PINNED - Lithium battery conversion/info

[Burgerman]

Ami at Docan says no problem, and they have stock.

[Burgerman]

Latest quote, will be ordering via paypal today.

Hello John

Thanks for your fast reply, please check the quote:
Grade A EVE 230Ah LiFePO4 cell with laser welded M6 studs Unit Price: US$55/each*8pcs=US$440
DDP sea shipping cost: US$180
Subtotal: US$620

Payment Options:Goods and service fees (PayPal/CC/Visa, etc.) is 5%, Alternatively, bank transfer with a bank fee of approximately $48-$100 per payment
Details:
*Free Gifts:One copper bus bar and two nuts per battery & epoxy boards between battery cells
*DDP International Sea Shipping: All-inclusive fees. No VAT, duty, or taxes.
Reliable 50-70 days delivery via DDP sea shipping. Local delivery to your door with truck, DPD, FedEx, or UPS.

Warm Regards
Amy Zheng
Docan Tech
http://www.docanpower.com

[Burgerman]

https://www.wheelchairdriver.com/board/ ... =2&t=12484

Ordered today.
230Ah of A GRADE EVE cells, for £475, thats much cheaper even than a set of decent Gel batteries like MK. And 5x the range, 20x the lifespan. Thats quite mad.

These 230Ah cells, and this is amy showing them, in 2022:
https://www.youtube.com/watch?v=-jXogB3736A&t=21s

This is Amy testing one and showing details:
https://www.youtube.com/watch?v=PlLr-XzYpyA&t=29s

I think that I trust Docan as they are one of the largest and oldest sellers of these lifepo4 cells. And they are happy to give the lowest prices, garanteed A grade brand new stock, complete with traceable and manufacturer genuine bar code stickers and even have a way for you to test and check these on the site. They also supply the manufacturers test data to match each individual cell/barcode if you ask for it. I will do. But garanteed to be 237Ah or greater and very low impedance. She says she welcomes any testing and wishes me to post the results on their social media sites. And with PayPal how can you go wrong?
Especially at 475 delivered! They have stores and staffed distribution and stock in China, South Africa, EU and the USA.

Includes nuts, fibre seperator plates, and plated link plates. And they package these very very well! Take a look on the website. They do appear to be the real deal. We will see!

Ordered. But unfortunately, 30 to 60 days by sea/then on land so I am now waiting!!!

[Burgerman]

Thank you John

Payment received well, we will ship out soon and keep you informed

Warm Regards
Amy Zheng
Docan Tech
http://www.docanpower.com

++++++++++++++++++++++++++++++++++++++++


Now in anticipation I ordered 6mm ring terminals, not shown and some insulating paper, and some duct tape and a 150A midi fuse.
I already have andersons, cable, a spare charge cable and connector etc.

https://www.amazon.co.uk/dp/B0CRHPJJX3 3.5 inches wide x 30ft
https://www.amazon.co.uk/dp/B0CDLWLYDD 8 inches wide x 30ft
INSULATING PAPER... Self adhesive. For bottom and sides, and between every cell.

Duct Tape (Duck Brand)
https://www.amazon.co.uk/gp/product/B009ZGYUVK

And a 150A MIDI fuse
https://www.amazon.co.uk/gp/product/B00904IRNE

Comp link. https://www.wheelchairdriver.com/board/ ... =2&t=12484

[Burgerman]

Shipping latr today... Amy is on the ball.

Hi John

Pls send me your phone number, shipping agent need it to arrange the shipping lable

[ex-Gooserider]

I am not sure it matters much, as long as they are not wildly different. Like feet.

Thanks... I am almost done with the harness, just need to start connecting it to the packs... I also have to make a mount for the charging connector. It came out sort of ugly, but I think it will work out...

I have a cable for going between the PL8 and the chair, w/ one of the DB-25 size connectors we were using a long time back... I will be mounting a mating connector on the chair. However I'm having to do the battery as two packs, each 6S4P... So I have also put a pair of JST-HM series 5 pin connectors in to do the balance wires, and a pair of Anderson 30A PowerPole connectors for the charge power cables... That way I can build up each pack completely and then plug it into the chair connector when I install them.... I'll try to do some photos later...

A couple of other questions...

