PINNED - Lithium battery conversion/info

[shirley_hkg]

This is my first self-assembly pack wih A123 pouch , back in 2011 .

This time I discharged it real low (3.05V) , to see how much are left after 6 years of use .





Below shows cell voltages of the last 1Ah .

Cell 3 has been with a swelling cell , so I added an extra 30AH to salvage it .

[shirley_hkg]

AND RECHARGED

There is the fuse betwen cells 3 & 4 .

[Burgerman]

200Ah? But a few bad connections somewhere? On the yellow one?

[expresso]

thats not bad for 6 years considering it was using a BMS -

[robert97]

yes, PS24V50A-BL-US $229.95 *might* be bad, but

after going through two PL8s, two FUIM3s,
and two laptops, i tried charging from a 12v lead battery.
the disconnection problem ended. so revoletrix sent a new
PS24V50A-BL-US . the disconnection problem returned.
i finally bought a 30v PS and all is good.

my reason for posting is to possibly save others from this grief.
so, if during charge your pack voltage rises from 23.5v to 24.8v
and your supply is about 24-26v and your PC CCS disconnects,
try a different voltage supply.

[expresso]

Which PSU did you buy - can you post a link - always good to know what works if ever needed

all of my PSU came from Ebay - and all work - they are all used server units - less than half the cost of new ones and so far i never had any issues - but in the event i get issues - i like to know what other PSU units everyone is using that work for them -

thanks

[Burgerman]

It pays to have an adjustable super stable bench supply. You choose any volts. And it doesent do this kind of thing even if you dont. But it shouldnt anyway.

[expresso]

It pays to have an adjustable super stable bench supply. You choose any volts. And it doesent do this kind of thing even if you dont. But it shouldnt anyway.

i guess if your having issues - - i only paid $100 for mines and so far so good - the second i got i paid $125 - works fine - i worry if i cant find them again if i need in the future - i dont think those sold by Revo - are worth it - they seem to have issues - others have same issues

[steves1977uk]

I don't have any issues using a 24v PSU with the PL8, I do have a bench 0-30v adjustable PSU too like BM has should any problems occur. Like BM says, it shouldn't matter how many cells in series are being charged, the CCS software shouldn't lose the connection to the PL8 unless there's an issue somewhere.

Steve

[ex-Gooserider]

For what it's worth, I thought the USB cable I had been using was the one that came with the Revolectrix FUM board, but I'm not certain - I have so many different USB cables in my space it's hard to keep track sometimes...

At any rate, the one I had was only 3-4' long, but the cable OD was pretty thin (hard to tell what is under the jacket w/o surgery....) It should only be carrying low currents, but even so this cable seemed thin, so a bad cable was possible... It also seemed like an easy thing to check, so I dug through my box of USB cables and found one with the right ends and which was a larger OD on the jacket, and also had 'shielding beads' on each end next to the connector....

I haven't tried it on the XP box, but on the Win-7 box, it seems to have solved the problem, in that the timer on the software never stops. It still takes a few seconds for the graph to start displaying data, but when it does, it seems to do so from the beginning...

I've been charging cells, and it seems like I'm getting a good bit of variation in the time to charge, and mAh returned... I had one cell that never did stop by reaching 20mA, instead it hit the safety time out at 4 hours.

I had another one that did an over-voltage safety stop - the graph seemed to be doing fine until the last few seconds when it went from 3.6 to over 4V
in just a few seconds... Otherwise it was about average for mAh returned, charge time, and cell resistance.... Strange...

ex-Gooserider

[Burgerman]

I had another one that did an over-voltage safety stop - the graph seemed to be doing fine until the last few seconds when it went from 3.6 to over 4V

I suspected a cable. USB cables are crap!

That fault above is always a bad connection. As for a cell that doesent fall to a low current, it can happen and the same cell will behave normally next time. Not sure why.

