% for storage. The one on the garage floor does get kicked about some. The last time I went to re-charge that pack it gave nearly the same faults as Jehan has described. It turned out to be an intermittent balance lead, but not because of a bad (soldered) connection to the ring terminal. It was a fracture of the balance lead itself near the ring connector. So - do follow John's advice and solder your connector, but also jiggle those wires about a bit while the PL8 is trying to read the pack just in case the same thing has happened to you as happened here.

[Burgerman]

That so-called faulty one was free of charge, except shipping.

Yes free to good home! Sorry! Mostly used on 4S and 6S hobby stuff.

[Burgerman]

I have two 208 AHr packs, one in what was Rachi's chair and still hasn't found a home, the other kept in the garage as a spare. Given that they are unused and unconnected, I charge them once every 6 months an discharge to ca. 70% for storage. The one on the garage floor does get kicked about some. The last time I went to re-charge that pack it gave nearly the same faults as Jehan has described. It turned out to be an intermittent balance lead, but not because of a bad (soldered) connection to the ring terminal. It was a fracture of the balance lead itself near the ring connector. So - do follow John's advice and solder your connector, but also jiggle those wires about a bit while the PL8 is trying to read the pack just in case the same thing has happened to you as happened here.

THIS!!!

[jehan]

Thank you for all the possible options.

deoxit
Charge with car battery
solder all connextions
fractured wires

I will start trying them out tomorrow and get back.

[jehan]

Hi… I've got a new PL8 on the way from Shirley… It should reach sometime this week.

In the meantime I've been using the 100 AH pack for the last three days.

I have charged the cells individually to terminate at 100 MAH CV and installed in the chair.

After three days of use, the voltage is 26.6 V.

I am trying to charge the pack unbalanced.

I tried to use the existing preset and removed the balancing option.... But it still looks for 8 cells and gives a bad cell count.

I would like to charge the pack as a whole without balancing.

Please let me know how to do it?

Do the balance cables need to be plugged in?… I tried both with balance cables and without… And I still get a bad cell count

[Burgerman]

You cannot charge unbalanced. And should not charge that way. Which is why it insists on balance connections for the safety of you and specially the battery.

[shirley_hkg]

Hi…

I have charged the cells individually to terminate at 100 MAH CV and installed in the chair.

After three days of use, the voltage is 26.6 V.

I am trying to charge the pack unbalanced.

Still plenty to use @26.6, I'd use it till 25.8v

Charge unbalanced up to 27.00V

[jehan]

Thank you BM and Shirley....

I hope shirley PL8 comes this week, so that we can see where the real problem is.

I've had an issue with the dynamics DX control system (original On the lifestand lsc), if I turned it up beyond speed 2, the control system would trip and shut off, Sometimes on flat surfaces, but definitely on ramps… The only way to reset it was to remove the motor connections or the Anderson connections to the battery.... And it would start again.

So, I was just running it on speed 2 and it was very slow. I thought the problem was the 35 AH lead acid batteries... But I had the same problem after switching to 100 AH lithium.

I spent the last couple of days transplanting the VR2 controller, joystick, motors and actuators (From a karma standing wheelchair) into the lifestand chair.

After some changes using the mobility PC programmer (thank you BM and Woody).... It's running like a dream.

Since my existing PL8 balancer , is not reading a couple of cells Is it possible to set up the pl8 to emulate a dumb charger and plug it into a JK BMS to handle the balancing side of things?

[Burgerman]

Not really. If you have a power supply already and a BMS then the PL8 isnt needed.

There IS a BMS version profile but it has very restrictive charge options for safety reasons.