PINNED - Lithium battery conversion/info

[Burgerman]

Keep posting voltage graphs and Ah.

[terry2]

Keep posting voltage graphs and Ah.

For some reason the graph only started 19 hours ago.

[Burgerman]

Computer went to sleep? Or USB did. Or something. Keep going.

[terry2]

Computer went to sleep? Or USB did. Or something. Keep going.

Most likely. another graph. Not long to go now

[Scooterman]

It’ll finish any minute now Terry. See how steep the graph is dropping

[terry2]

It’ll finish any minute now Terry. See how steep the graph is dropping

Yep

The lowest cells is Cell one 3.108V

I wonder how many amps I will really get out of the stated 176Ah

[terry2]

All done

[expresso]

very nice you got what i expected - which is great - alot of AH you have there 168ah - - our of 176ah spec. its pretty good - less than 10ah difference which i would consider great - its a pattern i been seeing with all these Cells - so far - 3 sets of Cells -- all showed the same very similar -

i would say what ever Cell you find - what ever Spec they rate it at - just remove 10ah and the Cells should give you no less than the rated spec minus 10ah - i would consider that very good - you should have nothing to worry about - if anything - then its the connections

how long did it take 2 days nights ?

[terry2]

very nice you got what i expected - which is great - alot of AH you have there 168ah - - our of 176ah spec. its pretty good - less than 10ah difference which i would consider great - its a pattern i been seeing with all these Cells - so far - 3 sets of Cells -- all showed the same very similar -

i would say what ever Cell you find - what ever Spec they rate it at - just remove 10ah and the Cells should give you no less than the rated spec minus 10ah - i would consider that very good - you should have nothing to worry about - if anything - then its the connections

how long did it take 2 days nights ?

45 hours in total

Now I am going to recharge them up ready.

And you are right. These cells we are getting are awesome.

[expresso]

i had to return 100ah Cells i received damaged - but i managed to test one and was happy with the results - if all of them tested the same - would be the best you can get at the moment - Cells were very clean new looking - glad the seller is doing a good job with this and fedex took them on monday - so its out of my hands - just wait now -

i managed to test fit them in my battery tray - and i am pretty sure i can fit 16 - so when this is resolved - i will get an extra 8 along with the 8 i paid for and take my time making a good solid 200ah pack over the winter - no rush - no chair yet to use them in - i just love the size of them makes it work and cost also very good -

if all good i should get 180ah out of these cells -

[terry2]

i had to return 100ah Cells i received damaged - but i managed to test one and was happy with the results - if all of them tested the same - would be the best you can get at the moment - Cells were very clean new looking - glad the seller is doing a good job with this and fedex took them on monday - so its out of my hands - just wait now -

i managed to test fit them in my battery tray - and i am pretty sure i can fit 16 - so when this is resolved - i will get an extra 8 along with the 8 i paid for and take my time making a good solid 200ah pack over the winter - no rush - no chair yet to use them in - i just love the size of them makes it work and cost also very good -

if all good i should get 180ah out of these cells -

"200AMP"

This turning in to, who can get the biggest cells in their chair

I hate the aluminium threads in the cells

[expresso]

i dont like the trends either to screw them down - thats the issue i had with the 80ah pack - 4 of them were a bit stripped - not good connections - i redid it and added loackwashers to those with a longer screw - i hope that works - or else - have to redo it all with locktite and lockwashers again thats all i can do -

[Scooterman]

I hate the aluminium threads in the cells

Aluminium is a good conductor.

I guess they're made that way so it's easy to link many cells with bus bars for huge solar or marine (luxury yaught) lifepo4 packs?

Sorry, i can't spell yaught

[Gnomatic]

BM, how many Nm of torque would you recommend for tightening the terminal bolts on these prismatic cells with aluminum threads?

[expresso]

i was using the same wrench used on the headways at 5Nm but i was still a bit afraid to keep tighten before it reached it on some of them - i would think its safe at 5Nm but i believe i read once someone else was stated at 8 for that cell -
i like to know also

[terry2]

I am recharging my pack and I noticed that 1 thread is half stripped.
Can these cells be helicoid?