I've seen that battery monitor you plug into the main harness - do you leave that in permanently or just for testing? If it's in permanently where do you mount it? Is it reasonably weatherproof (some of the ones I've looked at have ventilation slots in the back?) I'm a bit concerned about it given that it sees full chair power so those wires need to be well protected...

Otherwise what do you use for monitoring?

I think I've asked before, but if I do find myself running low on power, is it reasonably safe to plug in some sort of power supply w/o worrying about balancing etc. to give a quick partial charge? Or what about some cheapo balancing charger? It doesn't seem practical to try and set up a PL8 and power supply everywhere but I have plenty of 24VDC supplies, or could do a DC-DC in my van pretty easily....

ex-Gooserider

[Burgerman]

I only use that hobby turnigy thing for testing. So can count Ah out.

I dont monitor anything much. One you know how much 10 miles takes, in Ah the rest can be in your head. So no need to measure anything.

If the pack is big enough, read the miles off the joystick, (or your phone) or just judge it by feel. And then charge later and look what went back in. After a week you already know how many miles (or how much your ass and spine hurt) at say half a pack. And then mentally do the maths if you go further.

If you take note you will also see what miles, when a light on the joystick goes out and again what went back via the charger. So you can see if the big mountain you went up halved your mile per Ah. After a while you will see that range is just huge and quit worrying about it. You do this checking the battery state now as you are used to having to check it with lead (range anxiety) all the time. With a decent lithium pack that need just goes away. After a week or two you dont ever think about looking. Battery meter not really needed.

I am not using the 230Ah packs yet. Only 120Ah. And even that is hard to use in a day. And I tried! But you can do it. Well 2/3rds of it just by watching a light go out. Or clocking the miles. If you try to. Your spine tells you to stop before the battery is too low. And a light will go out when things start to drop a little.
Hence the 230Ah pack should double even this huge range. In winter when keeping warm is more important than rolling across the whole county I think this may last a week befor seeing a light go out. After a few days I will plug in the $3 cell volt monitor and check maybe.

Shirley uses a simple volt meter, and has made a note of volts (and miles?) v what goes back in when charging. You can plug that into the XLR after you lose a light or if just interested. Again you soon figure out at what point you are around 2/3rds battery used. From volts, light out, miles on joystick etc. After that you can go about half as far as you already have. If you must. If it gets to that stage where I worry about going too low, I have a 3 dollar tiny cell volt monitor from eBay... That has a similar connector on it to the one you use for a charge lead. Ending in a normal 8S balance connector. And about 2 feet of thin 8s balance wire. I can plug that into the charge/balance port when the battery gets low just to check each cell, actual cell voltage etc. And try not to go below 3.0 VPC. You wont hurt it even if one reaches 2.5V. But best not to.

With a 230Ah pack all this is even less important and becomes a bit silly. As that is just not really ever going to run short of juice in a days ride. I doubt you could use half of it unless you purposely aim to do so. Or climb a mountain.

[Burgerman]

I think I've asked before, but if I do find myself running low on power, is it reasonably safe to plug in some sort of power supply w/o worrying about balancing etc. to give a quick partial charge?

Yes. No single cell will shoot up high unless you get to around 95% FULL. Or more. But you cannot do this by monitoring voltage. That wont tell you anything until after a cell suddenly hits the stars. Just be sure you put back say 30Ah when you know that it will take 50Ah to fill it.

Or what about some cheapo balancing charger? It doesn't seem practical to try and set up a PL8 and power supply everywhere but I have plenty of 24VDC supplies, or could do a DC-DC in my van pretty easily....

A PL8 is small and light. It will run from any of your power supplies dotted about.
If this pack is big enough you are not going to need them.
If you do put some back with a simple power supply it will need some form of current imiting. And I suggest a 3.400V per cell limit. That will NOT stop a cell exceeding 3.65V when full though if the rest are not. But it will help a little. It will slow down charge though.

If you have huge range you likely wont need to do this which is why we do lithium to begin with.

[Burgerman]

Here are the test results from EVE who make the cells. Sheet supplied by Amy.
And these can be specifically checked against my 8 cells once I recieve them.
Seems that the 230Ah cells are really 245Ah.