[expresso]

If your charging the cells a few at a time - maybe you can first get a working Cable - working system computer and charger PSU - then i would charge each cell one at a time - good connection - yes it takes longer - but it may be more accurate - in the end when you build it - if the mAh returned are not correct for some other reason - connection etc, - then the built would end up not as tight -

i recall you built some unit to charge a few cells at a time to save time ?

[ex-Gooserider]

The over-volt cell was with the good? USB cable - at least it hasn't given any other problems...

I built a jig months back when doing the initial charge, which allowed me to do 4 cells at a time. Essentially it was two blocks with holes for the cell ends, with tinned copper braid for contacts, and a spring to force the connection on each cell.

I am using the jig again this time, but only doing one cell at a time, and using the same position to do every cell.

Latest frustration was with the copy of MS Excel that was installed on the Win 7 box when I got it... I do NOT like programs that CHANGE the data you enter, after you enter it...

Just solved it, downloaded a copy of Libre Office, sneaker netted it to the Win 7 box, and installed it - no problems, no difficulties just like most Free software, and unlike any of the Wincrap that I've dealt with... Opened the spreadsheet file, which had my data still in it (reversing the Excell diddling) and saved it as an ISO standards compliant .odf file...

Programs that Just Work are so nice...

ex-Gooserider

[Burgerman]

Strangely enough, every single version and release of office since office 97 onwards just worked fine too. Only you seem to have a need to use something different to the most popular operating system and office suite on the planet, universally used in the workplace and industry.

Not saying that whatever you used instead doesnt work too, but why do you always want to be on some betamax operating system/office etc?

[Burgerman]

Exspresso, and other lithium/rnet users.

These are the settings you might get best warning from.
Also once I have a word with PG drives I think we can adjust the calibration to read "just" full, after the first few yards. And then the auge wont be accurate, but will start to drop after some use so you know where you are. If they wont tell me then I will break out my meter when I convert the new rnet chair to lithium in a month or so. Since I think I can get it working. At least to a degree.

You can set 6 or 8 bars if you wish. So it warns you before any damage.

[expresso]

i believe this is what i have current - been a while since i went in there - next time i will double check - should i set the flashing bars to 6 then ?

battery level etc, ?

[expresso]

BM - when you get your Rnet going and if you can figure out which setting i need to change to make my chair not slow down if i raise the seat lift up - i dont plan to ride this way but just in case its needed or for some reason gets stuck in slow etc, if it dosnt lower all the way - good to know what to disable in that event

it should be in this section here - but me knowing for sure - i wont play around with guessing unless i have no choice - i know i can always reprogram if i make a mistake - i rather make a change when in know which one to change -

maybe your chair may be limited in the same way ? or maybe its different in the UK -

[Burgerman]

Set them to flash, and alarm at the point where they normally start to drop, or the point where they are after a long run. About 80% of the trip. Se wiring mOhm lower to reflect the better cables you have. Say 10 or 20. Power will cut off at 22v which is 2.75v. But thats low! So set the 255 secs to 60. Or 30 secs. So you dont run them even lower up some hill.

[Burgerman]

Send me your saved file. Just add .zip to the file name and add to next post. As I dont know which actuators are connested to what/which module! Might not help me. But if I was there I would just change one thing at a time till I find the right device/channel then experiment.

[expresso]

after a 44 mile ride - i have all my greens on my JS - so not sure where to set it etc, - i figured i set it to flash at 3 bars warning me its getting low and cut off at 22V - should i change that to 22.5v or 23V ? -

even if my wires are thicker - i used 8AWG - i dont know if my Chair wiring for power is the same or thinner - i am sure they are not thicker - but if they are thinner - shouldnt i leave that alone ?

the thing is this - the seating part of my chair - is not stock from Sunrise - its from another company - Motion Concepts - adds the upper part to the sunrise frame
and the program settings i am sure are from Motion and not Sunrise i would think -

i think this is the current settings i am using - i have so many saved that i am confused what i am using - when i connect it again to check - i will save the current on the chair and the original i have and delete the rest - getting to confusing now - i have dozens of settings saved-

i only need the original - and what ever i am using now -

take a look at this -

[Burgerman]

Nope. Too many possibilities. You will need to experiment.

