PINNED - 230Ah (245Ah certified) A grade cells Amy, Docan

[Burgerman]

I can point you at a mac version thats "fixed" latest version...

The problem there is that its on a mac!

[Burgerman]

THIS should get you the latest MAC version.
Password for the zip/rar or whatever is 123
Its all pre cracked and so just install. Well it is on windows and I think this will be the same.
You will want to block the ilustrators executable file - wherever it puts that on a mac - from all outgoing connections. Or in about 30 days it will tell you it cant register itself...
If you do block it that will never happen.


https://www.mediafire.com/file/blvkxwuq ... 6.zip/file

[jefferso]

Thanks! Will check it out.

[Burgerman]

OK. 4 weeks passed. So now about half way through the delivery wait! Go Amy!!!

And my new DJI Mini Pro 4 arrived. So many toys, so little time!
https://www.stuff.tv/review/dji-mini-4-pro-review/

I am 64, 65 soon. Still cant stop me playing with toys and projects. No wonder I am single again!

I can legally fly this from my garden, all over my town, and over people houses, traffic, etc. It does image stabilised 4K footage at 30, 60, 100fps, inc special "flat" tone ones so you can colour grade later. And has about 6 miles max range. So 1 mile is super reliable over a town or city. Uses 3 different frequencies at once and displays a HD image on your RC transmitter so you can see what it does as you fly. Its also covered in sensors that wont allow you to fly into people ir obstacles. And so pretty much uncrashable. Fun! Great hobby for a wheelchair user. Great photos too, inc raw (as .DNG images) at 48mp. Also works great at night. Take a look over your city and see whats happening!

[Burgerman]

OK some comparison maths.

MK Gel, has 44Ah that is usable at the 2 hour rate (7mph for 2 hours = 14 miles till you stop, and thats the capacity that is returned).
So: 44Ah x 12V nominal voltage is 528 watt hours (2 batteries so 1,056 watt hours total energy) that is giving approx 14 miles range.

Thats 1056 div by 14 miles or 75.42 watt hours per mile.

The 230Ah lithium I am waiting for is certified 245Ah plus some change at the 2 hour rate. And in fact the 1 hour rate! So thats 808.5 watt hours per cell. For all 8 cells thats 6,468 watt hours total energy storage. Thats 6468 div by 1056 (lead total w/h@2h rate) = 6.125 x as much range. Or if you prefer a 600% range and some spare. A huge increase over lead.

So instead of 14 miles range, we now get 6468wh div by 75.42 watt hours per mile or 85.75 miles.
But thats just me. I use a lot of watt hours (Ah) per mile compared to most users as my chair is a huge 190KG and I am pretty heavy too! And my fat tyres and low pressures eat up much more power as well as my aggressive programming. So most users will see a lot more distance than this. But 86 miles is a very long way regardless...

[Burgerman]

Tracking FINALLY! At least it says soon to be updated and its in birmingham.

And this may be useful to some.

But dont rely on this as its very much temperature and specific cell brand/etc. And the middle bit is so flat that theres no way to measure capacity by voltage.
But the full and empty ends are quite accurate! These are 4S figures. So divide by 4 for a cell voltage.

[Burgerman]

My NEW 3000 Watt ZXD Power Supply ships in a week.
Rear has XT90 + Anderson 50, mainsAC.
Front has what you see here!

0-50A and 0-60V and 120 or 240V AC automatically.
2 stage or 3 stage charging, or bench power supply.

And very cheap considering the build quality ruggedness of electronics and the fact that its a better lead charger than all wheelchair chargers that I ever tested. And I tested many. AND a perfect PL8 or hobby charger power supply.
Also in my case as a bench supply for testing/running many things like my electroplating tank or motor testing. Also posted in the 62 page ZXD THREAD. https://www.wheelchairdriver.com/board/ ... 10#p205610

[Burgerman]

And still waiting for cells!

And now for this (I changed my mind which one):

[Burgerman]

OK Amy's batteries arrived... That was a LONG wait!
Still no rush... Its winter.

Perfect packaging, lots of padded polystyrene pre-shaped moulded support. All look absolutely pristine brand new, completely flat, perfect condition etc.

All voltages were 3.2623 (+/- 0.0003V) So as close to identical as its possible to be. After 90 days in customs, shipping etc that means self disharge is low and the same across all 8 cells. So long storage unused wont be an issue with these.

