Sinopoly Cells - Info -

[Burgerman]

Connectors are easy. Just loops of cable with a ring terminal at each end. 7 needed.

[shirley_hkg]

If i understand correctly - 90ah Cell rated at 2C - that means it will do constant discharge 180A - maybe more peak - but forget peak for now -
if you used 16 of those 90ah Cells at 2C rated - then it a bit more than borderline min. for our chairs at 360A

if this is correct - you can use a 2C cell if 90ah and using 16 of them ? this would be OK ?


Now of course if a 90ah Cell at 3C is used - would be much better at 270A for 90ah Cell at 3C

and of course you would use 16 Cells giving 180ah of battery at 540A discharge rate ? is that correct ?


i am curious to know because i do find many 90ah Cells but are 2C rated - which is still ok if the above figures and my understanding is correct .

i founds some 90ah Cells at 5C - which would be great but too tall at 280mm -

Draining all 180Ah of these 2C cells in an hour is phenomenal for a wheelchair .
Please let me know what stocK chair had survived such abusive use .

Yet , it's 1C still .

So what's the meaning of this C rate discussion lingers ?

[Burgerman]

Because many chairs can take 200A or more from the battery at times such as climbing a slope as you accelerate. Measured. Its not a matter of in 1 hour. Its a matter of intermittently for 3 to 5 seconds. Or 150A for 15 secs or so.

Measure battery current as you turn left/right on your own brushless chair. It will be 200A.

[elryko1992]

the new cells i just purchased - if they are not lying to me about the specs - its 5C - 60ah Cells - thats great -

i really wont know anyway - i will make it - and use as an ADD ON and thats it - i am sure they will give me some more range and last many years - this chair wont be used as much -

i may have to make connectors with wires - dont think i am getting any - i asked for them but they said they will try - so means they dont have them and may not get -

Expresso when you build your new cells make photo to see the steps if you want like a tutorial i want to see, when my MK is gone i want to buy this cells 60AH.

[expresso]

the new cells i just purchased - if they are not lying to me about the specs - its 5C - 60ah Cells - thats great -

i really wont know anyway - i will make it - and use as an ADD ON and thats it - i am sure they will give me some more range and last many years - this chair wont be used as much -

i may have to make connectors with wires - dont think i am getting any - i asked for them but they said they will try - so means they dont have them and may not get -

Expresso when you build your new cells make photo to see the steps if you want like a tutorial i want to see, when my MK is gone i want to buy this cells 60AH.

Sure no problem - i was thinking of that also - take it slow and try to make it simple steps - with pictures - will try to make it simple to understand and easy to follow with pictures step by step -

if you used this 60ah Cell for the whole chair - you would have 120Ah pack - 16 of them - the seller has been helpful and making an effort to make me the connectors - hopefully they work out - i should expect this order sometime in July if all goes well - free shipping takes up to 36 days - maybe sooner - they havnt shipped yet

[expresso]

Connectors are easy. Just loops of cable with a ring terminal at each end. 7 needed.

yes if i have to - thats was the idea - But turns out they are making an effort to make me the connectors - - so with luck - i may just get them - i asked to make the holes a bit larger for wiggle room - will add maybe .05mm sheet of silicone between each Cell - or 1mm - not sure - since i do want to keep it compact as much as i can

if i did my math - 36mm is the max thickness to fit in my famous plastic shoe box i use

only this time - i hope to be able to seal the lid on it - cut a opening in the middle to snake the charge cable and ADD ON connector outside with the lid closed - if all goes well - will to to wrap it like snaker did - rice cake style - wont be as good as his for sure

[Burgerman]

Now I feel hungry again.

[Gnomatic]

Haven't replied me about shipping to US yet .

Shipping to UK , USA , AUSTRALIA are OK. Same rates .

Thanks for checking, shirley!

I'm interested, in cells like this

https://item.taobao.com/item.htm?spm=a2 ... =14#detail

or this .....

https://item.taobao.com/item.htm?spm=a2 ... =14#detail

I'm not in a hurry. But can order anytime, whatever works for you. Thanks!

[shirley_hkg]

You must be prepared and willing to take a risk . You are gonna be the first crab-eater .

