PINNED - Lithium battery conversion/info

[Burgerman]

Laptop manufacturer's say to use Nyloc just once, but they really do hold for multiple re-uses. Nevertheless, adding a drop of medium loktite when using them may not be a bad idea.

Yes it is.

The nuts dont want loctite or you will loosen the stud from the battery potentially damaging the soft alloy thread when you try to undo them at some point. You MUST loctite the stud with RED LOCTITE into the cells. ONLY!

And a NYLOC nut even a used one, will NOT ever come loose on its own. Ever. Provided you dont add a spring washer. OR provided you dont used flanged nuts with a built in washer. You MUST use a normal nyloc, and a FLAT washer. Why? Because any vibration or pulling on a terminal or cable that turns the thing anti clockwise will also turn the nut! You want that to slide. Not to grip the nut. You want the nut to turn ONLY when YOU turn it.


YES - DEFINITELY NO LOCTITE!


NO!!!


NO!!!


NO!!! Esp no.


NO, NO, NO!!!

[expresso]

i have to double check mines - i did it that way - but now you got me thinking about that flat washer - if i used one or not ? cant remember now - and i have it all wrapped - in the event i didnt use the flat washer - - how bad can that be or would it cause issues ? its all done already - so not looking to take it apart now unless its really needed for sure


what do you think ?

[ICEUK]

I used a flat washer and the correct nyloc nuts u show bm. Still came loose. I put it down to being reused.

[Burgerman]

I dont. I suspect that the stud wasnt strong enough (weak thread and it has moved or partially stripped and just enough to work loose).
Because you overtightened.
Or because the stud was inadequately loctited with red loctite.
Or you tightened it inadequately and was always loose.
Or you forgot to tighten one properly.

I have reused those nuts on cars and bikes and batteries for years. You can feel that they still grip as you turn it or remove it. That resistance to free spinning is all thats required. That enough. If they come loose theres another reason. Maybe soft copper terminals are annealed and very soft. Or something too. Brass is better. Zinc plated brass is better still.

[Burgerman]

i have to double check mines - i did it that way - but now you got me thinking about that flat washer - if i used one or not ? cant remember now - and i have it all wrapped - in the event i didnt use the flat washer - - how bad can that be or would it cause issues ? its all done already - so not looking to take it apart now unless its really needed for sure


what do you think ?

The flat washer spreads the load to a larger area. It also prevents the nyloc nut turning anticlockwise if a cable gets pulled from vibration or physically as you install the battery or because its pushed by the chairs casing etc. It lets the terminal turn slightly, without the nut turning. If you are unlucky then the PL8 will tell you...

[expresso]

BM - if after i check my pack - i cant really see it good - since i got it wrapped well - i may be able to notice if i used flat washers or not - BUT if i didnt - do you think its a major thing to redo ? or can leave it alone - its fine now - not installed in a chair yet -

[Burgerman]

Who knows. It will likely be fine as long as none are knocked so loosened. Its not essential, most people do it all wrong. Never any wiser. The thing with me is I rebuilt and stripped dozens of cars, bikes, lawnmowers and engines all my life. To me what bolts, nuts and washers should be used for what seems obvious and intuitive. But not for most. Almost everything works. Some things work better than others!

You are aiming for a NEVER come loose strong stud, in a soft alloy thread. So clean and red loctite that in for good. Or it will strip out, or come loose as you trist a terminal.

You are aiming for a NUT and a washer to spread the load over a wide area, to better clamp the parts and get low resistance. So must be clean surfaces and flat washer. And you want the nut to stay in the same position, when the terminal is pulled. Use of a spring or shakeproof washer or a flange nut and that TURNS with the twisted or pulled terminal loosens the nut! You want a flat washer to allow a pulled cable to not turn the nut! The nylon insert holds it still, and the flat washer slips. And the red loctited stud cannot turn either.

You dont want loctite on the nut or your stud will turn or strip out of the battery when undoing or trying to tighten later.