Hi John

Yes, attached is the EVE 230Ah grade A cell Specification for your reference;
For your cells test report, once you received you can send me the QR code to check for you.

Warm Regards
Amy Zheng
Docan Tech
http://www.docanpower.com

Shows first 30 cell test results from this batch of 2000. All 2000 are very similar according to Amy.

Note all are significantly greater than 230Ah, typically 245Ah in fact. And all super low impdance - below 2mOhm and closely matched. This is what you should expect from EV grade or A grade new cells. I can check all this on delivery. I have impedance meter (1khz AC 4 wire mOhm meter) and PL8 for capacity measurement. She says I should post results on their social media.

Also included a 3MB pdf file. Too big to post here. With loads of specs and info.

When my specific cells arrive I will send the QR code to her, and get the specific data, resistance, capacity, etc for my own cells. They may be on the green sheet above. But they buy 2000 cells at a time (many sheets!) so maybe not. All specs are very similar though.

I think at these keep prices its not worth buying elsewhere! This company is the real deal as far as I an tell, great communication, good history, good feedback, great prices, slow sea shipping... Cant win them all!

[shirley_hkg]

I think I've asked before, but if I do find myself running low on power, is it reasonably safe to plug in some sort of power supply w/o worrying about balancing etc. to give a quick partial charge?

Right. You're not charging it full. It starts climbing up fast after 27.4V, so avoid getting beyond that.

A £1 voltmetre is far useful than you'd imagine.

You'd forget how far you've wheeled in one charge, wouldn't you ?

Or what about some cheapo balancing charger? It doesn't seem practical to try and set up a PL8 and power supply everywhere but I have plenty of 24VDC supplies, or could do a DC-DC in my van pretty easily....

You've all the connections ready for a hobby charger, if you were charging it with PL8 at home.

I made a tiny BMS that plugs into the charge connector , and use any dump charger when going for holidays .

[Burgerman]

Yu see that last picture showing the adjustment pot?
VERY important. These things are all calibrated by an orangutang on acid.

Most are at least 1/10th of a volt out, some more. A lot more!
But at least it is easy to set correctly if you have a half decent multimeter. Or the PL8 is good and accurate on monitor.

So set it to read correctly around the 28V region.

I actually had one of this, with an XLR fitted in the bag on the back of my chair. But I never used it.
So I have one of these instead.
https://www.ebay.com/itm/403825063039
With a thin 8s balance cable, and a DSUB 25 on the other end to plug into the charger connection. It rolls up so small it takes up little space in a wallet... Set the alarm to warn you and only use it if you feel the battery may be pushed too low. Dont leave permananty connected. It runs from the first cell or 2 cells. So gradually unbalances the battery. In about a week if you forget to disconnect it. This doesent matter as the PL8 rebalances it regardless. But its really for intermittent checks. You get 5 for 13 dollars... Set your own alarm voltage.

and better more advanced ones but bigger are available....
https://www.progressiverc.com/products/cellmeter-8

2 foot long 8s balance cable costs more! Chop of end. Slide a thin sleeve over the flat cable, add your Sub d to the end. ROLL it up and stick it in a bag or pocket. I have a string pull pouch for it. Ebay. https://www.ebay.com/itm/333892255181

[Burgerman]

As you can see. Theres a bunch of ways. But the real answer is fit enough Ah and just igNore it. If you have a pack that does way more than you can, then theres a huge bunch of advantages for the battery. And you (no range anxiety) and no limits.. And no need to think about its discharge level in normal use at all.

The only times I really care is if going a few days and I lose track of miles, or whatever. Then if I lose a light on the joystick I head back home.

The meters are only needed for extreme testing to empty. So no single cell gets lower than it should right at the very end. The last 1% distance.

With r-net you can adjust the battery guage to start losing lights at some point where the voltage reaches some known level in "battery calibration" and battery cable milliohms. If you were to bother. But that depends on some unknown lead based algorythm so not really going to be accurate. But its a guide. Dont run until lights start dropping off fast! If you do then you run the risk of ONE cell dropping the most right at the end. THAT is where the little cell los become useful. But I never go there.

