PINNED - Lithium battery conversion/info

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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 11 Sep 2018, 17:42

Burgerman wrote:Yes charge fully. It may take a while... They wont be balanced at all.


Ok.

Burgerman wrote:The purpose of the charge cable? So you can connect one connector to a socket mounted on the chair, then press charge!


How long is your cable on the side of the PL8?

How long can I make the cable on the battery side? I need it to be long, otherwise I'll have to put the PL8 on the floor.
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Re: PINNED - Lithium battery conversion/info

Postby Burgerman » 11 Sep 2018, 19:29

My cable is a meter. 3 feet actually. But half that would be enough.

But I just plonk the PL8 on my chairs seat, after I transfer to my bed, along sith phone, wallet, and other junk. And plug its USB connector into my "bed" laptop. And the 40A subD connector into the chair. That is a small 12 inch laptop with 13 inch touch screen. The power supply stays under my bed, and has a 6 foot power cable. I drive the charger via the laptop, and then use it to watch a movie or answer questions like this! And the charger software logs the and graphs the charge till morning.
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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 11 Sep 2018, 23:57

Burgerman wrote:My cable is a meter. 3 feet actually. But half that would be enough.


How did you get 3 feet in length if the banana plug cable that Revolectrix sells only measures 1,64 feet? The one sent to me from Revolectrix store is only 1,64 feet...
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Re: PINNED - Lithium battery conversion/info

Postby Burgerman » 12 Sep 2018, 00:23

I bought the safe connectors on ebay, and a 30 meter roll of cable in each colour.

https://www.ebay.co.uk/itm/10Pcs-Red-Bl ... SwkX9Zo8wL

Use ONLY the above, as they are the only ones that are good at 40A without melting, and because you cant short out the battery.

Use only silicone cable, same size as the stock leads from revolectrix.

https://www.ebay.co.uk/itm/Flexible-Sof ... 0506.m3226
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Re: PINNED - Lithium battery conversion/info

Postby cavorite » 12 Sep 2018, 01:26

Has anyone worked out the details on a 22NF replacement pack, 40152 based, 8S4P or 8S5P? This would be on a Pride Quantum Q6. I have to replace my batteries, and MK gels aren’t cheap. I know this will cost more up front, but the increased lifespan balances that out. All the other benefits are icing on the cake.
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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 12 Sep 2018, 02:29

How do you connect the cable to the bananas? Soldering it?

Did you re-use the fuses from the cable sold by Revolectrix for the new cable?

I already charged the battery:

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Is everything okay?
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Re: PINNED - Lithium battery conversion/info

Postby Burgerman » 12 Sep 2018, 02:33

22nf is a difficult size. I looked in the past but nothing seemes a good fit. But over the last 3 years many new cell sizes and suppliers appeared. Mostly on chinese auction sites.

240L 140W 227H is a grp22nf.

So you need either 4 or 8 cells in that shape/space, twice.

For e.g, 16 of these (8 per "battery") would give you a pretty good 140Ah at 24V in that small space. But need 1mm insulation between each cell so measure carefully. When you consider that a typical GRP22NF battery delivers only 25 to 30Ah before the chair stops, and this will give you an easy 120Ah with some left over for safety, then you should be able to get 4.25 times the range...
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Re: PINNED - Lithium battery conversion/info

Postby Burgerman » 12 Sep 2018, 02:52

Other than the power supply dropped a lot! 2 volts.
Check all bolts tight on cell group 2. And that no insulation got between the bus bars. Then:

It looks OK, tell it to discharge, and leave it doing that for say 25Ah out. Will take a long time. Then keep the charge voltage/cells and Amps graph. Then recharge and keep those too.. Also reduce the charge amps by 5A. And set termination current to a lower level, by about 30%.

How do you connect the cable to the bananas? Soldering it?

Did you re-use the fuses from the cable sold by Revolectrix for the new cable?


I have several cables. Some no fuse. Some have a 20mm long bit of 40A fuse wire inside heatshrink, inside the cablesleeve. Yes solder!
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Re: PINNED - Lithium battery conversion/info

Postby snaker » 12 Sep 2018, 03:50

cavorite wrote:Has anyone worked out the details on a 22NF replacement pack, 40152 based, 8S4P or 8S5P? This would be on a Pride Quantum Q6. I have to replace my batteries, and MK gels aren’t cheap. I know this will cost more up front, but the increased lifespan balances that out. All the other benefits are icing on the cake.

My original battery box is 22NF (50Ah). Its size is W=24cm x D=30cm x H=24cm. I modified the tray to extend the width from 24cm to 26cm and ordered a new inox box of size W=26cm x D=30cm x H=24cm. It can fit 16x75Ah cells (or 16x85Ah cells now).
https://photos.app.goo.gl/B68wWkM9FcndCRMA6
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Re: PINNED - Lithium battery conversion/info

Postby cavorite » 12 Sep 2018, 06:38

Snaker, who is the maker of the cells you’re using? I’m not recognizing them.

