PINNED - Lithium battery conversion/info

[fishinjunky]

When checking the capacity of a single 200ah cell. Do I discharge down to 2.9v after charging to 3.65v for the first charge. Then charge to 3.60v and take note of the mah put back in. How long does it take to discharge a single 200ah cell from 3.65v to 2.9v with the ICharger using self discharge feature I wonder?

To use regenerative discharge feature I think you have to use a battery powe supply or can I use my ac to dc psu?

[Burgerman]

Charge to 3.600v. And more important than the volts, charge until current falls to a very low level. Like 1/500th to 1000th of C.

Then discharge to 2.9v. Theres still maybe 2% remaining. But dont risk damage to cells for that last bit. READ OFF WHAT CAME OUT. Not what you put back...

To use regenerative discharge feature I think you have to use a battery powe supply

Yes...

Your power suppply doesent have anywhere to put that energy. So smoke...
I put it back into my solar battery bank. And the solar inverter is a "grid tie" device, and it puts it back into the wall... Dont ask.

[fishinjunky]

Charge to 3.600v. And more important than the volts, charge until current falls to a very low level. Like 1/500th to 1000th of C.

Then discharge to 2.9v. Theres still maybe 2% remaining. But dont risk damage to cells for that last bit. READ OFF WHAT CAME OUT. Not what you put back...

To use regenerative discharge feature I think you have to use a battery powe supply

Yes...

Your power suppply doesent have anywhere to put that energy. So smoke...
I put it back into my solar battery bank. And the solar inverter is a "grid tie" device, and it puts it back into the wall... Dont ask.

Thanks,
When you say 1/500 to 1000th of C is that 1/500 to 1000th of the 200ah capacity or 1/500 to 1000th of the current at 40amps ?

After reading the manual I think it will only allow the discharge voltage to be set down to 3.0v but I'm not sure

[Burgerman]

When you say 1/500 to 1000th of C

C = battery capacity. So 1000th of a 70Ah battery would be 70mA. A 500th C would be 140mA. Some batteries may never reach this. So stop after an hour (2 MAX) at CV with lithium. Or 8 (to 12 max gel) hours at CV with lead.

With lithium you want to aim for CV + balance complete + 20 mins in regular use. That may mean reducing or increasing actual termination current to make this happen. Only need to soak at CV to 1000th C or a couple of hours CV if its first charge, or capacity testing.

[fishinjunky]

My cells have arrived they look great all 3.2vv qr code looks good, no bulging. I'm going to set the charger up an do some charging and cap testing tomorrow.

[expresso]

My cells have arrived they look great all 3.2vv qr code looks good, no bulging. I'm going to set the charger up an do some charging and cap testing tomorrow.

nice - take some pictures of them - mines wont arrive till March - haha - i didnt need them ASAP - but if i did -its worth paying extra for fast 2 weeks shipping - mines is more like 2 months or more -

[fishinjunky]

Got the iCharger all set up today took about 5mins super easy after all your guys help. I set up 1s and. 8s profiles for charging and discharging. I took notes of all settings that were recommended by you guys.. so I had that to go by. Tomorrow I'm going to start charging an discharging individual cells I'll post pics. But so far I'm very happy with the investment

[fishinjunky]

In the charger I select life for charging lifepo4? Not lipo

[expresso]

if there is a LIFE setting - i would use that one for sure -

but wait to hear from others BM etc, who may know better -

LifePo4 - or Life - should be 3.2V would give you an indication its the right one

the others would be 3.7V or 4.2V - you dont want those

[Burgerman]

Yes. Its just short for lifepo4

[fishinjunky]

Also which of these settings would I choose ‽

1. End current ON, detect balance OFF
2. End current OFF, detect balance ON
3.End current OR detect balance
4. End current AND detect balance

[Burgerman]

4

You want it to wait 3 hours in the event it needs it or longer right?
You dont want it to end as soon as its balanced and not fully charged right? So both. 4.

IN the event it never reaches the termination current, you want a 4 or 8 hour CV time limit. Adding too. Once INITIAL charge and balance has completed. That might take longer.

