PINNED - Lithium battery conversion/info

Power wheelchair board for REAL info!

POWERCHAIR MENU! www.wheelchairdriver.com/powerchair-stuff.htm

Re: Step by step lithium conversion?

Postby nandol » 13 Mar 2015, 20:55

John,my new bm3 bat.box has 18cm internal width...15A fit,i think ? JUST HAVE TO POLISH 2mm at HOLDERS...?

whats odyssey pc1500 maximum width ? obg

http://www.evassemble.com/index.php?mai ... gh39pit9a6
User avatar
nandol
 
Posts: 1288
Joined: 04 Feb 2011, 22:48
Location: Lisboa,Poortugal

Re: Step by step lithium conversion?

Postby Burgerman » 13 Mar 2015, 21:12

Battery area in the centre section should be 174mm. That allows for 12Ah cell, plus orange building blocks, and connecting plates, 6mm allen screws, and a plastic/nylon insulating plug to fit between the sides without a massive short circuit and a fire!

(172 with screw tab)
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby nandol » 13 Mar 2015, 21:24

and a plastic/nylon insulating plug to fit between the sides without a massive short circuit and a fire!

John,please post a pic of that PLASTIC-NYLON for me understand better.obg
User avatar
nandol
 
Posts: 1288
Joined: 04 Feb 2011, 22:48
Location: Lisboa,Poortugal

Re: Step by step lithium conversion?

Postby Burgerman » 13 Mar 2015, 22:04

Image

The plastic orange blocks hold the cells. That's 172mm (+/- 1mm)

The end screws, are all X heads. These are hopeless, throw them away. Buy cap (allen) head bolts. Fit every one with a nylon cap as per the image. So if one comes loose, it cannot touch the metal centre section sides and cause a short circuit. They are all live!
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby Lord Chatterley » 14 Mar 2015, 15:09

nandol wrote:and a plastic/nylon insulating plug to fit between the sides without a massive short circuit and a fire!

John,please post a pic of that PLASTIC-NYLON for me understand better.obg


The exposed live terminals of the Headway cells will touch the sides of the metal battery box - so you need some sort of nylon or plastic insulation to prevent a short circuit. Do you understand? Say 'no' - if you do not understand. ;)

This is very important.

Can you provide some jpegs of your battery box?

Obg

LC
Lord Chatterley
 
Posts: 2286
Joined: 06 Jan 2010, 13:12

Re: Step by step lithium conversion?

Postby flagman1776 » 14 Mar 2015, 15:28

The thin plastic hold offs on the orange spacer blocks are intended as a safety devise to prevent shorted terminals. The plastic caps BM shows are a double safety & I applaud that. Or a sheet of a non-conductive material could be installed inside the box. Better safe than sorry.
It would be a b*tch to short out our chair after putting so much work into it.
flagman1776
 
Posts: 1907
Joined: 16 Nov 2012, 16:28
Location: Rhode Island, USA

Re: Step by step lithium conversion?

Postby Burgerman » 14 Mar 2015, 16:01

BEFORE CAPS BATTERY PAGE
http://www.wheelchairdriver.com/BM-MK3- ... rchair.htm

BEFORE CAPS PICTURE
http://www.wheelchairdriver.com/images- ... ry-700.jpg

AFTER CAPS
http://www.wheelchairdriver.com/BM3-con ... medium.jpg

AFTER CAPS
http://www.wheelchairdriver.com/BM3-con ... air-11.jpg Even bigger and clearer...

Notice the screws in the ends of the headway cells each have a black nylon hammered in CAP designed for the allen screws.
There are 78 cells. So there are some 156 caps to hammer in! CHECK EVERY BOLT IS TIGHT before you do this. Most people miss a few and have balance problems.

These are available as trim parts for motorcycles, cars etc. They are a tight fit into the head of the bolt. If the screw comes loose, it still cannot touch the metal sides of the centre section.
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby nandol » 14 Mar 2015, 19:59

obg fellas...with 180mm internal bat.box i might stick 15A headways (just have to cut 2/3mm of does Orange pics,on each side)
next monday i`ll contact a tech college 120km norte of lisboa to see if the engineer and teacher can help me out doing assemblage...ivanov no compreende much about litio :(
User avatar
nandol
 
Posts: 1288
Joined: 04 Feb 2011, 22:48
Location: Lisboa,Poortugal

Re: Step by step lithium conversion?