Have not checked impedance yet. But expect that to be equally well matched across cells. Will find out soon.

Capacity tested 1 random cell so far, with PL8. And got 244.77Ah. (3.600V down to 2.700V) so the spec sheets claimed 245Ah with 3.65V to 2.50V is undoubtedly correct.
So far then all better than expected and better than the 230Ah claim by quite a margin. These are actually 245Ah cells.

Came with 8x thin fibreglass seperator plates, and a bunch of flexible cell connectors. And stainless nuts (that I wont use).

Thats 6x the usable energy than a set of MK 74Ah gel batteries. Or 6x the range if you prefer. For less money than lead! And with 30% less mass. With around 7 or 10x the service life. Amazing really how cheap these now are for quality cells per Ah. Which have become easier to get. At about 20% the cost of lead per mile!

[shirley_hkg]

WOW ! ! !

[Burgerman]

She says these are EV grade rather than A grade which are "better" apparently! Who knows. ut they are definitely higher capacity than it says on the tin and very closely matched if the individual spec sheets via the scanned code are correct.
But as a supplier I recommend. Probably best cells I saw. And I have built a few for others around here and for my freinds solar setup, and a tramper... And a freinds holiday home with no main AC power. So I have seen a few. AVOID aliexpress etc!

Also my carer is looking at a VW electric van. These vans are super high build quality, but solds cheap, with very low mileage used because of a stupidly small but 102S lithium ion 37kwh pack. Real world range is crap! About 46 miles of the claimes 70. So I will build him a 120S LiFePO4 addon, same cells as mine, 230 (245Ah) add on pack... This is around 380V DC nominal. So that will need a 120S BMS! How I do that I dont yet know.

But because sea shipping from china, and slow UK customs it took 2.5 months. But Docan and Amy Zheng in china (email her for a deal) is highly recommended.

[Burgerman]

For what its worth, theres a gel grp 24 battery on my floor from the salsa. Its an 80Ah one, fitted as stock. These cells, with the welded stud, (very neat and done by machine) are 5mm taller.

The lead battery has a flat top with m6 threaded holes. And this was measured with the bolts fitted. So thats a fraction under 1/4 of an inch taller. So it will fit almost any grp 24 chair. As theres always at least 1/4 inch clearance. Enough for cables and anderson connectors etc.

As for length and width, then we already know that this can be smaller than the outline of a set of grp 24 batts. We have length and width gap all around. The measurements here:

[Burgerman]

For those interested in what a genuine cell looks like.
Basically it is super clean, totally flat, no dings, dents, no oxidation, genuine etched qr code that can be cross referenced with the manufacturer and a spec sheet for that specific cell downloaded, and supplied by a genuine company with all the correct paperwork to garantee authenticity.

These cells are common. Or were for years. They can be found sold as "A grade" all over the place, such as chinese auction sites. But they are definitely not!
Some are re-covered, have new QR codes made up and attached, and are actually used, returned as faulty, very old stock, B grade meaning they were sold cheap as the manufacturers spec wasnt reached or that they have any of the following issues. Rapid self discharge rates, inconsistent (unmatched or high IR or impedance) low capacity*, etc.

According to Amy at docan, who sold me my cells, there are very few genuine EV grade cells sold as thee are usually for manufacturers, bulk buyers in the OEM industry etc. The rest are sold as B grade, or A grade which are both not as good.

Some B grade ones, are sold as lower capacity cells. So not the expected "230Ah" that the 55 x 200 x 173mm standard case size would be expected to be. So sold as 200, 210, 215, etc.

SOME A grade can reach the 230Ah expected. And are sold as A grade. These are not EV rated.

SOME sold as A / EV grade are actually really EV rated ones that generally have lower impedance, and are generally higher capacity than the rated 230Ah. In my case these cells are all supposed to reach 245Ah according to the last batch of over 1k cells. I tested just 1 so far. It was 245Ah. And EV rated cells are very closely matched in impedance, self disharge rates, capacity etc. So these are as good as it gets. These can cope with a hard life, in an EV and are the kind of cells that would stay in balance long term even with a typical crappy BMS over a long periods. Ask Docans Amy for EV rated cells...

[Burgerman]

Remember that an UNUSED NEW cell, will have a almost perfectly flat surface with no bulge. It may have a tiny amount of hollow "dip" in some places, the opposite to a bulge. But it will be almost invisible unless you hold it at the right angles in hard light to see a reflection across the surface.

