PINNED - Lithium battery conversion/info

[expresso]

before

[terry2]

after making wire cables for my 80ah pack - the charge graphs are perfect - cant get any better - they were not bad before -

one pic is before - the perfect line is today after - i now know what to do if it happens again - since i added lock washers to the only 4 that were a bit stripped with larger screw - if i have to redo it again - i will add all lock washers with a touch of locktite and all get larger 10mm screws - change the one wire cable thats not bent - and that should be it -

very happy with these 80ah Cells so far

That looks spot on.
My cables are not right. But trying to find what I am doing wrong is a head banger.
I have made new cables 4 times now

You've got nice hands Terry . Mine are filthy and cut to pieces



Thank you Woody, but I saw your post too late . What you linked to looks perfect!!! .

I ordered this https://www.ebay.co.uk/itm/1-mm-A4-Lexa ... 2749.l2649 this morning. I'll give it a go, but if it doesn't work I won't have lost much and will order that screen.

My sister makes me use those surgical rubber gloves.

How flexible? Like a cable?

Yes. The middle part that is covered up can twist\bend\up\down. I may try them when I have nothing to do.

[Scooterman]

after making wire cables for my 80ah pack - the charge graphs are perfect - cant get any better - they were not bad before -

one pic is before - the perfect line is today after - i now know what to do if it happens again - since i added lock washers to the only 4 that were a bit stripped with larger screw - if i have to redo it again - i will add all lock washers with a touch of locktite and all get larger 10mm screws - change the one wire cable thats not bent - and that should be it -

very happy with these 80ah Cells so far

Smashing graph expresso

[terry2]

Place your bets!

I know BM will have a field day with me for doing this. BUT

I have stripped and rebuilt my pack using the bars\connectors I was sent from china(he does not want them back)

I am now going to charge the pack. Will be better or worse?
I will post a graph after.

Place your bets

[Scooterman]

Fingers crossed for you Terry

I really hope you get a good graph, I'm hopefully confident for you. Hard work deserves reward.

If you remember can you also post the resistance graph as well

[LROBBINS]

Terri,
at least they are tinned so you shouldn't have any problem with copper oxidation

[shirley_hkg]

I'd open up shrink tube to see one inside.

[terry2]

I'd open up shrink tube to see one inside.

I did and it's the copper plated strips a tiny bit lose so they can bend.

Terri,
at least they are tinned so you shouldn't have any problem with copper oxidation

Thanks dude.

Fingers crossed for you Terry

I really hope you get a good graph, I'm hopefully confident for you. Hard work deserves reward.

If you remember can you also post the resistance graph as well

Graphs posted.

About the same results. So I will take it that those 2 cells are different from the rest.

[terry2]

My graph from before

download/file.php?id=10805&mode=view

[Scooterman]

Internal Resistance is really low Terry, that's great

I don't know why them two cells shot high first, BM will know (and Shirley will know too).

I wonder whether it's because:

a) they are weaker cells and have higher resistance so voltage shot high first, although IR looks great .

b) they are stronger cells and discharged less so became full soonest.

BM will be able to answer, I'm interested

[terry2]

Internal Resistance is really low Terry, that's great

I don't know why them two cells shot high first, BM will know (and Shirley will know too).

I wonder whether it's because:

a) they are weaker cells and have higher resistance so voltage shot high first, although IR looks great .

b) they are stronger cells and discharged less so became full soonest.

BM will be able to answer, I'm interested

Glad you said the "Internal Resistance " is ok. As I haven't got a clue what it is

I think I may discharge the pack to 2.90 on one cell.
BM says as long as it doesn't get and worse. I will be ok.

[Scooterman]

Glad you said the "Internal Resistance " is ok. As I haven't got a clue what it is

Your IR is the lowest I've seen, it's fan dabby dozy

The lower IR the better

Re discharge to 2.9v. It will take a couple of days terry, and if you don't like fan noise do it in a room you don't sit in.

[shirley_hkg]

Experience tells the weaker cells rise sooner . The IR seems too good to be true to me also . PL8 is not good at this.

Switch to MONITOR as soon as recharge ended , to log the voltage drop and graph it for an hour or two .

Discharge the entire pack as one to 2.95V to find out . You will be well rewarded.

[terry2]

Glad you said the "Internal Resistance " is ok. As I haven't got a clue what it is

Your IR is the lowest I've seen, it's fan dabby dozy

The lower IR the better

Re discharge to 2.9v. It will take a couple of days terry, and if you don't like fan noise do it in a room you don't sit in.

Well at least I have one thing right

Experience tells the weaker cells rise sooner . The IR seems too good to be true to me also . PL8 is not good at this.