[shirley_hkg]

Exspresso, and other lithium/rnet users.

These are the settings you might get best warning from.
Also once I have a word with PG drives I think we can adjust the calibration to read "just" full, after the first few yards. And then the auge wont be accurate, but will start to drop after some use so you know where you are. If they wont tell me then I will break out my meter when I convert the new rnet chair to lithium in a month or so. Since I think I can get it working. At least to a degree.

You can set 6 or 8 bars if you wish. So it warns you before any damage.

Beware ! This is only viable with an assumption that all GROUP of cells are of the same capacity , that their voltage difference are only minimal through out the entire discharge .

However, only John's pack could perform this way , as all his cells went through the tideous capacity screening and thorough matching process .

I haven't seem anyone else has done the same yet .

[shirley_hkg]

THE weakest group will always hit the bottom , long before the battery volt gets lower than 25V .

All lazy users like me assemble our packs at will , WITH DISCHARGE RESULT AS BELOW NATUALLY ..

[shirley_hkg]

A voltmetre + cell alarm are safe .

Eventually will go to cell phone via bluetooth

Original battery gauge is never meant for lithium after all ..

[shirley_hkg]

[expresso]

I may just make a cell monitor this winter - just to see - - but in my case - i have two packs - the full 105ah in the chair and the ADD ON 30ah in the rear - now if i make a cell monitor - i would connect it to the full pack in the Chair ? i know it would only show the Cells from that pack only - but that would be the most important to me - the ADD ON is my insurance to keep my Full pack in shape -

so far its going on my Third summer coming up and i just been using my JS Milage - with a 135ah pack - i am good for easy 45 Miles and cells are safe - never below 3.1v after 45 Miles - thats the most i have done so far in one Trip - now i understand it can change depending how you ride etc, - 45 Miles one trip can be different from another 45 Mile trip -

but theres still enough room and the lowest cell group never went below 3.1v during my usage so far - i feel fairly safe this way for now - now if i started to do 50 miles and more - then i would have to be concerned - i had my chair sitting for about 2 months - i used it here and there short trips to store etc, - about 10 miles over a 2 month period - in the house just moved if in the way -

i recharged and balanced just fine - i used 27 ah from the 105ah and 12ah from the 30ah pack - so far so good - well see this summer coming - my way is not the best way for sure - but its working for me at the moment - i have to make a cell monitor just to see now -

[expresso]

Nope. Too many possibilities. You will need to experiment.

i wont mess with it - since its not giving me any issues - i have no need to touch those settings - but i will adjust the battery section - and lower the low voltage time etc, - raise the cut off point to 23v or 23.5v - that should bring it to about 2.8v or 2.9v a cell - 24v should be fine also at 3v per cell ?

i never noticed it getting lower than 25.6v or 26v after a full days use - when plugged in to recharge - thats how i check it - - 23.5v or 24v ? which is better to make sure it dosnt cut off when riding

[Burgerman]

Its actually easy to set inhibits, battery calibration etc. But you need the chair connected, and in drive mode. Then go to diagnostics on the top bar, and play! Real time voltages etc. And real time inhibit and module figures. Allows you to figure out which seating actuator uses what settings.

[expresso]

Its actually easy to set inhibits, battery calibration etc. But you need the chair connected, and in drive mode. Then go to diagnostics on the top bar, and play! Real time voltages etc. And real time inhibit and module figures. Allows you to figure out which seating actuator uses what settings.

Ok - i am not worried about it that much at the moment - i leave it alone for now - but the battery low voltage cut off - - i have it set to 22v - -would it be ok to raise that to 23.5v or 24v ? and lower to 60s instead of original of 255s - ? Up till now - they never showed below 3.1v when i get home and connect to recharge -
and i believe 25.6v was the lowest it reached on the pack - or 26v - i cant recall which it was for sure - -

[Burgerman]

You cant. 22v is the highest. They are expecting lead. Yes 60s.

I want to know what "calibration" actually changes I nned a chair and a voltmeter to find out.