I like the Headway cells, and they seem to be well thought of. Clearly, I have to do some measuring. At first glance, width is going to be the determining factor. Capacity wise, based on the 22NF SLA having a roughly 50AH capacity (manufacturer’s rating), I was thinking of using the Headway 15 AH cells, 8S for 24 volts, and then 4 or 5 banks in parallel, for 60 or 75 AH.
(BM - can you explain your AH numbers? I’m not following.)

Can I find dimensions for assembled packs (cells in holders) anywhere?
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Re: PINNED - Lithium battery conversion/info

Postby snaker » 12 Sep 2018, 08:30

I bought these cells on Chinese taobao.com, their name is ATL. Now there are better choices from EVE and CATL.
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Re: PINNED - Lithium battery conversion/info

Postby Burgerman » 12 Sep 2018, 10:13

I like the Headway cells, and they seem to be well thought of. Clearly, I have to do some measuring. At first glance, width is going to be the determining factor. Capacity wise,


Headway cells used to be the only way to get a sensible capacity into a box the same size as the grp24 lead brick, and they are quite high C rate meaning they are safe to use in a small capacity without hurting them. Over the last few years there are MANY new different sized cells appeared. And some allow much higher Ah capacity to be used in the space we have available. So its possible to fit more capacity which has many benefits.

based on the 22NF SLA having a roughly 50AH capacity (manufacturer’s rating),

With lead you only usually get around half to twothirds of that out before the voltage drops, and the internal resistance/peukert means you stop... So your 50Ah lead battery is realy a 30Ah one.


I was thinking of using the Headway 15 AH cells, 8S for 24 volts, and then 4 or 5 banks in parallel, for 60 or 75 AH.
(BM - can you explain your AH numbers? I’m not following.)


Those were the first cells I looked at that I found after a quick search. They should allow you to fit 16 cells. They are 72Ah. So they ill allow 8S and 2 in parallel, giving you 144Ah. Way better than your 60Ah with the headway cells. C rate is lower, but since theres 144Ah then thats still better overall! But it will be tight, as those cells need to be wrapped in something to insulate them electrically or spaced apart with 1mm sheets of plastic.

Shirley may tell us they are bad cells, and or offer something better?
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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 12 Sep 2018, 13:53

Burgerman wrote:I bought the safe connectors on ebay, and a 30 meter roll of cable in each colour.

https://www.ebay.co.uk/itm/10Pcs-Red-Bl ... SwkX9Zo8wL

Use ONLY the above, as they are the only ones that are good at 40A without melting, and because you cant short out the battery.

Use only silicone cable, same size as the stock leads from revolectrix.

https://www.ebay.co.uk/itm/Flexible-Sof ... 0506.m3226


Ok, thanks you!

I think I will reuse the banana plug connectors from the original cables I bought from Revolectrix (I bought 4), desolder and solder with a new 12 AWG silicone cable.

As a curiosity, why here silicone cable and not pvc cable if this cable can perhaps be damaged more easily by not being protected inside the shell of the chair?
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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 12 Sep 2018, 13:59

Burgerman wrote:Other than the power supply dropped a lot! 2 volts.


Maybe I should have tightened the PL8 power connector more to the power supply....


Burgerman wrote:Check all bolts tight on cell group 2. And that no insulation got between the bus bars. Then:


Yes, all screws are slightly tightened. I bought a torque wrench to adjust them to the Nm specified by the manufacturer. I think it's 5 Nm, can you confirm that? Do you think that tightened with a torque wrench will save me from using Loctite 242 threadlocker?
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Re: PINNED - Lithium battery conversion/info

Postby cavorite » 12 Sep 2018, 14:37

Those were the first cells I looked at that I found after a quick search. They should allow you to fit 16 cells. They are 72Ah. So they ill allow 8S and 2 in parallel, giving you 144Ah. Way better than your 60Ah with the headway cells.

144AH in a 22NF size would be pretty amazing. Deep discharge would never be a problem. I hope Shirley has a trustable source for these.
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Re: PINNED - Lithium battery conversion/info

Postby Burgerman » 12 Sep 2018, 14:47

Yess 140Ah is much better than the 30 you can get from the 50Ah 22nf batteries. Four and a half times better. So if you got 15 miles before, you will get 67 miles. Or 50 with loads to spare for safety.

I think it's 5 Nm, can you confirm that? Do you think that tightened with a torque wrench will save me from using Loctite 242 threadlocker?


Maybe...
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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 12 Sep 2018, 22:39

What do you think about this extra negative pole protection?