Switch to MONITOR as soon as recharge ended , to log the voltage drop and graph it for an hour or two .

Discharge the entire pack as one to 2.95V to find out . You will be well rewarded.

I will do that now.
Thank you all for your help.

[Burgerman]

Imagine 'someone', say 'a manufacturer' just for a laugh, came up with a modular design that lets you add the motors & wheels, casters, seat and armrests to the battery box that suits your needs best, with that battery box being the structural base frame.
You'd transplant the parts to a new battery box with more cells as you grow (kids could even start with less ah I assume) or as your budget or mobility needs change...
It's basically the BM design without the tubular frame but with the casters and seat to be attached to the battery box as well.

You can choose a layout based on your budget, your size, your activity... anything really.

Modular...

Runs away screaming! The exact opposite of whats required

[expresso]

thanks Scooterman - Terry - time will tell if my pack lasts and dosnt change - if it does - i know what it is and will fix it better -

Terry worse case your Cells are just a bit different - but as long as you can use your Chair all day and not worry - and recharges fine etc,

its a hit and miss with these Cells - now unless you want to really rip the pack apart and test each cell - then rebuild - better connections etc,
thats alot of work - may not be needed at all - follow what BM and Shirley suggest - they usually correct

[terry2]

thanks Scooterman - Terry - time will tell if my pack lasts and dosnt change - if it does - i know what it is and will fix it better -

Terry worse case your Cells are just a bit different - but as long as you can use your Chair all day and not worry - and recharges fine etc,

its a hit and miss with these Cells - now unless you want to really rip the pack apart and test each cell - then rebuild - better connections etc,
thats alot of work - may not be needed at all - follow what BM and Shirley suggest - they usually correct

Yes you are right.

Here is the graph from monitoring. Any thing stick out?

[Scooterman]

Here is the graph from monitoring. Any thing stick out?

Nope, not as far as I can see

Are you going to do a deeeeeeeeeeeep discharge?

[terry2]

Here is the graph from monitoring. Any thing stick out?

Nope, not as far as I can see

Are you going to do a deeeeeeeeeeeep discharge?

Yes I am.
I won't leave it on over night though.

[shirley_hkg]

It is safe to run overnight , at least in discharge wise .

[terry2]

It is safe to run overnight , at least in discharge wise .

I have left it discharging

11 hours so far. The cells are at 3.308V and 39000mAH have been taken out.
Good job I am not going out this week

[terry2]

Just an update

It's been discharging for 19Hrs and 55 mins. OUT=72513 Cells are 3.272

A long way to go yet

[Scooterman]

Just an update

It's been discharging for 19Hrs and 55 mins. OUT=72513 Cells are 3.272

A long way to go yet

Sometime tomorrow late afternoon I would guess?

Is the fan noise getting on your nerves yet?

[terry2]

Just an update

It's been discharging for 19Hrs and 55 mins. OUT=72513 Cells are 3.272

A long way to go yet

Sometime tomorrow late afternoon I would guess?

Is the fan noise getting on your nerves yet?

I just turned off my hearing aids

I have lifted the four corners of the PL8 to let the air blow out and about.

[Scooterman]

I have lifted the four corners of the PL8 to let the air blow out and about.

Yes you can’t have too much ventilation terry, as the vicar said to the actress (not sure that works )

[terry2]

I am a bit worried about the discharge.(see picture below)
It's still at 3.22V with 131990 mAH taken out. Should I stop it?

[Scooterman]

No, nothing wrong with that Terry, keep going

[terry2]

No, nothing wrong with that Terry, keep going

Thanks dude.
140 AH out now, and still at 3.207V. I will be glad when it's done

[Burgerman]

You will know when its done. If you are using a preset I sent you, it should stop when the lowest cell drops to 2.90V and they will start to fall suddenly. THEN read the capacity, and you will know how much Ah you REALLY have. And which cell is the smallest capacity. The one that drops first.

Just go to the presets, discharge tab, check that it is set to 2.900V per cell. You cant change it without stopping discharge though... So dont.

[terry2]

You will know when its done. If you are using a preset I sent you, it should stop when the lowest cell drops to 2.90V and they will start to fall suddenly. THEN read the capacity, and you will know how much Ah you REALLY have. And which cell is the smallest capacity. The one that drops first.

Just go to the presets, discharge tab, check that it is set to 2.900V per cell. You cant change it without stopping discharge though... So dont.

Thanks BM
I always use your profile.

It does say Discharge Voltage 2.90V
So I will leave it and take pics when it stops.

1 day 17 hours Cap out 152977 mAH and the cells read 3.179V. I hope it reaches 160AH