[Burgerman]

[elryko1992]

the new cells i just purchased - if they are not lying to me about the specs - its 5C - 60ah Cells - thats great -

i really wont know anyway - i will make it - and use as an ADD ON and thats it - i am sure they will give me some more range and last many years - this chair wont be used as much -

i may have to make connectors with wires - dont think i am getting any - i asked for them but they said they will try - so means they dont have them and may not get -

Expresso when you build your new cells make photo to see the steps if you want like a tutorial i want to see, when my MK is gone i want to buy this cells 60AH.

Sure no problem - i was thinking of that also - take it slow and try to make it simple steps - with pictures - will try to make it simple to understand and easy to follow with pictures step by step -

if you used this 60ah Cell for the whole chair - you would have 120Ah pack - 16 of them - the seller has been helpful and making an effort to make me the connectors - hopefully they work out - i should expect this order sometime in July if all goes well - free shipping takes up to 36 days - maybe sooner - they havnt shipped yet

ok good i waiting! Thanks!

[Gnomatic]

You must be prepared and willing to take a risk . You are gonna be the first crab-eater .

I like crab cakes.

[Gnomatic]

shirley let me know when you are willing to purchase and ship some battery cells. I will pay. Like these you posted earlier in this thread. Or other if better if you know.

https://item.taobao.com/item.htm?spm=a2 ... =14#detail

I'm in no hurry. happy to wait for good crab.

[shirley_hkg]

shirley let me know when you are willing to purchase and ship some battery cells. I will pay.

Check PM .

[Furio]

Hi all,

Today completed assembly of 8 nos. 120Ah cells into a pack. I followed snaker's mode of "Rice pack",though not so perfect. Used 1mm silicone sheet (cheap and quality in India)and glass fiber tape for cricket bats.

https://www.zenithrubberstore.com/shop/ ... ansculent/

I would like BM to give a preset for charging the set.

Furio.

[expresso]

Hi all,

Today completed assembly of 8 nos. 120Ah cells into a pack. I followed snaker's mode of "Rice pack",though not so perfect. Used 1mm silicone sheet (cheap and quality in India)and glass fiber tape for cricket bats.

https://www.zenithrubberstore.com/shop/ ... ansculent/

I would like BM to give a preset for charging the set.

Furio.

Nice - Snaker is on to something - i plan to do the same thing and try the Rice Cake wrap also - mines wont be as good as his or yours - looks good

[Burgerman]

Single cell and 8 cells.

[Gnomatic]

Just for example, if you take one of those 120A cells that is fully charged, and discharge it @10A with a PL8 down to 2.9v - at that point, what would the % of remaining capacity be, roughly?

[Burgerman]

About 10%? VERY roughly. Because of resistance that voltage point comes earlier at high discharge rates. And later at low rates. To measure full capacity you set a CC discharge with a 2.5V CV low current end point say 0,1C. Will that damage a cell? It may, or may not.

Max rated capacity at 100% is when its down to a dangerously low level.

[Burgerman]

With ead, you can take more than the batteries capacity from it. Ie you can go past 100Ah from a 100Ah battery. Its voltage drops to 9 or maybe 6 volts. That does a little damage but you can recharge and get back maybe 97% of what you had before.

With lithium you cause a lot of damage going below 2.5V. Or above 3.65V per cell. Theres no actual figure. They dont much like below about 2.7, or above about 3.5V. And dropping to 2.0V under load once or twice may not hurt if you either. So its always best to just keep away from each end.

If you are a manufacturer you will charge to 3.65V, and discharge to 2V to measure ultimate capacity. But YOU should not! Althought thats exactly what a BMS does. Or much worse!

[Burgerman]

Its like this... ORANGE bits hurt the battery.

and...

LITHIUM ENERGY USABLE AT SLOW AND FAST DISCHARGE RATES (if you want the cell to last avoid orange bits!!!)

LEAD ENERGY USABLE AT SLOW AND FAST DISCHARGE RATES (if you dont want to kill it, avoid orange bits!)
Remember we can set off at 8mph, we have at best 16 miles range. Thats 2 hours. Look at the 2 hour rate...

LOOK AT THIS VERY CAREFULLY. IT EXPLAINS THE BIG DIFFERENCE WE SEE WITH LITHIUM ESP ON OFF ROAD OR FASTER CHAIRS.
Charts thanks to Victron Energy.

