PL 8 - Q and A section - How to Set up - Use etc,

[expresso]

Download again, Above was re-uploaded,

I made some hidden changes to give less errors and fixed the charge voltage which I set to 3.555 instead of 3.550.

Ok thanks - for some reason - i cant never open them when i use my desktop - from here - on my laptop works i believe - will try later

[expresso]

This is if and when i get my new chair - i am not going to touch it - or remove BMS etc, - at least not for some time - Warranty issues etc, - insurance paying for a high price tag - they wont be happy if i touch something like that and then something goes wrong for what ever reason - even if it has nothing to do with what i touched - i will be blamed -

i figure just to have a preset for the PL 8 in case i needed it - or like to try using that instead - who knows - just having another option - there charger is 10A - if i get a manual with it - with details - then i can know for sure what the CC before it goes to CV - i would say 29.2V or even 29.6V - which is high - they lean on the BMS to do the work and we know it wont do a good job - but if it fails because i touched it - then i am screwed - even with this BMS and the way i would use it - it could easily last 5 years - unless the Cells are really crap to begin with -

[expresso]

Got it to open - its fine -

[Burgerman]

They need renaming. From
xxxxx.PL8.ZIP to
xxxxx.PL8

Of course if your computer is all set up in full retard mode you will never see the last few letters after the dot!

[expresso]

They need renaming. From
xxxxx.PL8.ZIP to
xxxxx.PL8

Of course if your computer is all set up in full retard mode you will never see the last few letters after the dot!

no that wasnt the case - i had to assign a program which opens it and i did - pointing to the charger software and its fine - renaming it was fine - just no program to open it was set up on my desktop since i never use it for charging -

just a backup in case laptop is out of order - either way dosnt matter - can use with out computer if needed

[Burgerman]

You don't need a program set to open it. Open the charger software.

Decide a position, like 1 or 4 or whatever, where you want it. And select it.
Then from the menu choose file > "open file to preset 4"... Find it, choose it,
And it loads it into the charger control software in position 4...

You save them the same way.

[expresso]

yes i understand that - if a set program is assigned to this kind of File - i can just click the file - preset and it would open the software on its own -

or open the software and do as you stated - same thing - its best to have a program assigned to it so it knows what to do when clicked - it wont show up as a blank box - and if you click the blank white box - it does nothing - with set program - its noticeable what it is - and works by just clicking the file

will work either way - now anytime i download a file of this kind - it would be ready and show up correct on the desktop etc

[shirley_hkg]

It will stop only if nothing reconnects for quite a while. Any bms that disconnects for that long needs to be filed under BIN regardless!

It depends . Larger the pack, longer it stops .

80mA to balance a 40Ah pack will trickle in 15 mins interval .

100 Ah pack will have to wait for an hour to reconnect again .

Is it quite a while , or it isn't ?

[Burgerman]

Never tested on a huge pack. Works on a out of balance 70Ah lead brick replacement. Eventually. But its got an 8 hour charge limit. So had to be restarted. That cooks the high cells for 24 hours! Why dont they make these things with 2, 3 or 5A Balance? What use is 50 to 100mA?

And it depends on how accurate or fast the BMS is. Some are proportional. Most digital which isnt as good. Some very tight voltage limits, some allow the volts to climb too high then shut off for ages until its too low, and then start again. (greater hysterisis) which damages cells more... Some flicker on/off fast so charger is OK.

Try it. You may be surprised. Works fine on smaller packs. Should be OK on larger ones too. But of course the real problem is that the BMS is in the wrong place, and cant control the charger propotionally and has no control than ON/OFF repeatedly if a cell goes over a (too high) voltage...

Best bet, throw the BMS away, or just add a balance connector and charge cable as well and ignore it. But even then some of them do very undesirable things.

The last one I looked at was trying to balance at ALL voltages. So it takes the warmest cell (marginally higher voltage) and discharges it all day long! On a large pack that can be a large temp difference. So the battery ends up miles out of balance. More volts does not always mean that its at a higher state of charge. Another on my mower pulls power from 1 cell to power the BMS 24/7. Its a small current but a week into storage and its a full Ah out of balance! So with 100mA balance ability it takes TEN HOURS at CV to correct itself. Which cooks all the other high cells. And it doesent eveN do its rated 100mA! Nearer 60...

BMS are allmost all crap! And do unknown undesirable things. The better logic controlled ones are worse. The programmer usually doesent understand batteries and loves electronics or proframming. And what you get is anyones guess.

[shirley_hkg]

Try it. You may be surprised. Works fine on smaller packs. Should be OK on larger ones too. But of course the real problem is that the BMS is in the wrong place, and cant control the charger propotionally and has no control than ON/OFF repeatedly if a cell goes over a (too high) voltage....

YES . Small pack is OK , and we still use it with ADD-ON packs .

Our packs are large ; 135 --- 250 Ah , so we move on with PL8 ; despite its inconvenience .

[snaker]

Does PL8 software allow to delete all its original presets? I want to keep just a custom preset to prevent mistakes.

