Group 24 cells

[Burgerman]

https://www.wheelchairdriver.com/board/viewtopic.php?f=2&t=12134

You may not get 209 height.

Last month, I put 160Ah in a Quickie QM-710 , which is in lack of space similarly.

However, one 350mm side is needed still.

https://www.youtube.com/watch?v=xxPy7NUDvLY

Which measurement was bad for the q710m?
Because looking a the above the 230Ah ones would have fitted. Total height 13mm taller. But that one has at least 13mm clerance because of the ussquashed red and back pvc caps?

[Burgerman]

OK. More info...
We can order these with a laser welded thread M6, and total height is 212mm,

Add 6mm for a dome head allen screw and 2mm for the terminal tab thickness and its then around 220 including the bolt/terminal etc. Not much different to MK because 208 plus same 6+2 bolt etc means 216 total. Only 4mm taller total. So now these may fit?

P.S. Best read most of the preious page in case you missed it!

[shirley_hkg]

M6 stud is 15mm tall, but it is not needed for a ring terminal, washer and a lock nut.

It will be shorter than a welded nut , if you could trim the excessive stud. .

Which measurement was bad for the q710m?
Because looking a the above the 230Ah ones would have fitted. Total height 13mm taller. But that one has at least 13mm clerance because of the ussquashed red and back pvc caps?

That's the 353mm compartment length.

It's gone now with the zigzag arrangement .

[Burgerman]

Oh. Thought you meant height! Yes it cures the length issue. I didnt realise that was an issue. I am keeping my really bad drawing drawing as it might help others that thought it wouldnt fit. Been saying these fit for years but I never realised that nobody had understood quite how I meant. A (bad) drawing is worth a 1000 words.

Tell me how much can be trimmed from the thread? As this will lower the height. Seems very long. Never had one of those here to measure. Can trim them with a small angle grinder. Screw on a nut, then add a ring spanner as heat sink. Then trim off the rest... How much shorter can they be made?

Cells are actually 173 and 53mm = not 175/55.
So I changed the actual final measurement at the bottom.
Now 332mm long.

[jefferso]

The 160Ah page has some conflicting size information

https://www.docanpower.com/index.php?ro ... ption=true
(also a typo says 106Ah in the title)

The text says 174 x 154 x 54 but one of the photos shows 173.9 x 204.6 x 41. I think the text is correct because it matches the specs and diagram in the PDF Amy sent.

I tried to draw to scale and leave at least 1mm between and it looks like it will fit if 2 MK Gels will fit. The 230Ah and 160Ah have the same length and width, so it's only the height issue between them and I just don't know if it will fit in the Permobil space.

One thing that concerns me is my chair is a bit top heavy because it's a standing chair. With the 160Ah there should be room for some lead, tungsten or tungsten carbide plates underneath to add some extra weight down low for centre of gravity.

[Burgerman]

I am going to steal your drawing. Its better than my somewhat drunken rushed one!

Height...
I am going to cut the threaded stud length down. We only need enough length for a ring terminal, a small ring terminal (balance) and a nyloc nut. Thats 7mm of thread. So I will add some washers, a nut, and using my 12V angle grinder chop off the extra 10mm or so. On all 16 threads.

So that will reduce it down from 227 to what? I dont know yet! Ws rying to get a measurement from shirley who has these cells already. I think. I dont have one here to measure. I DID have a set a few months ago but just used them as is in someones scooter. They were also not from Dorcan. But I have spoken to dorken in the past years back and they seem reliable, cheap, and what it says on the tin. Hopefully! Its as legit as any that we can find. 30 TO 60 DAYS DELIVERY THOUGH

[LROBBINS]

Height was also an issue in Rachi's chair and when I switched to 205 AHr LiFePO4 many months ago I did what Shirley has suggested. Attached the ring terminals with their 10mm^2 wires and the balance leads with thin ring terminals with a plain 6mm nut & used a dremel type grinder with cut off disc to trim the screws flush with the top of the nut. The heavy wires and ring terminals are quite sufficient as heat sinking for this. Removed the nuts, added loctite and screwed them back on.

[Burgerman]

Thats similar to what I will do. I dont think its needed on the salsa but it has a metal bar going across the chair where the batteries are loaded and it will be super close. And its all live so if it touches there will be a lot of smoke etc...

How are you getting on with 200Ah?
I would imagine that you would get around 80 miles of range. Or 4x as much as lead. Have you done any Ah per mile measurements?

Actually where you live, and at low speeds on foot maybe not as much. But its interesting to know?


Same EVE cells 230Ah even cheaper here. 8 delivered £555 pounds...