Image

are insulating washers on the negative ends before adding the bus bars to prevent accident contact because the pos+neg voltages are right there a fraction of an inch apart, if both pos+neg come into contact by accident they will create instant spectacular fireworks, right?
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Re: PINNED - Lithium battery conversion/info

Postby Burgerman » 12 Sep 2018, 22:58

As long as they dont get in the way. Throw away those x head screws, use cap head - allen head screws...
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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 12 Sep 2018, 23:51

Burgerman wrote:As long as they dont get in the way. Throw away those x head screws, use cap head - allen head screws...


The battery in that picture is not mine, it's from another forum. I have hexagon head screws Allen round head screw. What I don't know is whether to use split washers that came with the cells...
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Re: PINNED - Lithium battery conversion/info

Postby Burgerman » 13 Sep 2018, 00:11

Best not. Just thin flat washers. Loctite the thread.
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Re: PINNED - Lithium battery conversion/info

Postby shirley_hkg » 13 Sep 2018, 03:22

FJC10 wrote:What do you think about this extra negative pole protection?

are insulating washers on the negative ends before adding the bus bars , right?

It will be problematic , though it is thin.
That will put most of the current to flow through the bolts , which are not a good conductor and more unfortunately , Loctite insulated . :thumbdown:

It's useless. It can't prevent bus bars touching each others anyway , can it ?
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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 13 Sep 2018, 16:30

Burgerman wrote:And set termination current to a lower level, by about 30%.


I'm sorry, but where and how is this set up?

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There? or where?
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Re: PINNED - Lithium battery conversion/info

Postby Burgerman » 13 Sep 2018, 17:15

Manual a setting. Determines the point where the charge ends. Yours ended very fast and easily. So if we lower it it will hold 3.600V for a longer time. Set to 240mA
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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 13 Sep 2018, 19:04

shirley_hkg wrote: It will be problematic , though it is thin.
That will put most of the current to flow through the bolts , which are not a good conductor and more unfortunately , Loctite insulated . :thumbdown:

It's useless. It can't prevent bus bars touching each others anyway , can it ?
czy


He uses a 1 or 1.5 mm thick plastic material

If I didn't misunderstand the guy who invented that extra protection, he puts that in order to avoid contact with some object between the badly isolated positive part of the negative zone of the cell.

I took a picture of one of my badly isolated cell

Image

Image

And in these photos I show an example of a piece of paper. As you can see, it doesn't block the negative pole from making the same contact as without:

Image

Image
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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 13 Sep 2018, 20:19

Burgerman wrote:Best not. Just thin flat washers. Loctite the thread.


I am afraid to use "Loctite Threadlocker 242". If I need to remove it later, I think it may damage the cells because of the extra force needed to loosen them... unfounded fear, I suppose.
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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 13 Sep 2018, 23:47

Burgerman wrote:Manual a setting. Determines the point where the charge ends. Yours ended very fast and easily. So if we lower it it will hold 3.600V for a longer time. Set to 240mA



Image

is OK?

Discharged 25Ah:

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Re: PINNED - Lithium battery conversion/info

Postby Burgerman » 14 Sep 2018, 03:18

Forget fuel graph its meaningless. That only works on LiPos...

Otherwise all looking how it should.

Now charge!
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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 14 Sep 2018, 18:58

Burgerman wrote:Now charge!


Done! 5A, Manual A. Setting 240mA and all bolts tightened to 4 Nm with torque wrench:

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Re: PINNED - Lithium battery conversion/info

Postby Burgerman » 14 Sep 2018, 19:39

Perfect. Only this: https://i.imgur.com/pDdduRL.png
And the pack amps, are the only graphs you need post.
And as I say, fuel is completely meaningless. You can turn fuel off in the fuel tab.

And reduce the charge termination some more. It ends very fast. Sit it to a lower figure for next time. Its 240mA now? Set to 180mA. Then test. Your cells reach full very easily. And you can reduce charge volts to 3.550 or 5.575 too if you wish, as its kinder to the cells long term.
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Re: PINNED - Lithium battery conversion/info

Postby FJC10 » 14 Sep 2018, 20:52

Burgerman wrote:Perfect. Only this: https://i.imgur.com/pDdduRL.png
And the pack amps, are the only graphs you need post.
And as I say, fuel is completely meaningless. You can turn fuel off in the fuel tab.

And reduce the charge termination some more. It ends very fast. Sit it to a lower figure for next time. Its 240mA now? Set to 180mA. Then test. Your cells reach full very easily. And you can reduce charge volts to 3.550 or 5.575 too if you wish, as its kinder to the cells long term.


Ok, I take note! Thank you!

Now the challenge is to get this into the small space of the chair. Approximately 250mm x 380mm x 270mm... czy
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