Postby Burgerman » 14 Mar 2015, 21:14

180 not enough.
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby Burgerman » 15 Mar 2015, 00:13

Apart from 180 meaning the actual terminals will touch, the blocks will all need to be trimmed down, and they are also taller so 42mm? per cell rather than 40 with the blocks.

For 24V 108Ah you need a battery that is 72 cell.

72 means 72 12Ah cells. And 108Ah. (more than double+ your old battery).

That's 6 cells tall, and 12 cells long.

That's 6x 40mm tall, and 12x 40mm long.

This means you need to measure carefully for a battery that is 240mm tall. And 480mm long. And 173mm Wide.

_____________________________________________________

My battery is 13x 40mm long. And 78 cells. So is 520mm long.
If you have 520 long space you could fit 2 extra cells on the top, for 80 cells total. Under the seat.
That means you could build an 80 cell 120Ah battery...
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby steves1977uk » 15 Mar 2015, 11:32

What sizes are the cable sleeving? And would 12 core trailer cable be ok for the balance cables on the chair side to the female connector?

I have some 8 awg silicone cable that I'm currently using for the charge cables, I'm guessing this would be too big for the power pins on the 13 way plugs?

Steve
User avatar
steves1977uk
 
Posts: 2384
Joined: 20 Oct 2011, 21:47
Location: Wells next the Sea, Norfolk, UK

Re: Step by step lithium conversion?

Postby Burgerman » 15 Mar 2015, 11:44

Trailer cable too heavy. You wont get it into the connectors with a couple of 12 gauge charge cables. Use the same stuff the balance wires are made from or very slightly larger. Use silicone charge cables. EBay. Use 12 or 15mm sheath and large heatshrink... Use inline fuse inside heatshrink soldered in the charge cables. Or just be careful...

And much care and thought and work neat!

http://www.ebay.co.uk/itm/Braided-Sleev ... 0088799839
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby nandol » 15 Mar 2015, 21:09

Lord Chatterley wrote:
nandol wrote:and a plastic/nylon insulating plug to fit between the sides without a massive short circuit and a fire!

John,please post a pic of that PLASTIC-NYLON for me understand better.obg


The exposed live terminals of the Headway cells will touch the sides of the metal battery box - so you need some sort of nylon or plastic insulation to prevent a short circuit. Do you understand? Say 'no' - if you do not understand. ;)
This is very important.
Can you provide some jpegs of your battery

yep,got it :)
User avatar
nandol
 
Posts: 1288
Joined: 04 Feb 2011, 22:48
Location: Lisboa,Poortugal

Re: Step by step lithium conversion?

Postby shirley_hkg » 16 Mar 2015, 02:23

shirley_hkg
 
Posts: 2363
Joined: 31 Dec 2010, 13:42

Re: Step by step lithium conversion?

Postby maker102 » 17 Mar 2015, 16:53

The guy I have helping me with my conversion is on vacation for two weeks. I just got the batteries in yesterday and am chomping at the bit to get started. With me having to let the batteries set for at least two weeks I am going to try to get them Charged. I would appreciate it if someone could look over and tell me if I have all the setting correct. I plan on charging them 6 at a time positive to positive, neg to neg for all 6 batteries. I will be using the EOS Hyperion 1420 iNet 3 charger with the following setting:

Battery Type: LiFe
Cells: 1 each 3.3 volt Cutoff Timer: 300
Battery Capacity: 120000 mAh Pre Peak Delay: Not Applicable
Charge Current: 20 amps Trickle Current: Not Applicable
Discharge Ampere: 3.0 TCS Capacity: 100%
Discharge Volts: 3.6 TCS End Action: Continue
Peak Sens: Not Applicable TVC Adjust Voltage 3.600: 0 mV
Cutoff Temp: 50 C PB Batt Float Voltage: Not Applicable
PB Batt Charger Voltage: Not Applicable
Set Store %: 60

Thanks Carl
maker102
 
Posts: 72
Joined: 18 Mar 2013, 02:58
Location: Illinois

Re: Step by step lithium conversion?