[Burgerman]

SPECIFIC TO EVE 230Ah Cells:
-EVE Power CO., Ltd. Confidential Proprietary-
Model LF230 PBRI-LF230-D06
Product Model LF230

Nominal Voltage 3.2V 0.5C discharge, 25℃ ±2℃, 2.5 V ~ 3.65 V
Discharging Cut-off Voltage (Umin) 2.5 V above 0 centigrade.
Maximum Instantaneous Discharging Current 3C 60 seconds at greater than 30% charge, at 25℃ ±2℃ (thats a max of 690A)
Maximum Instantaneous Charging Current 2C 60 seconds below 80% state of charge at 25℃ ±2℃ (thats 460A)

Charging Cut-off Voltage(Umax) 3.65 Volts.
Weight 4140 g ±124 g (4.14kg)
Initial Internal resistance 0.20 mΩ ± 0.05 mΩ AC 1 kHz 30% ~ 40% SOC (actual tests showed just under 2mOhm for all 2000 cells batch tested)
Min. Capacity 230.0Ah 0.5 C / 0.5 C 25℃ ±2℃ down to 2.5 V ~ from 3.65V charge. (actual test results found 245Ah average, lowest outlier 2000 cells tested, 237.5Ah)

[Burgerman]

exgoose if you really want to monitor the cells, just push the boat out and get one of these. A bit more than you need but graphically good too.
https://www.amazon.co.uk/ISDT-BattGo-Ba ... B07WZFS7D8


youtu.be/pPL9GLAmGRI

It can do a bunch of ther stuff you wont need. And when not using the chair dont leave in connected. But you cant if you got to unplug it to charge the chair anyway. Why? It runs from cells 1 and 2. So would eventually discharge these a bit over a week? But charging will rebalance anyway.

I have one. Only connect it when first using a chair to learn how many R-Net miles/lights out you get when. Then I dont bother. Unless I go a long way and worry about a cell going too low. Its tiny, the connector plug is bigger. So it hangs on my chair in a string draw black bag in case I want it.

[Burgerman]

Now he is a bit of a dummy. But it shows that it can grahically monitor and balance cells. Albeit slowly...

This shows that you can calibrate it yourself too.
https://www.youtube.com/watch?v=SmrLiDP4A2k

I already have one. From 2017. Works well. Was already good enough. If you DO decide to calibrate it, then you need a multimeter than can display 1mV and do so accurately. And repeatable. I would use my calibrated fluke 289 but any half decent meter should be able to do 3 decimal places at 3.6V aprox?

My cheap fluke cant... But my good one can.

[fishinjunky]

[quote="Burgerman"]exgoose if you really want to monitor the cells, just push the boat out and get one of these. A bit more than you need but graphically good too.
https://www.amazon.co.uk/ISDT-BattGo-Ba ... B07WZFS7D8

I have this same one but have not used it yet. I think it can be used to monitor cells by just plugging in balance cables an not the XT60I plug but wont get as much information. Ill have to try mine out this week

[shirley_hkg]

I've never use these cell checkers anymore, since installed big enough pack.

I did have a glimpse of the cell voltages to see if they were consistent , every time I recharged.

By comparing the Ah returned, I shall know too the reserve that left.

[Burgerman]

Sae here. Big enough. No need to bother. But I think its an old small heaway pack, he is refering to. So not sure of capacity.

[Burgerman]

I have this same one but have not used it yet. I think it can be used to monitor cells by just plugging in balance cables an not the XT60I plug but wont get as much information. Ill have to try mine out this week

From memory you only need the 9 pin connector.
The main power connector isnt needed unless you are using the pack to power it, and the balance port wires to test 1 cell. As it wont run on under 5V. Or if you are testing lead, nickel metal, a BMS equipped pack, or using it to power a USB charger.

If you just want a graphical battery meter, and an alarm, at x level of lowest cell, then you need only the 9 pin.

Its also a balancer. Albeit super slow! Even on a hobby sized battery. But if you worry about the charge, this will tell you all you need to know!

A quick check with my fluke just now tells me I need to calibrate it. Its about 7mV spread. Fortunately thats very easy. They dont much seem to bother. Its close enough as a fuel gauge though. But if you choose balance, it would spend all day unbalancing! At least on our packs. But its so weedy as a balancer I doubt you could tell...

