PINNED - Lithium battery conversion/info

[fishinjunky]

I checked the voltage at the terminals while charging with the multimeter it shows 3.3v . The charger display shows 3.8v output and the balance lead shows 3.3v on the charger display. I have it set to end at 3.6v

[fishinjunky]

You guys think the charger is displaying the 3.8v because of compensation for voltage drop in the charging leads. 0.2v higher than 3.6v at 20 to 30 amps ?

[LROBBINS]

0.2 V is the drop across 0.01 ohms at 20 Amps (E=IR,or rearranged R = E/I, so R = 0.2/20 = 0.01). Perfectly reasonable with connectors, wires and whatever the effective resistance of the input circuitry.

[Burgerman]

Yes.

[fishinjunky]

Thanks guys that makes me feel a lot better
Whan I saw the 3.8v I panicked and thought oh no I'm going to damage this cell

[fishinjunky]

The iCharger display shows cell IR 0.3 miliohm and the iCharger display shows 19.6 miliohm line resistance.
Are those numbers acceptable?

[LROBBINS]

19.6 milliohm = 0.0196 ohm, within measurement error of the 0.01 ohm estimated from voltage and current - so, yes, that's OK. IR of 0.3 mohm is also perfectly acceptable.

[fishinjunky]

19.6 milliohm = 0.0196 ohm, within measurement error of the 0.01 ohm estimated from voltage and current - so, yes, that's OK. IR of 0.3 mohm is also perfectly acceptable.

Thank you

[fishinjunky]

I didn't realize just how important it is to keep all balance wires and charging leads as short as possible makes a huge difference. It's convenient but takes a 40 amp charge down to 20 amp with long leads an connectors. What's the max length you guys are using 6ft?
I'm thinking I could get by with 5ft

[Burgerman]

No it doesent. It only slows charge when the cell voltage is seen as 3.6v towards charge completion. It simply causes cv voltage stage to begin tapering current off towards the termination current sooner. And so extends charge time by a few mins.

[steves1977uk]

Lenny, I think fishinjunky's using a generic 24v 69A PSU made from two PC Server power supplies. A ZXD2400 PSU would be better though!

Steve

[steves1977uk]

I didn't realize just how important it is to keep all balance wires and charging leads as short as possible makes a huge difference. It's convenient but takes a 40 amp charge down to 20 amp with long leads an connectors. What's the max length you guys are using 6ft?
I'm thinking I could get by with 5ft

I've used 2 metre cables (balance and power) and still charge at 40A using 10AWG for the main charge cables.

Steve

[shirley_hkg]

A ZXD2400 PSU would be better though!

Steve

No. It's not the PSU.

He is charging right, but it will be much quicker to charge at 8S. Balance later.

[fishinjunky]

I've got it dialed in now. Charging at 40amps. 44amps is most I can do with my 24v 69amp psu which is fast enough for me but eventually I'm going to want to max the charger out possibly with two Shirley psu in parallel. But that way down the road.
Everything is coming together getting all the soldering done teaching mom how she's doing really good.
I've spent alot of money on stuff I didn't need but I like what bm said it's not wasted money because I've gained knowledge an knowledge is priceless.

[fishinjunky]

I didn't realize just how important it is to keep all balance wires and charging leads as short as possible makes a huge difference. It's convenient but takes a 40 amp charge down to 20 amp with long leads an connectors. What's the max length you guys are using 6ft?
I'm thinking I could get by with 5ft

I've used 2 metre cables (balance and power) and still charge at 40A using 10AWG for the main charge cables.

Steve

Steve,
Who does your soldering? You or do you talk someone through it?
I'm talking my mom through it she's doing great. But it can get frustrating being unable to do it myself an waiting for others to get anything done. Of course I never show my frustration as I appreciate her help greatly.

[steves1977uk]

I used to have an ex-RAF chap make up my charging cables and build my pack. It is annoying having to wait for others to help people like us to do the work. One of my PA's daughters is into engineering, so I'm hoping I'll be able to learn her how to solder. She managed to rebuild a motorbike from scratch.