[expresso]

With ead, you can take more than the batteries capacity from it. Ie you can go past 100Ah from a 100Ah battery. Its voltage drops to 9 or maybe 6 volts. That does a little damage but you can recharge and get back maybe 97% of what you had before.

With lithium you cause a lot of damage going below 2.5V. Or above 3.65V per cell. Theres no actual figure. They dont much like below about 2.7, or above about 3.5V. And dropping to 2.0V under load once or twice may not hurt if you either. So its always best to just keep away from each end.

If you are a manufacturer you will charge to 3.65V, and discharge to 2V to measure ultimate capacity. But YOU should not! Althought thats exactly what a BMS does. Or much worse!

BM - the presets you made for me - and i been using since day one - works fine but they are all set to go up to 3.6V - is that Ok or should they be lowered ?

Only the Combined Chair preset is set at 3.525V because of the Lead -

[Burgerman]

Initial few charges must be at 3.60 or even 3.65 volts.
After its all balanced and behaving, you can lower that to 3.55V which is kinder. But it will take about 15% longer at CV to charge/balance.

So up to you. I use 3.55 mostly. We are already at 3.60V and the manufacturer states 3.65V. And the PL8 controls voltage well. So already kind. So unlike a BMS that repeatedly bounces cells over 3.7 or more for many hours we are already being nice to them.

You can charge at 3.50V if you want. It will still be full in the end. But slower to end charge and slower to balance, and balance achieved isnt quite as accurate. As in the voltage will tend to drift slightly more after the charge ends.

So the choice is yours!

Only the Combined Chair preset is set at 3.525V because of the Lead -

And also because its held at 3.525 for for hours because thats what the lead wants.

[expresso]

Ok - i understand the Combined part - lead etc, and reason to charge at the lower volt for that chair - i only brought it up because i notice you say it alot about keeping it below 3.6V and my presets are all 3.6V

i think i leave it alone its been working fine and like you said - its already lower and the PL 8 does a good job at keeping it accurate - and ends faster - better balance etc,

maybe i try it once or twice at 3.55V to see how much longer it would take - since it will be about another month before i get the chair repaired -

i just got my Cells in today - will check them later - fingers crossed

[shirley_hkg]

Found this EVE-LF105 , same size as the 90A counterpart , but 105Ah . @£32

[Burgerman]

MEANING that you can fit 210Ah in place of lead, provided that you have JUST 4MM mm extra width available over a grp24 battery.

The math:
Cells are in mm:
130.3
37
200

37 x 8 = 296
37 x 4 = 148

We have a 240mm tall box. With 260 (or more) x 340 (or more although this way not an issue)
Arranged as
||||||||
||||||||
2 side by side is 260.6 (plus 3mm insulation from 1mm sheet so 263.6 total)
8 deep gives 296 (plus 9mm insulation so 305 total)

So with careful measuring it might just fit 16 cells.
210Ah in place of 74 (45 to 50 usable) So 5 to 6 times stock range. For £512

HOW MUCH will this cost to ship to UK in pounds for 16 cells and a huge 210Ah pack?
Thanks!

[Gnomatic]

I'd be very interested in those cells, but they won't fit in my chair's battery area.

I'm still thinking of taking my chances on a set of these .....

viewtopic.php?f=2&t=7766&start=80#p118296

[Burgerman]

>>>I'd be very interested in those cells, but they won't fit in my chair's battery area.

Are you very sure? Because I think they will fit my (returned) storm, and the new salsa, and definitely the BM2/3 chairs. And the F55s, and the storm 3 in my garage.

They will fit any place a grp 24 battery like the MK will, as long as you have literally a couple of mm (3.6) clearance to slide in an MK longest side. Most chairs actually do. Make up a 263.6 x 309mm box, 210mm tall to allow for cables. If it will fit, so will these cells.

They are each 130 wide, So 2 is the same as an MK. the ones you link to are 135 wide. So need to be turned around. And then you get 150Ah rather than 210Ah with wasted space on 4 sides.

[ICEUK]

I would be very interested too, I will measure my.groove battery box. My lead batteries are fit for the tip.

[foghornleghorn]

Add me to the very interested list as well.

I'm going to get a second opinion on last weeks measuring as it came to 260 wide. If it is only that much, looking at the exploded parts diagram I may be able to have the battery tray cut and widened without affecting the motors moving up and down but needs someone to take the chair apart again to check.