[expresso]

got it - thanks - i think i am OK - leaving it as is - i didnt use Red - i used a Green locktite which is thicker than blue - it works - i had only one set screw not working well - was a bit stripped i realized - i used red on that one only since rest were all done and tightened down already - worked great since -

once installed - it wont be moving in the chair - its a very tight fit - wont have room to move at all - and cables wont be pulled either - i leave it alone then -

thanks

[daunjan]

Hey there quick question, getting battery pack from rjlithium, asking about bolts is best to get them welded or screw thread in m6 bolts?

Thanks

[shirley_hkg]

Welding is the best definitely.

Screw thread is only viable for DIYer.

[daunjan]

Thanks Shirley had to go screw thread as weld added 10mm height to 225mm. Got them ordered , gonna balance with your power supply. Just need to sort balance cables.2 weeks be in NZ. Pl8 looks like Sept 30th maybe available???

[terry2]

Hi all. Hope your all ok.

I want to charge my cells up and get them ready to go in to my chair.
Because of the chinese virus it may take 2 days for people in my bubble to help me.

So. Is it ok for me to charge each cell up and then in a day or 2, install them in my chair?

Thanks in advance.

[Burgerman]

Yes and no.

Its OK to charge each cell. And then assemble them into a pack. And then charge the pack to fully balance and be sure it all works properly. And THEN install the pack into the chair.

[terry2]

Yes and no.

Its OK to charge each cell. And then assemble them into a pack. And then charge the pack to fully balance and be sure it all works properly. And THEN install the pack into the chair.

Thanks BM.

It will be 2 packs of 4 cells. 1 pack each side of the chair.

So I will charge up the first 4 on there own. Then wrap them up to the 1st pack. Then charge and balance pack 1
And do the same for the second.

Then charge\balance the whole lot

[Burgerman]

Correct. Well you dont need to do the 2x 4s packs seperately. Just all 8. Then do a 20 to 40% DISCHARGE and followed by a full charge. Twice. So you can check for problems. Then fit.

[terry2]

Correct. Well you dont need to do the 2x 4s packs seperately. Just all 8. Then do a 20 to 40% DISCHARGE and followed by a full charge. Twice. So you can check for problems. Then fit.

Thank you.

Have you still got the PS8 file for 8S 170 AH cells?

I have the one for a single cell.Which I am using now.

[Burgerman]

http://www.wheelchairdriver.com/presets ... 4%20packs/

[terry2]

http://www.wheelchairdriver.com/presets/LiFePO4%20packs/

Thank you BM.

Just charging now.

I did have 2 sets of balancing wires. 1 for the PL8 and the other for a monitor.
All nice and neat.

But then a cat got in and messed the lot up

[7Gluk]

Hi all!
I have 2 wheelchairs:
1. EXCEL X-POWER 5, remote - Dynamic A-Series DA50-A41, charger - 4F24050 24VDC/5A, battery - 2 (serial conncted) TEV12360 12V/36A dead.
2. FS101A-46 (2014y), remote - newVSI, charger - HP8204L2 24VDC/5A, battery - LI-ION about 25V.
The 1st wheelchair works great on the battery from the 2nd.
The only question is, can LI-ION battery from 2nd wheelchair be charged in the 1st wheelchair and which of the chargers?
I just don't know where the charge controller is located - in the charger or in the remote, and how compatible the remotes are with other chargers (the pinout is the same) ...

Sorry, if offtopic...

[Burgerman]

I cant decipher that. And not enough info.

Can you post pics of batteries, chargers and connectors. And chairs. And charger details.
Can you link to a spec page or manufacturer page for each?

Are both lithium ion?
Are they 12v or 24v?

Where do the chargers connect?

[Burgerman]

https://www.aliexpress.com/item/32814144564.html

This charger is one of yours?
It can be specced to charge lead (very badly) or lithium WITH A BUILT IN BMS also badly. It depends on its firmware.

[Burgerman]

And I cant find any info on the other charger. So I doubt it is wise to swap them. The devil is in the details.

[terry2]

Just had a few beeps from my PL8 V2 then it went off while charging
The light flickers for a few seconds, then stays off....

On the charger screen it has OCP..another one fucked....
You can't even buy them...going to look for a alternative.

So I may have to change it back to normal batteries.