[Burgerman]

Also. After doing a little research and talking to some EV car builders a year ago...

When you buy any prismatic cells, they should show zero oxydation. All the posts should look like fresh metal. The sides should be as flat as a sheet of glass. And the codes on the top should be tracable online to the manufacturer with complete specs for that cell inc sate of manufacture, measered performance etc. IF these were new, A Grade factory fresh cells. ANY minute bulge or non flat sides, corner to corner show that they are used. And made to look new again.

And EVE cells have heavier thicker walls so better than most other brands even catl etc. As we dont clamp them and so they are less inclined to expand and shrink with use or charging.

And as of now the prices are still dropping as sales of single cells as we use them are dropping in favour of server style racks - mostly used in solar systems.

So avoid the masses of junk sold on AliExpress etc, Alibaba, and the like. Almost all of those are not what they claim to be. With the odd exception like docan who also sell there. But the prices or real A grade cells, that exceed the rated capacity, that are totalky flat, are now pretty much the same anyway.

[ex-Gooserider]

Thanks for the responses about monitoring and charging, they were very helpful, though some might not work well for me...

My pack is made of the old 15Ah Headway cylindrical cells - 6p8s for a nominal 90Ah, but I had charged them up when I first got them and then life interfered and they've sat for a few years at full charge. All still show the same voltage within about +/- 10mV, IIRC ~3.215V or so. However BM and Shirley both say that this will probably cost me some capacity so I'm expecting about the same or just a bit better as I was getting w/ my Sears (Odyssey rebrands) lead bricks when they were new....

I will have trouble getting a distance estimate as my chair is still running on Pilot+ electronics, w/ the basic joystick that has 'charge' lights and not much more... (R-net may be better but BM used to love Pilot+) However I don't do huge distances, as I have a van for that, but do a lot of short distances and tight moving around, mostly indoors. Is there any adjustment on the Pilot + for the voltage when the lights start dropping?

ex-Gooserider

[Burgerman]

I dont remember!

But you will lose a light at about 2/3rds done. Depending of how it has been configured.

Do this.
Fully charge and balance at 3.65V. If its been sat it might take a long time.
Then do a discharge test to 2.7V per cell at max amps. It will drop to whatever is 100 watts...
Note capacity and see which cell drops lowest first to check if any are damaged.

Then recharge to normal 3.600V or 3.550.

Drive around until you lose a light. Charge. See what goes back in. Then you will know how many Ah you used at the first light. You can do the same with 2 lights out but I might use a cell log to be sure you dont go lower than 2.5V on any cell.

Then charge again. Remember the two figures. Then you will know all you need. Even without a milometer or GPS or Ah meter etc.

[ex-Gooserider]

OK, it looks like the fancy battery tester really doesn't do anything for me that the voltmeters and cell checkers I already have will do... Doesn't sound like it's worth the effort to add the ability to plug in one of those battery amp meters either... I will need to finish building up the pack wiring etc. before I can start the testing you suggest, but that is my next step...

FWIW, here are some shots of what I've done so far - both packs are identically built, but once I start wiring, one will be cell strings 1-4 and the other 5-8. The balance wire that goes between cells 4 and 5 is connecting to the appropriate point on each pack, which is probably redundant considering that there will also be an AWG 8 cable connecting the two packs, but...

Top of the packs -

top of packs

Bottom of the packs -

bottom of packs

Charge harness - not yet terminated on pack end -

Charge harness - not yet terminated on pack end

[steves1977uk]

ex-G, there's a setting in the manufacturing version of the mobility programming software for the Pilot+. I think it's battery gauge calibration or something similar, I've had it set to 130% and the battery gauge drops faster. I've never really experimented with finding the best value. Try it and see how it goes.

Steve

[ex-Gooserider]

ex-G, there's a setting in the manufacturing version of the mobility programming software for the Pilot+. I think it's battery gauge calibration or something similar, I've had it set to 130% and the battery gauge drops faster. I've never really experimented with finding the best value. Try it and see how it goes.

Steve

Thanks Steve! Will take a look for that setting.