This doesent garantee its brand new, but a heavily used cell will show some swelling. This happens over time with too high charge voltage, storage at max volts, charge with less than perfect balance pushing a cell too high. Its also caused when discharging at high rates. EVs can pull very high amps. This causes bulging too. The plates "gas" inside, pushing the thin plate materials apart. The case is very thin. Not much more than aluminium coke can. So it swells if the cell is overcharged, over current, over temperature.

If we fit these in a chair, and the pack is big, we wont ever pull high enough currents (amps) to cause this. A BMS or DUMB charger especially is set to the "recommended" 3.65V per cell (use 3.550V max) can cause it though.

If the intended use will pull continual high currents, (as in if the pack isnt really big enough for the job) then clamping the cells between 2 metal plates and bolting them up to stop the expansion is recommended. IF thats been done suring previous usage than even old abused cells will still be flat... So even this isnt a garantee. If the previous use was gentle, charged to a more sane voltage or if they sat for years unused. They will also still be flat...

So another test is CAPACITY. Should be at LEAST the rated capacity!
And another test is IMPEDANCE. This should on say a 230Ah cell be consistent across cells, and be 0.23mOhm according to EVE spec on a new cell.

If they pass the visual, the QR code, the flatness tests, and read a larger than rated capacity, as well as a low internal resistance (impedance) as these do, then you got the new A grade or EV grade cells you paid for!

If any of the above isnt true, you were ripped off. Which is why you should pay with a CREDIT CARD or PAYPAL for protection. An awful lot of bad, failed, used and recovered to make pretty, and other "back door" inferior cells of various types and claimed capacities come out of china.

All my cells read the same 0.21 (or 0.22)mOhm across the board. Thats low and exactly as per the manufacturers spec for EVE 230Ah EV quality cells on the spec sheet.

These cheap mOhm measuring impedance meters from cheap china use 4 wires, are very accurate. Essential to know how good your cells really are. And to determine if they are A grade, EV quality, and new.

[fishinjunky]

They look great best looking I've seen early next fall I'm going to order the same cells from them for my next pack. I'm building it next winter.

[Burgerman]

Well in my case, at least, cant fault them. Amy emailed to ask if they arrived today. She is on the ball. Delayed in UK customs a MONTH!

[Burgerman]

Actual cell data:

For what its worth, the EVE LFP230 CELLS are definitely still current and being manufactured.
How do I know?

Manufacture date (old cells bad, new cells good right?) Apart from aging being problematic they improve incrementally over time with experience, chemistry, consistency etc. I though that the 230Ah ones were end of life but plenty still around. But mine were all made same day, except one cell, made the previous day...

In 3rd week of june 24. Considering I had them a while, and that they spent 2 months shipping and another month in customs, then they must have been still hot when they loaded the boat!

[Burgerman]

MEASURED:
Cell 1 #497 3.2620V 0.22mOhm
Cell 2 #055 3.2618V 0.22mOhm
Cell 3 #497 3.2618V 0.22mOhm
Cell 4 #460 3.2623V 0.22mOhm
Cell 5 #763 3.2620V 0.22mOhm
Cell 6 #934 3.2622V 0.23mOhm (22/23 flickers)
Cell 7 #786 3.2618V 0.22mOhm
Cell 8 #353 3.2613V 0.22mOhm (22/23 flickers)

24 weeks order/shipping/customs etc.
VOLT DROP over 24 WEEKS per cell.

Cell, Shipped volts, measured volts, difference, loss of mV.
Cell 1, 3.270V - 3.2620V = 0.0080V = 8mV Loss over 6 months.
Cell 2, 3.270V - 3.2618V = 0.0082V = 8mV Loss
Cell 3, 3.270V - 3.2618V = 0.0082V = 8mV Loss
Cell 4, 3.271V - 3.2623V = 0.0087V = 9mV Loss
Cell 5, 3.271V - 3.2620V = 0.0090V = 9mV Loss
Cell 6, 3.271V - 3.2622V = 0.0088V = 9mV Loss
Cell 7, 3.271V - 3.2618V = 0.0092V = 9mV Loss
Cell 8, 3.270V - 3.2613V = 0.0087V = 9mV Loss

2mV Spread across 8 cells in 24 weeks during manu, shipping etc to today. (6 Months). So very equal self discharge rates between cells. No problem storing or re-balancing these even if stored years unattended.

[foghornleghorn]

Now you have had them a while I need to ask what capacities did you find on each cell in your own testing?