[Burgerman]

Sounds like the PL8 is takig more from the power supply than it can give. So you MUST configure the supply tab. Set its max amps to below what your power supply is rated at.

Set volts to 28V and lowest volts to 10...

And on another heli forum that OCP error was caused by power supply voltage spikes. Usually when turnig on the power supply. What power supply are you using?

I spoke with Howard at FMA on Tuesday and he told me what the issue was. I guess the voltage spikes were causing the problem.
I am switching to a different powersupply. Not worth the risk for me.
Thanks for the info.

[terry2]

Sounds like the PL8 is takig more from the power supply than it can give. So you MUST configure the supply tab. Set its max amps to below what your power supply is rated at.

Set volts to 28V and lowest volts to 10...

And on another heli forum that OCP error was caused by power supply voltage spikes. Usually when turnig on the power supply. What power supply are you using?

I spoke with Howard at FMA on Tuesday and he told me what the issue was. I guess the voltage spikes were causing the problem.
I am switching to a different powersupply. Not worth the risk for me.
Thanks for the info.

I already set it up 3 months ago and it was ok.

No spikes as I have 3 surge protection devices between the power supply and mains socket.

Just looking for an alternative as REVOLECTRIX has told me they have no idea when they will be back in stock.

[Burgerman]

Surge protectors at the wall/power supply make no difference. The spikes are from the electronics IN the power supply. It makes them.

Remember that others have traced this to a power supply issue with an occiloscope. Normally spikes of extremely short duration but beyond the upper allowed voltage for the PL8. Often when switching on. And I have 4 of those chargers, for almost a decade. Non failed and they get used a *lot*!

You had 2 fail. Common thing is the power supply. And so it will likely do the same on any other charger you buy. What is the power supply?

[steves1977uk]

I am still on my original PL8 from 2014 and no issues whatsoever. What order are you connecting things Terry? It's a bad idea to connect the PL8 to the pack before powering it on as this can cause the issue you describe. Also with other chargers we can't tell how well they balance and if the charging algo is optimised for LiFePO4, especially with big packs.

Steve

[terry2]

Surge protectors at the wall/power supply make no difference. The spikes are from the electronics IN the power supply. It makes them.

Remember that others have traced this to a power supply issue with an occiloscope. Normally spikes of extremely short duration but beyond the upper allowed voltage for the PL8. Often when switching on. And I have 4 of those chargers, for almost a decade. Non failed and they get used a *lot*!

You had 2 fail. Common thing is the power supply. And so it will likely do the same on any other charger you buy. What is the power supply?

My first fail was my fault.
The second was who knows...and no power supply is 100% good for anything...so those guys must have more cash then sense.

I.E I had a top of the line seasonic power supply for my PC. It died after 2 days

REVOLECTRIX GT500 for £75 sounds good.

REVOLECTRIX guy said it can do 8S and lifepo4

[terry2]

I am still on my original PL8 from 2014 and no issues whatsoever. What order are you connecting things Terry? It's a bad idea to connect the PL8 to the pack before powering it on as this can cause the issue you describe. Also with other chargers we can't tell how well they balance and if the charging algo is optimised for LiFePO4, especially with big packs.

Steve

It discharged ok, then I left it off for an hour.
Turned on the power supply\PL8, then connected to the cells. Like you told me

After an hour of charging..I heard a few beeps and that was it.

I really don't care it can tell me...as long as it does it's job..
Think I will go back to normal batteries. A lot less bother and cheaper

If they stop making these PL8s...what are you going to do?

[Burgerman]

It can.

Its got no PC software, no good templates so you will have to configure it all yourself, which I think is not actually possible and you have to use their profiles. How you going to set up the correct balance type, parameters, balance start point, and termination value? And time limits, and the balance high/low cell limit since its too low by default?

Yes it can sort of work. You wil get errors if its out of balance. And god knows at what current it will decide to terminate.

And...

I spoke with Howard at FMA on Tuesday and he told me what the issue was. I guess the voltage spikes were causing the problem.
I am switching to a different powersupply. Not worth the risk for me.
Thanks for the info.

Says that your power supply will do the same to that new charger too. What IS your power supply?