[expresso]

Does PL8 software allow to delete all its original presets? I want to keep just a custom preset to prevent mistakes.

i think you can maybe - you can hide them for sure - lock them so they cant be messed with - theres also a Clear option - which i think would delete it-

i havnt tried that - i just checked and it will clear that preset once you update it - i didnt try to update it - i believe it will if you choose clear and update -

[Burgerman]

You can hide all but theone you need. But you wont make a mistake. Its quite easy and it remembers. Or you can keep just a few that you use. If you connect the wrong battery type or something it cries and stops. So its quite hard to screw up unless you try hard. Although I almost charged my camera battery at 40A once! It wouldnt have liked that.

[expresso]

does the Clear option delete the preset all together ?

[snaker]

It's my dad who will use the PL8 and he cannot read English. He always has to struggle to remember just a English word and then forgets it in the next day. It's good for me that PL8 already automatically prevents his mistakes.

BM, I find a cell that is only 2.3V. I will charge it first. Can I still use your preset to charge it? Do I need to change any parameter?

[Burgerman]

2.3? Be very suspicious.

It may not want to charge it if below 2.7V and faulty. Try it. Set Amps to just 3A for a bit till voltage comes up to 3.00. The PL8 will try to charge at 500mA till it sees 2.7V. If that doesent happen it will give an error. You may need to restart it.

When I get cells from china, headways, A123, Hobby cells, etc they are almost always 3.35 to 3.5 and a bit volts. A fully discharged cell is really around 2.7V.

Taking them below 2.5V is a very bad idea! And below fully discharged level. Connect the low cell, to a higher cell or a few, first for 4 or 5 hours.

[snaker]

So I will change the "Charge Amps" parameter from 15A to 3A for charging this fault cell. While charging, I will monitor the voltage graph. If it reaches 3.0V, I can stop charging and then repeat to charge it with 15A "Charge Amps". If any error happens, I just need to restart PL8. Are those steps correct?

The problem of low voltages might be partly caused by myself. The bottom sides of all cells are not completely wrapped. I did not know the metal case is also the positive pole and I left these bottoms touched the ground in a long time.

[Burgerman]

To charge 1 cell it should not be set to 15A. 4 to 6 is a sensible rate. But a couple of amps is fine while its low. Just to bring it up a little which will happen very fast.

[snaker]

I am a little confusing. Is it that I should charge this fault cell at max 4-6A and I can charge the rest of cells (that are actually >= 2.8V) at 10-15A? I note each cell is nominal (not real) 75Ah and each time I only charge 1 single cell.

[shirley_hkg]

Line up all cells , and join them in parallel with 2 bare wires .

Charge it as ONE , at any rate you want .

[Burgerman]

Just charge with the preset for one cell, ignore everything else ere. Press go.

Or join 2 or 3 cells at once. In PARALLEL.

2X 75Ah cells in parallel is 150Ah.
3X 75Ah cells in parallel is 225Ah.

In both cases it just makes one big cell...

[snaker]

PL8 and cables just arrived. I will start charging each cell in tomorrow.

I read somewhere in this thread, BM said we should charge new cells at 3.550V instead of 3.600V in the first time. In the preset I see the charge voltage is actually 3.600V. Should I reduce it down to 3.550V?

[snaker]

Each time I run PL8 software, I see a message box as below. Is there anything wrong? Can I turn this message off?

pl8-mb.png (5.65 KiB) Viewed 11178 times

[snaker]

I am trying to charge the fault cell. PL8 shows an error "SAFETY CODE 34: Wrong cell count" as the image below. It seems that's due to the cell's voltage is too low. Can I do anything to fix this error?

[expresso]

PL8 and cables just arrived. I will start charging each cell in tomorrow.

I read somewhere in this thread, BM said we should charge new cells at 3.550V instead of 3.600V in the first time. In the preset I see the charge voltage is actually 3.600V. Should I reduce it down to 3.550V?

charge-voltage.png

I am pretty sure you can leave this alone at 3.6V - not to worry

[expresso]

Each time I run PL8 software, I see a message box as below. Is there anything wrong? Can I turn this message off?

pl8-mb.png

this i used to get also on my last PL8 i purchased - i didnt do anything to it and it finally stopped on its own - i believe its tested before being shipped and this is the left over from the testing - i was told by them when i called to ask -

after half dozen times i used it - i stopped and no longer happened - PL 8 is still working fine so far - check the errors - see if you can clear it there if there are any -

[expresso]

I am trying to charge the fault cell. PL8 shows an error "SAFETY CODE 34: Wrong cell count" as the image below. It seems that's due to the cell's voltage is too low. Can I do anything to fix this error?

safety-code-34.png

if your trying to charge just ONE Cell - you can lower the charge Rate - its showing 10A - that may be too much for a single cell - it may not be the error your getting - did you get a preset from BM for charging just ONE Cell at a time ?

thats the preset you need to use if charging just ONE CELL - double check

[steves1977uk]

I believe snaker is using 75Ah cells expresso, although 10A should be ok for these I would charge at 5A to be on the cautious side. Trouble with buying generic cells is we don't know their quality.

Steve

[expresso]

AHH yes thats right - i keep thinking always Headway cells -

[Gnomatic]

I believe snaker is using 75Ah cells expresso, although 10A should be ok for these I would charge at 5A to be on the cautious side. Trouble with buying generic cells is we don't know their quality.

Steve

I would think 10A charge would be fine for these 75Ah cells. Their max charge spec is 1C, which would be 75A. Unless I'm mistaken, a !0A charge rate on these cells would then be .13C. (if my understanding of calculating C rating is correct)

2.2v on the cell seems pretty low.