[Burgerman]

Exactly as per spec, minus around 0.3Ah compared to individual cell spec sheet above. But I am not discharging to 2.5V as specified and stop at 2.7. And charging to 3.6 initial charge not 3.65 as specified. But that makes very little difference. But I am in a 19C room. And the figures are for 25C. That makes a bigger capacity difference.

Which isnt bad considering that they are sold as 230Ah cells! This is normal on EV rated cells according to Amy. Theres around a 1.1Ah spread between the best and worst cells. But from past experience with hobby cells, the first few cycles improves capacity a tiny bit too. The lowest cells tend to improve a little more than the best ones do usually. So that 1.1Ah spread (about 0.4% capacity) should practically vanish once cycled as a pack a few times.

I think how warm my room is on each cell tested, on different days makes more difference than any actual capacity difference I measured.

As it is, I will be safe to discharge by 99.5% without the lowest cell dropping below 2.5V. So about as good as any pack I ever built or bought for hobby or chair use. Impressed by how matched they are across all important metrics. Esp IR. And SD.

Headways can get closer just because they use a lot of cells in parallel too. So the differences average out more per group.

I will be buying another set for a 2nd chair from Docans Amy once this is done and tested. But rest assured, you can buy these safely, great quality cells. Crazy long delivery times...

[fishinjunky]

BM When you finish the pack will you post pictures? I really enjoy seeing everyone's finished packs

[Burgerman]

Yep!

[Burgerman]

Currently have these from amazon

6mm hole. 10mm2 cable input, so I can solder the 8 AWG silicone wire in.

6 meters of silicone insulated 8 AWG cable. I normally use PVC insulated 10mm2 but this will do... More fragile though. Because I use it for other things too.

And for concentration so I dont blow myself up...

[foghornleghorn]

@Burgerman
Could you do some accurate dimension measurements of these 230Ah calls you received please? Both the basic cell, and the overall size including posts would help a lot.

Someone is going to be here over the weekend who will be able to take the Storm 4 apart and see whether we could cram 8 inside it safely.

[Burgerman]

Its going to work for width with free space, length about exactly the same, and height will be the thing that MAY screw you up. Its extremely tight in that chair.
But I managed to get a bunch of extra cables on top of the MKs in mine for external Andesons.

Will measure EXACTLY in a bit.

[Burgerman]

With digital micrometer.

53.77 thick at edge, cant measure centre... Looks super flat.
73.88 wide and flat.
204.62 to flat top face
16.22 termital heght from to face of cell.

220.84 total tall with thread terminal height

I ordered some 0.5mm plastic card as base and seperator and for external edges and a couple of rolls of duct tape to fold it together as one.

So in my case add 0.5mm to height. Or 1mm.
Plus I will use plastic push on nut cap/covers to make the top electrically safe.

Meaning the pack ends up inc my extra card, 6mm shorter lengthways.
Width ways, its 29mm narrower.
Height ways its 221, An MK is 210 plus bolts - around 7 to 8mm extra with ring terminal and bolt . So 217. Its approx 3mm taller.


(If 3mm actually matters, fit nuts, then cut 4mm excess thread off with Dremmel cutter disk? And then same as MK)
I dont think it will be a big issue. On that chair I added a big bunch of extra 10mm2 cables. A squash but it fitted...

So these will fit with extra room in plan form in bothe directions. Bit will be 3mm to 4mm taller overall inc 1mm thick base plastic insulation.

[Burgerman]

Just put a GRP24 haze battery (also 210mm to terminal top thread like MK) on my bench. Add ring terminal from loom. .8mm. Add flat washer .8mm. Add spring washer they all use... 1.2mm so now we are up to 210mm + 0.8, 0.8, 1.2, and the 5.5mm bolt head. So 218.3 overall height. Compared to 221/222mm litium.

So 3mm height difference. An 1/8th of an inch.
All other measureents are smaller.

If that really does get in your way... Shorten thread a tiny bit.
Screw on nut then cut.

[foghornleghorn]

Thank you very much

It has been the height concerning me as there appears to be a metal bracing piece across the top. Need all the plastics off and the current batteries out to properly measure though.

[Burgerman]

Wel if all else fails a 6mm trim makes it the same height as you already have...

And I got all these extra wires in there!

[Burgerman]

Will it fit in a Dietz chair?

https://www.wheelchairdriver.com/board/ ... 08#p206606