If this keeps up they will be paying us soon. In this country that is CHEAPER than buying 2 MKs. And instead of 1 years lifespan, you get 15 or so. And you get a 230Ah usable instead of 45 to 50Ah befor it stops. So a 5x bigger fuel tank too. How can anyone use lead bricks today?

[jefferso]

It looks like there's not much room at all in the middle of where the batteries go, but they've allowed a little on either side for where the cables attach to the Terminals.

Video: How to Install 75 AMP Gel Recessed Post Batteries into a Permobil F5 Power Chair - Marc's Mobility
https://youtu.be/oco3JqG0lVw?t=250

I added width dimension of the cell arrangement to the diagram. There should be 1 or 2mm between each cell so the total space needed is 230mm x 340mm.

[Burgerman]

Looks like a pig of a thing to work on.
Yes battery height will be an issue in your case.

While watchng that vid I couldnt help but notice (apart from a crap load of extra permobil odules/wiring/plugs etc) that the whole seating platform was bolted on with 2 large bolts that you can see in the video.

Presuming that the opposite end is the same, what stops you unbolting this, swapping the full seating 180 degrees. And turning it into a rear drive chair? That would allow you to toss the permobil gyro in the bin, program the chair in the normal rear drive way using the correct part of the R-Net menu and have a rear drive chair in the US. Looks very simple from this end! Cant see the other end though.

[jefferso]

Presuming that the opposite end is the same, what stops you unbolting this, swapping the full seating 180 degrees. And turning it into a rear drive chair? That would allow you to toss the permobil gyro in the bin, program the chair in the normal rear drive way using the correct part of the R-Net menu and have a rear drive chair in the US. Looks very simple from this end! Cant see the other end though.

Permobil!

I imagine there are a bunch of interconnected sensors. Like the front anti-tip wheels have to touch the ground when standing, and then there would need to be room for the foot plates on the other end. Plus, such an experiment is way beyond my capabilities. It would be fun though, and very confusing for the Permobil rep if I had to call them for something.

I'm pretty used to FWD after a decade and a half or so though. This chair does get an annoying castor wheel flutter if I go over a bump at speed sometimes.

[Burgerman]

Binning all the permobil electronics, turning it into a decent rear drive and fitting lithium would be the very thing I would do. Make it into a decent chair and confuse the crap out of the permobil techs.

[LROBBINS]

How are you getting on with 200Ah?
I would imagine that you would get around 80 miles of range. Or 4x as much as lead. Have you done any Ah per mile measurements?

Actually where you live, and at low speeds on foot maybe not as much. But its interesting to know?

I have no idea about miles. What I do know is that Rachi uses about 90 AHr in two weeks of winter activity. It will go up when summer arrives. Remember too that she has a tablet PC active whenever the chair is on, and in "modern standby" which is nearly as greedy when the chair is off - about 2-3 AHr every 24 hours, so as much as half of those 90 AHr in two weeks.

[Burgerman]

When you say rachi uses 90Ah in winter activity is this all indoors and does she move around indoors much?

I use as much energy indoors as I do going into town to the bank etc. It seems that if you are inside turning left/right and shuffling about but going pretty much nowhere you can use 40 or more Ah indoors a day quite easily! Obviously rachi is much lighter and likely isnt tearing around cleaning and fixing things like I do. If she can still move around at all.

Worse when using a leaf blower for 30 mins I make the chair roll back power due to heat and it wont let me move! Because its programmed to respond and I am darting about turning to face different directions every few seconds. But I can kill a lead battery down to red lights in 2 hours just clearing leaves or pressure washing driveway.

Distance is the easy part! Straight lines and constant rolling means low current.

How far do you go in summer? I mean you are on foot. So it cant be that far. I doubt that your battery drain will increase very much compared to indoors. Unless she is pretty static inside. Can and does rachi still drive herself around or do you or your wife do all of that for her?

[LROBBINS]

Rachi can no longer drive the chair herself, so it is Ellen, myself or her aide Genny using the attendant joystick. In the winter she is mostly indoors on ceramic tile surfaces and a few hours a day out of the chair stretched out on her water bed. In the summer she and Genny will be traveling everywhere nearly every day. Much of that is in the car, but wherever they get to (and it can be Siena to Venezia and back in 1 day) they go everywhere on all sorts of terrain. Lots of hills hereabouts and very rough sidewalks or even semi-mountain trails. The most frequent single destination is the seaside where they are often plowing through sand. My guess, and it's only that really, is that she'll be drawing 90 AHr a week rather than every two weeks. Wherever she is, the lift and tilt are moved many times a day - and they are much faster than what's usually on a chair so do draw more current - but 5 to 10 Amps tops moving her 40 kg. These cells are going to last forever. I recently added a total battery current sensor to the CANbus system, so over the next few months I'll get a better idea of how much is used in different situations.