[expresso]

I am recharging my pack and I noticed that 1 thread is half stripped.
Can these cells be helicoid?

check them all - i found 4 of them on my pack that way - that could and will cause problems - mines worked fine a short while then when going to recharge - it wouldnt see half the pack - pl8 error etc, - and it turned out to be the connections only - adding locktite makes me worry also because it will get inside and that can make bad connection also if too much is used - as bad as it may sound - i think a touch of locktite only very little but lockwashers also -

what size screw did you use - how long - i ended up using 10mm on some with the lockwashers - 8mm on the others with out - depends how thick our ring connectors are also - if i have to redo it - i would use all lockwashers - locktite just a touch and 10mm long - and screw down good enough - this will depend also on the cells - can be different for mines - depends how deep they make the trend - its a learning process with these kind of cells -

[terry2]

I am recharging my pack and I noticed that 1 thread is half stripped.
Can these cells be helicoid?

check them all - i found 4 of them on my pack that way - that could and will cause problems - mines worked fine a short while then when going to recharge - it wouldnt see half the pack - pl8 error etc, - and it turned out to be the connections only - adding locktite makes me worry also because it will get inside and that can make bad connection also if too much is used - as bad as it may sound - i think a touch of locktite only very little but lockwashers also -

what size screw did you use - how long - i ended up using 10mm on some with the lockwashers - 8mm on the others with out - depends how thick our ring connectors are also - if i have to redo it - i would use all lockwashers - locktite just a touch and 10mm long - and screw down good enough - this will depend also on the cells - can be different for mines - depends how deep they make the trend - its a learning process with these kind of cells -

It's just the one.
Stripped half way down. I don't think that these will be up to drilling and putting a helicoil in.
I have some 6mm grub screws and will Loctite that it.

[expresso]

check to be sure its just the one - i found 3 at first and then when i double checked - found one more which i though was good before - while you have it out or working it on - just takes a little time - or else if you feel its good - dont worry - if you have the room to add the grub screws - i think thats good because then you dont have to touch it again - locktite it down and then screw down without worry -

i wont have the room when i do mines - - lets see what BM suggests - i dont want to suggest something that wont be good - one set of Cells i have 60ah - has top posts that are steel and you screw down over them - Not in them like we have now - those i would love - but take up too much room - cant use too tall

you can try some locktite now and lockwasher with a longer screw on that one cell you feel its loose - i used a 10mm long - and it seems to lock down nicely with a lockwasher - no locktite this time around. will it hold - only time will tell me - i only used it twice since i fixed it -

[terry2]

check to be sure its just the one - i found 3 at first and then when i double checked - found one more which i though was good before - while you have it out or working it on - just takes a little time - or else if you feel its good - dont worry - if you have the room to add the grub screws - i think thats good because then you dont have to touch it again - locktite it down and then screw down without worry -

i wont have the room when i do mines - - lets see what BM suggests - i dont want to suggest something that wont be good - one set of Cells i have 60ah - has top posts that are steel and you screw down over them - Not in them like we have now - those i would love - but take up too much room - cant use too tall

you can try some locktite now and lockwasher with a longer screw on that one cell you feel its loose - i used a 10mm long - and it seems to lock down nicely with a lockwasher - no locktite this time around. will it hold - only time will tell me - i only used it twice since i fixed it -

The thread on my nuts are 10mm long. The whole is 14 mm long.

I have some longer ones coming. For the time being I have tightened up the nut and hot glued around and over it.
So when I close the battery, it will be pressing on the plastic top.

[expresso]

see what BM suggests - with these cells - i think its best not to keep screwing and unscrewing - its best to be careful and try to do it once and leave it - you can try a 12mm long - it depends how much you have under it also - ring terminals etc, or take the rings you will add to a cell and stick the screw thur them to see how much of it is left over which will actually screw in the cell itself -

if you feel theres not enough exposed - then try a longer screw - just test it to see - without screwing it in the cell - you know if you screw them in just once at an angle it will strip it - its very important to start off correctly when you screw it down - if it feels too hard - it may be angled and stripping it - i will try the screws i received first next time i do another one - or at least i can measure them to know - if i want to use a different one - but same length -

there must be a way to fix these if they did get stripped enough - but i dont know how and would be afraid to use a drill - maybe something by hand slowly - i rather not have to do that

[snaker]

@terry2: the discharge graph of your park is perfect. Why do not you enjoy it by driving a 'mad' trip until you or your pack is completely drained

[terry2]

I hate the aluminium threads in the cells

Aluminium is a good conductor.