Getting back to the pack, I've now gotten the two packs wired up... I've encountered a bit of a problem w/ getting to use my PL-8 on them though.... I don't have a functioning Windows box at this time, which wouldn't be a problem except that the PL-8 software won't run on a real GNU/Linux box

Has anyone gotten it to run under WINE? I've been trying but not having a lot of luck, but I'm not sure if it is a problem with the software, or my lack of experience w/ making a functioning WINE setup...

I'm also not sure I have all the software for the PL-8, I have the setup.exe that I know used to go to a website and download / install everything, but does that still work now that Revolectrix is gone?

At any rate, a few more photos....

The bottom of the strings 1-4 pack

The bottom of the strings 1-4 pack

The top of the strings 1-4 pack

The top of the strings 1-4 pack

The top of the strings 5-8 pack

The attachment pack1-4-bottom.jpg is no longer available

The big blob on the end of the cable that goes between the pack is a MIDI fuse holder that I stole from an Invacare battery box lid, with a 120A fuse in it.... I know those cables are far longer than needed, but they were ready made cables that came off some other chair and it was easier to reuse them than to re-make them...

ex-Gooserider

[Burgerman]

Get a PROPER windows computer. Not that old half finished nonsense.

heres the software. Includes latest firmware, driver etc.

http://www.wheelchairdriver.com/doomed/PL8/

[ex-Gooserider]

Another item I've been working on because of the discussion about battery checkers is making a mini-tester for occasional status checking.... I have a bunch of cheapo cell testers that I purchased years ago that should do the job just fine...

I started with another one of the charger plugs and modified it by cutting off the solder cups for the large pins:

new and modified connectors

I used one of our vertical band saws, and the biggest problem was figuring out work-holding... I clamped one ear in a small vice which let me do the cutting w/o getting my fingers to close to the blade... I did get a little nick in one of the small cups....

I then took one of the cell testers and removed pins 6-9, and bent the remaining pins 1-5 to match the spacing of the solder cups on the modified connector. I soldered them into the connector, and then put in jumper wires (I think AWG 24, but not sure since they don't carry any real current, it doesn't matter...) to connect the connector pins 6-9 to the tester in place of the pins I removed earlier...

The result:

Bottom

Top

I still need to test and verify that it works right, but after that I'll mount it in a modified shell and possibly embed it in some clear resin....

ex-Gooserider

[ex-Gooserider]

Get a PROPER windows computer. Not that old half finished nonsense.

heres the software. Includes latest firmware, driver etc.

http://www.wheelchairdriver.com/doomed/PL8/

I have an older Dell Laptop, (latitude E6400, Intel 3.06Ghz Core Duo CPU, 8GB RAM) and a 120GB SSD that I can put in it, aside from a dead battery it works OK, and is the best/fastest in my collection of spares...

I don't have a good copy of Windows to put on it... I have an old copy of W10LTSC_64 that I got a few years back, but I haven't been able to get it to install on the drive - any chance of getting a new copy w/ the installer? I've been trying to copy the ISO to a USB stick and keep getting messages that the stick isn't bootable...

ex-Gooserider

[Burgerman]

Does it boot into anything you have that is windows based from a usb or anything?

I am trying to acertain what to send you...


If you have any old version of windows that is installable from a USB stick then I can send you a zip or rar file with all the stuff you need that you can just run from the desktop. Or from a strelec boot disk, or a restore disk for a backup program such as ghost or macrium or whatever?

How will you install it?

[ex-Gooserider]

Does it boot into anything you have that is windows based from a usb or anything?

I am trying to acertain what to send you...


If you have any old version of windows that is installable from a USB stick then I can send you a zip or rar file with all the stuff you need that you can just run from the desktop. Or from a strelec boot disk, or a restore disk for a backup program such as ghost or macrium or whatever?

How will you install it?

I don't have anything that boots Windows that I know of... The laptop has a DVD drive and USB ports, so I can boot off either... My desktop is GNU/Linux and I can burn DVD's or write USB sticks, that the laptop should be able to boot from. The SSD is currently ext4 formatted, and has a Debian install on it, but I have no problem reformatting it. I could mount the SSD on my desktop and use some of my Linux programs to reformat it to ntfs or FAT12, 16, or 32 (I believe one of those is what windows uses? - MS-DOS or GPT?) but don't think I can make it bootable as I don't have the windows setup files...

ex-Gooserider