Steve

[Burgerman]

Being paraplegic I can do many things that need only hands. Inc soldering. Balance, getting stuff into position, dropping stuff that I cant pick up are my problems. Spasm kicks in while trying to reach things. Or to get into an odd position to see where I am putting a screw.

For e.g. I just built most of a complex heavy PC on my bed while in it. Its around 40lb now with a heavy case, heavy water blocks, glass sides etc. Everything done except the pipes and fittings. Thats hot air guns, junior hacksaws, files, templates, and manoevering that heavy case to get everything into the right position. I cant do this on my bed easily because of the sheer weight and balancing everything on me. instability. So a carer holds parts or the PC case in position etc. I do around 15 to 20 mins a day. Because thats not what they are paid to do... But we are getting there slowly. Today most of the stuff, scews, tools, etc was on the floor at least a dozen times. Its highly frustrating. I have the skills but positioning, balance (mine) and a lack of stability while balancing everything on top of me is the problem. But you learn to live with seemingly trivial things taking gargantuan effort and weeks in place of a couple of hours.


If you cannot use your hands at least normally it must be even worse. I feel for you!

[fishinjunky]

I used to have an ex-RAF chap make up my charging cables and build my pack. It is annoying having to wait for others to help people like us to do the work. One of my PA's daughters is into engineering, so I'm hoping I'll be able to learn her how to solder. She managed to rebuild a motorbike from scratch.

Steve

Hope it works out for you

I even tried using my mouthstick to solder while someone held the iron but can only splice wires I'm not consistent enough for the battery build though

[fishinjunky]

Being paraplegic I can do many things that need only hands. Inc soldering. Balance, getting stuff into position, dropping stuff that I cant pick up are my problems. Spasm kicks in while trying to reach things. Or to get into an odd position to see where I am putting a screw.

For e.g. I just built most of a complex heavy PC on my bed while in it. Its around 40lb now with a heavy case, heavy water blocks, glass sides etc. Everything done except the pipes and fittings. Thats hot air guns, junior hacksaws, files, templates, and manoevering that heavy case to get everything into the right position. I cant do this on my bed easily because of the sheer weight and balancing everything on me. instability. So a carer holds parts or the PC case in position etc. I do around 15 to 20 mins a day. Because thats not what they are paid to do... But we are getting there slowly. Today most of the stuff, scews, tools, etc was on the floor at least a dozen times. Its highly frustrating. I have the skills but positioning, balance (mine) and a lack of stability while balancing everything on top of me is the problem. But you learn to live with seemingly trivial things taking gargantuan effort and weeks in place of a couple of hours.


If you cannot use your hands at least normally it must be even worse. I feel for you!

Oh yes spasms they are always fun sometimes I feel like a fish flopping out of water when they kick off

What kind of mattress are you using. I've got one of those air mattresses for wounds its OK but it's loud. I'm still working on healing 3.

I'd like to see some pics of your PC build if you get a chance sometime it sounds awesome

[Burgerman]

It is. And I will.
And totally overkill. 16 cores, 32 threads amds fastest CPU and it will be overclocked as all my pc are. 128GB low latency ram, 3x 2GB NMe 980 pro drives, watercooled everything and custom loop with two rads and Ffront one is 420 x 140mm and 50mm thick alone.

Basically I am building this in this case. But with better motherboard, faster greater core count CPU, more memory, more storage, and better waterblocks and full EK system with a monoblock on motherboard etc and bigger radiators. And a 3080Ti graphics card. With 2 waterblocks obviously! But not yellow...

https://www.overclockers.co.uk/infin8-p ... 6f-oe.html

Is it cheap? No. If its worth ugrading you should go big or go home!

Theres a few components and waterblocks here. https://www.wheelchairdriver.com/board/ ... =5&t=11062

[fishinjunky]

Is it cheap? No. If its worth ugrading you should go big or go home!
f=5&t=11062[/quote]

I agree I love overkill.