I guess they're made that way so it's easy to link many cells with bus bars for huge solar or marine (luxury yaught) lifepo4 packs?

Sorry, i can't spell yaught

Yes Aluminium is a good conductor. But the threads are shit.

@terry2: the discharge graph of your park is perfect. Why do not you enjoy it by driving a 'mad' trip until you or your pack is completely drained

Thanks dude.

It's to cold in the UK at the moment to do any very long trips
I did do a 15 mile trip and my 2 motors got hot .

[Burgerman]

If those threads in the cell are accurate and well made, and if not used... (abused) then you should, if the bolts are long enough not have issues.

When tightening into soft aluminium, or using those stupid solid copper bus bars links that add pressure when anything moves, or if thread is too short, or overtightened, you WILL have problems. Aluminium is weak. Loctite wont help at all.

You must inspect and take care,use quality stainless threads, that are LONG ENOUGH and ring terminals. And then tighten just enough. Dont use spring washers, wave washers, lock washers, use flat stainless washers. And FEEL when its tight. Use a torque werench if you have one but set very low. 4 Nm 2.5 to 3 ft-lb. Thats if: the threads are 1.5x the 6mm diameter. So you need 9 (to 10mm) of free thread. If the good thread is not that deep in the cell then send them back because its not adequate. If part stripped due to ham fistedness you will need to use a helicoil.

[Burgerman]

After about 3 miles the motors are as hot as they will get. Unless hills. Going up heats them up. Going down does the opposite. Going further doesent get them hotter.

[shirley_hkg]

Going to get hold some EVE-LF105 cells , directly from factory . 105Ah rated and brand new .

It has M4 threads , 6mm deep only , and recommend 8Nm.

John , do you think M4 will work ?

[Scooterman]

And remember you can always give the bolt a tweak second time around or the next day. I find that especially in soft materials that connections tend to 'settle', so it's worth going round the pack again a few hours later or the following day. And definitely after you've been foe a test run over some bumpy ground.

Also for them aluminium terminals i like using the screwdriver handle attachment on a 10mm 1/4" drive socket. I think it gives you more feel and you don't particularly need the leverage a ratchet provides. Although if you grip the ratchet head it gives you good feel.

Also i wrap metal tools in insulating tape for the batteries, i too much of a butterfingers

[terry2]

And remember you can always give the bolt a tweak second time around or the next day. I find that especially in soft materials that connections tend to 'settle', so it's worth going round the pack again a few hours later or the following day. And definitely after you've been foe a test run over some bumpy ground.

Also for them aluminium terminals i like using the screwdriver handle attachment on a 10mm 1/4" drive socket. I think it gives you more feel and you don't particularly need the leverage a ratchet provides. Although if you grip the ratchet head it gives you good feel.

Also i wrap metal tools in insulating tape for the batteries, i too much of a butterfingers

I have only a 4 inch gape going down to a 2 inch gape in my battery bay.
It's a pain to do anything, let alone these cells.

I may ask the seller if they are safe to drill. As I don't know if they was drilled\threaded before or after being put together.
If he say they was drilled after, then I'm going to helicoil the lot. No more worries

[Scooterman]

I agree ‘access’ can be a bitch (excuse moi french) on a powerchair. I’m lucky with my power chair in that it’s got a fixed seat so easy to unbolt 4 bolts and lift clear after unplugging joystick cable.

I’ve never seen or used helicoils but have heard of them. Will you go up in size, say m7 or m8? Or do you buy m6 helicoils and they fit in m6 threaded holes?

[Burgerman]

M4? Sounds dodgy! Might be OK if that aluminium alloy is hard enough. But it sounds a little small and weak to me.

Helicoils mean you end up with a M6 thread again, but it is steel/stainless steel.