[Burgerman]

Well unless she or whowever is driving the chair is accelerating at max power at speed then I doubt you will see more than 15 or 20A at the battery. At low speeds on foot, even hills or and will not likely go higher. So they should last well!

[jefferso]

Height was also an issue in Rachi's chair and when I switched to 205 AHr LiFePO4 many months ago I did what Shirley has suggested.

Do you know the dimensions of the 205Ah cells you got? Are they the same as the 230Ah cells? 174mm x 54mm x 204mm ?

[jefferso]

The 160Ah page has some conflicting size information

https://www.docanpower.com/index.php?ro ... ption=true
(also a typo says 106Ah in the title)

The text says 174 x 154 x 54 but one of the photos shows 173.9 x 204.6 x 41. I think the text is correct because it matches the specs and diagram in the PDF Amy sent.

I wrote Amy at Docan Power about the typo and inconsistency in sizes on the web page and they fixed it right away.
She's quite responsive.

[Burgerman]

Yes they seem very keen. Even 5 or 6 years on.

I have been looking for cells that are slightly less tall. Aliexpress. But the only ones I find are either the same or 201mm. So only gain 6mm.

The reason is that I am not 100% sure of the height of the access on the battery slide in/out at the rear of the salsa until I measure it. But it seems like it would work but be tight at 227mm. Dont want any sparks when installing!

[jefferso]

I have been looking for cells that are slightly less tall. Aliexpress. But the only ones I find are either the same or 201mm. So only gain 6mm.

There are still these outliers which claim to be 240Ah and 175* 48 *185mm but with the lower weight of 2.8kg. I don't see reviews for them though.

https://www.aliexpress.com/item/1005006515947627.html
https://www.aliexpress.com/item/1005006651722355.html
https://www.aliexpress.com/item/1005006609307598.html

[shirley_hkg]

Just focus on popular ones only. Awkward configuration means incorrect information or obsolete cells produced long time ago .

[shirley_hkg]

Tell me how much can be trimmed from the thread? As this will lower the height. Seems very long. Never had one of those here to measure. Can trim them with a small angle grinder. Screw on a nut, then add a ring spanner as heat sink. Then trim off the rest... How much shorter can they be made?
.

Here it is. 4.5mm I guess. M6 threads.

[Burgerman]

Excellent thanks.

[LROBBINS]

You can trim a little more if you use a plain nut and loctite instead of the anti vibration nut. Given that it's not really under tensile stress, you can even treat it as a jam nut and trim it thinner than that (say another 1mm).

[Burgerman]

I have a box of 100 thin M6 stainless nuts. And blue and red loctite... So yes! I can likely get 8mm off that height. Also only 1 ring terminal, and crimp/solder the balance wires into the terminal together. And now I have to measure the chair carefully. But now I have to pay for nikons ultimate 135 f1.8 portrait lens too. And you dont want to know how much that was.



youtu.be/6o8Rq1aL1mM

[Burgerman]

Which may delay me for a few weeks...

But I like photography too! This is nikons best ever portrait lens they ever made. I tested one. Now I got to have one... Even a chair leg looks like art with this thing.

[swalker]

Burgerman, the pattern you suggest is what I have considered.

In my case, I want to allow for one or more cells to be a bit bulged (in my last order of 8 cells from China, all were bulged some and 2 where bulged significantly).

I just don't think there is quite enough space for the cells in my Permobil F5 when arranged according to your diagram if one or more cells are bulged and if I put some insulating material between the cells.

I need cells that are not as tall, not as wide, and not as thick. I have considered going to 105, 150, and 160 cells and still have not found a solution I am comfortable with.

Steve

[daveonwheels]

I have a box of 100 thin M6 stainless nuts. And blue and red loctite... So yes! I can likely get 8mm off that height. Also only 1 ring terminal, and crimp/solder the balance wires into the terminal together. And now I have to measure the chair carefully. But now I have to pay for nikons ultimate 135 f1.8 portrait lens too. And you dont want to know how much that was.



youtu.be/6o8Rq1aL1mM

$2,495 USD

[Burgerman]

under 2k if you know how to buy right. But still not cheap.

[Burgerman]

I certainly wouldnt be using any bulged cell. It just means they have been charged or discharged at a level (current) or charged at too high voltage that has damaged the cell. It causes gassing internally that pushes the plates apart. That in turn causes intrnal resistance increase. Which causes more heating under load and rinse and repeat. Can also be caused by cells assembled in a less than dry atmospere. They should really have been refused and disposed of if theres ANY bulging at all.