[fishinjunky]

4

You want it to wait 3 hours in the event it needs it or longer right?
You dont want it to end as soon as its balanced and not fully charged right? So both. 4.

IN the event it never reaches the termination current, you want a 4 or 8 hour CV time limit. Adding too. Once INITIAL charge and balance has completed. That might take longer.

Thanks

So it's either it reaches the termination current or time limit of 4 hours c/v after initial charge, which ever occurs first

[Burgerman]

Yes as long as its also balanced hopefully. If not the 4 hour limit will stop the charge/balance.

[fishinjunky]

What would be better a fuse or the existing breaker on the power cable of my chair?
And what size and type of fuse would I use?
If you look at the picture you can see how big the breaker is and it may not fit with the lithium cells. Could I replace it with a fuse and larger diameter cabble?

[swalker]

I used a circuit breaker (which can be reset) and mounted it where it could be easily reset if needed.

Of course you could use an appropriate fuse, but if the fuse blows, you will be stuck until it can be replaced.

Steve

[expresso]

i had those thoughs also - worried about a fuse -

but they all come fused from the start - and 80A is the common size fuse - dont want to jinx myself - never blew a fuse before ever

i did use a breaker on my first pack chair - 100A its under my seat in the front - the idea was it can be reset if something - i still cant do it - but anyone else would be fine

never had to -

now i have a fuse on my new chair 125A - no room for a breaker inside the battery section - if i had to change it to a breaker - i have to run a longer wire outside to the front of the chair and mount it there - i hope the 125A fuse if fine -

i did another pack for a friend same thing 125A fuse -

you making me worry now - i may carry a extra fuse and tools to have someone replace if if worst case - would be a pain to explain but can be done by some one else

have you ever blew a fuse before - ? swalker

[Burgerman]

If you ever blow a fuse it is at times when you take maximum amps. I know I can blow 80A fuses in literally the first time I attempt to draw a lot of current. When do I draw the most Amps? I CANT destroy 100A fuses on demand.

So a 125A fuse is definitely adequate and safe. So I always fit 150A fuses to every chair KNOWING that its got at least a 50% extra above what I can do. And I know too that this is a safe thing to do as the fuse is only there to protect the cables. And that the fuse is definitely going to fail before the cables.


In testing, measuring as I abuse the chair PROGRAMMING determines the maximum "pull" or the maximum Amps that the chair can pull from the battery. If your chair is programmed to have 100% turn Acceleration. And has 100% forward Acceleration. And has the motor compensation set to the very highest "jumpy" limit then your chair puts the max possible load onto the battery. If not then you wont get near the high currents that blows fuses. My chairs are all set in the most agressive way humanly possible! Does your chair behave like this? www.wheelchairdriver.com/control.mp4
If not then you dont stand any chance of blowing a 100A fuse.
For the sake of being super sure, a 125 or even better a 150A fuse absolutely garantees this will never happen. In the EU most new R-Net chairs COME with 150A fuses.

Only on 3 occasions does max current state occur. I know because I measure these things on many occasions. On MAX acceleration at 100% as in the vid above. When doing a RAPID turn in place on say heavy carpet with rear drive chairs. And when accelerating from zero to max speed when accelerating up a slope at full stick. And only is the programming is set as explained above.

To be absolutely super garanteed that the fuse never blows, fit a 150A one. It is still small enough to do the job of cable protection. And you will never blow this. And its what sunrise now fit anyway. Fit it and forget about it forever.

[fishinjunky]

If you ever blow a fuse it is at times when you take maximum amps. I know I can blow 80A fuses in literally the first time I attempt to draw a lot of current. When do I draw the most Amps? I CANT destroy 100A fuses on demand.

So a 125A fuse is definitely adequate and safe. So I always fit 150A fuses to every chair KNOWING that its got at least a 50% extra above what I can do. And I know too that this is a safe thing to do as the fuse is only there to protect the cables. And that the fuse is definitely going to fail before the cables.