[fishinjunky]

Is 16 awg to big for balance wires?
I'll be using three mt30 connectors
, we just can't get the sub d connector soldered good enough for the build its frustrating mom to much. The mt30 connectors will be ugly but easier to solder I'm more concerned about the quality of soldering than looks

[Burgerman]

Awire can never really be too big electrically. But will it fit connector and look neat etc.

[Scooterman]

The 180Ah 16 cell lithium pack it my scooter has gone kaput.

It's so annoying but one of them things. I have to leave the scooter on my front path as it's too big to bring indoors. But because I had a recent bout of ill health (ischeamic stroke), the scooter sort of got forgotten about. And I initially I didn't think I'd be riding it again.

When I did finally uncovere it the packs volts had dropped down about 4 volts!

It's such a shame as they were good cells (EVE 90Ah). But I had a few years use out of them, and many 1000s of miles.

The scooter has had a hard life and I did think about scrapping it, but I know I'll miss it in the summer. So I've decided to replace the pack.

Flicking through this thread I think I saw somewhere Shirley saying EVE cells aren't so good nowadays? And also the M4 threads of the 105Ah are a nightmare? But I guess they could be drilled and tapped M6 but I imagine you need a pillar drill to that properly.

Also somewhere further back a user called Fishingjunky (I think?) mentioned about lithium cells with welded terminal lugs? That sounds like a good idea. It would make the pack taller I imagine but if you've got the headroom that doesn't matter.

I've had a browse on Aliexpress cos I think Shirley said CALT cells were good? Is that a brand name?

On hindsight I should have hooked this up to the scooter and put it on the floor just inside the front door. I made it some time ago and you can set and upper and lower voltage threshold to give an audible warning. I had all the bits kicking around apart from the electronic board. It was cheap to make, but no much point if I forget to use

[Burgerman]

CALB?

[Scooterman]

CALB?

That rings a bell

I got it wrong it was CATL not CALT

Do not use those EVE_105 cells..
Their internal resistance will turn bad for no reason.

M4 thread hole made me crazy.

Learnt a lesson the hard way.

Buy CATL.

LiFePO4 for Shanghai made TESLA . Will get 8 of below for my Storm4 Xplore .

[Scooterman]

Sorry I can't remember how to insert a URL properly

https://www.aliexpress.com/wholesale?ca ... tl+lifepo4

[fishinjunky]

Sorry I can't remember how to insert a URL properly

https://www.aliexpress.com/wholesale?ca ... tl+lifepo4

this is where i purchased my 8 x 200ah cells. The lady was very helpful and responsive and easy to work with. The cells were grade A and tested full cap and correct IR. They have m6 welded studs

contact email for the lady
annette_ou@yabohybridbattery.com

listing for the cells i purchased
https://yabopower.en.alibaba.com/produc ... 755baSFmSp

[shirley_hkg]

When I did finally uncovere it the packs volts had dropped down about 4 volts!

It's such a shame as they were good cells (EVE 90Ah).

Did you try to recharge them ?

No way to salvage them ?

[Scooterman]

this is where i purchased my 8 x 200ah cells. The lady was very helpful and responsive and easy to work with. The cells were grade A and tested full cap and correct IR. They have m6 welded studs

contact email for the lady
annette_ou@yabohybridbattery.com

listing for the cells i purchased
https://yabopower.en.alibaba.com/produc ... 755baSFmSp

Thanks FJ I appreciate that I shall have an investigate

Did you try to recharge them ?

No way to salvage them ?

Hi Shirley, I tried charging them a couple of times but the PL8 tripped out twice and seeing as Revolectrix are I was worried about damaging the PL8.

Might I be able to recover them a little bit by just using the ZXD 2400 PSU. You know by slowly increasing the volts or something? They're so flat that the scooter won't even power on. The only thing that works is the dash mounted digital volt meter I wired directly across the pack to monitor the pack voltage while riding.

BM have you ever tried to recover dead lithium cells? I think you've tried with lead acids haven't you? It would be useful if they could be recovered just enough to move the scooter without me sitting on it. It's heavy to push around manually