In testing, measuring as I abuse the chair PROGRAMMING determines the maximum "pull" or the maximum Amps that the chair can pull from the battery. If your chair is programmed to have 100% turn Acceleration. And has 100% forward Acceleration. And has the motor compensation set to the very highest "jumpy" limit then your chair puts the max possible load onto the battery. If not then you wont get near the high currents that blows fuses. My chairs are all set in the most agressive way humanly possible! Does your chair behave like this? http://www.wheelchairdriver.com/control.mp4
If not then you dont stand any chance of blowing a 100A fuse.
For the sake of being super sure, a 125 or even better a 150A fuse absolutely garantees this will never happen. In the EU most new R-Net chairs COME with 150A fuses.

Only on 3 occasions does max current state occur. I know because I measure these things on many occasions. On MAX acceleration at 100% as in the vid above. When doing a RAPID turn in place on say heavy carpet with rear drive chairs. And when accelerating from zero to max speed when accelerating up a slope at full stick. And only is the programming is set as explained above.

To be absolutely super garanteed that the fuse never blows, fit a 150A one. It is still small enough to do the job of cable protection. And you will never blow this. And its what sunrise now fit anyway. Fit it and forget about it forever.

I think I may do a 150 amp mini anl fuse.
Is the only real difference between a fuse and breaker the convenience of flipping a switch?

[fishinjunky]

Here's a picture of the iCharger 4010duo, 24v 69amp psu, and one of the eight 200ah cells.
My future setup is going to be the new iCharger dx8 duo coming out ( its can balance up to 4amps in sync mode) and a Shirley psu.
The cells were packaged really well.

[fishinjunky]

200ah cell

[fishinjunky]

200ah cell

[fishinjunky]

200ah cells

[expresso]

look nice - if the Capacity checks out - we got a winner

BM - over there is different than here -- so far all the chairs i seen - rnet 120A sunrise chairs - all had 80A fuse

if they add a 150A fuse there - they dont here - my new sunrise chair had 80A - my friends same chair 80A also

i have 125A fuse now and same for my friends chair -

100A breaker on my other sunrise - so far so good - no issues

if i do it again - maybe i get a 150A fuse to be xtra sure

[Burgerman]

Becase all your chairs over there are years old. Sunrise realsed that a 150A one is safer from blowing and also adequate protection.

I bought a "tango" battery loom on ebay the other day. Its not even a heavy chair and uses the 90A VR2 as far as I know. It also had a 150 fuse as stock.

I think I may do a 150 amp mini anl fuse.
Is the only real difference between a fuse and breaker the convenience of flipping a switch?

Not really. The breakers tend to get "weak" over time as the heat affects the bimetalic strip. It pops sooner. And the contacts oxydse and heat up the bimetalic strip at lower current. Fuses are very much more stable. And smaller, cheaper, lighter, and if the right size will never blow unless an actual short circuit for some reason.

[expresso]

i just got my new chair less than a year ago - 80A fuse sunrise

120A Rnet - high speed motors

[Burgerman]

Well if I programed that chair so it went like mine do it will blow in 10 seconds of playing aound.
I can blow 80A fuses every time in seconds. With the old 100A pilot plus! If you leave it all soggy and unresponsive it will never blow.

[shirley_hkg]

https://www.wheelchairdriver.com/board/ ... start=6060


Having done a set a while back , I have my own set of the CATL 230Ah cells.


BMS & PL8 ready .

[shirley_hkg]

I bought only 8 cells withoue any spare , so it'd be unnecessary to do cell matching / screening at all.
Hook it up and charge directly.

My PL8 can't read cells 2,3 correctly , so this initial charge and balance will be using BMS and a power supply .

Cells came in with unknow SOC, but they did read 26.19V when assembled. I am quite surprised that ZXD2400 recorded 190Ah was put into the pack for the first charge , excluding all balance wasted. Cell capacity seems good.

Dsub is to feed PL8 for monitoring only.

[shirley_hkg]

I set the charge volt a bit lower and raised it to 3.6V when it is partially balanced, to avoid prolonged exposure to over voltage of the high cells .

My PL8 cannot read cells 2&3 correctly. They should read as the average of their own.

Glad to have alternatives , when PL8 is impossible.