Postby Burgerman » 17 Mar 2015, 19:05

If you have the patience charge one at a time. After charge ends, leave on charge after the end as it beeps at you for 30 mins.
Set:


Battery Type: LiFe
Cells: 1 each 3.3 volt Cutoff Timer: OFF
Battery Capacity: 12,000 mAh Pre Peak Delay: Not Applicable
Charge Current: 3 amps Trickle Current: Not Applicable
Discharge Ampere: 3.0 TCS Capacity: 100%
Discharge Volts: 3.6V TCS End Action: Continue
Peak Sens: Not Applicable TVC Adjust Voltage 3.600: 0 mV
Cutoff Temp: 50 C PB Batt Float Voltage: Not Applicable
PB Batt Charger Voltage: Not Applicable
Set Store %: 60

Or GROUPS of them together in parallel, and adjust capacity from 12,000mah to 12,000 x however many cells in a group. As its faster.

Then immediately separate every cell. And number them. And store them for a week or longer.

Then charge 1 at a time, set to 12,000mah and see how many mAh you get back into each one. It will not be many. Maybe 10 to 100mAh before they are full again.

Group them together so that all these mAh figures add up to the same in each parallel group of cells so that the same amount of total mAh will be lost when sat in storage. This way subsequent balancing will be faster.
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby shirley_hkg » 21 Mar 2015, 09:42

:( HEADWAY site is still selling obsolute 3.85V over-charge protection BMS. :twisted:
Attachments
Screen01.jpg
Screen01.jpg (249.44 KiB) Viewed 4571 times
shirley_hkg
 
Posts: 2363
Joined: 31 Dec 2010, 13:42

Re: Step by step lithium conversion?

Postby Burgerman » 21 Mar 2015, 10:21

As are many other places. That's just a reseller/battery dealer.

I use 3.55v, there is absolutely nothing up there apart from killing cells fast. The only reason they suggest 3.65 charge voltage is because it is an overcharge. That naturally balances cells slightly, helping the crappy 100ma BMS balancers out there. That one doesn't even reach 40ma until the cell is at 3.7V! It will certainly help battery sales!

You may also notice they have continual balance and not just above 3.4v which unbalances the pack in the middle all day long, And the balancer takes a small current from one set of cells continually to power itself. Best to throw them away.

Most current hobby chargers have 1 to 3 amp balance.
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby intransient1 » 21 Mar 2015, 21:48

Hi Burgerman,
I would be very interested in lithium battery conversion, I am lucky if I get five miles with mk agm.
Thanks intransient1
intransient1
 
Posts: 9
Joined: 10 Mar 2015, 22:20

Re: Step by step lithium conversion?

Postby Burgerman » 21 Mar 2015, 22:36

What size AGM? If these are full sized GRP 24s they or the chair have/has a problem.
I am fat! And get about 14 miles before they stop... (6mph chair)
Or are you just driving 5 miles and looking at a few lights gone out?
Maybe they are defective. Maybe the chair has a problem. Maybe they are not charged correctly.

73Ah? You ACTUALLY get around 45Ah from a set of those before you stop. (Look up Peukert, and voltage drop under load due to resistance and surface charge). MK gel specs here. AGM is a bit worse. http://www.wheelchairdriver.com/MK3.pdf
Or 140 Mins at 25A before dead (10v). But your chair stops well before this due to low voltage.
A 6mph chair takes 16 to 20A at 6mph if its healthy - so it should run for 2 hours and a half. (at 6mph that's your 45Ah used up). And so approx. 16 to 18 miles. If you don't get this you have a problem. (Hills, grass, lots of turning, flat tyres, or puncture free tyres, all have a detrimental affect.

You can get the full 108Ah from a 108Ah lithium pack, (72 headway cells) and so get 108 div by 45Ah = 2.5x the range.
Its actually possible to fit 120Ah (80 cells) too. That's 120Ah or about 3x the range. So 40 to 50 miles.
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby funkykeyboard » 08 Apr 2015, 12:52

Is there a diagram for the balance leads for the burger man four wheelchair, for connecting the 13 cells of the wheelchair batteries, to the Hyperion charger please?
funkykeyboard
 
Posts: 443
Joined: 22 May 2010, 15:45
Location: Southport, PR8

Re: Step by step lithium conversion?

Postby Burgerman » 08 Apr 2015, 15:59

I thought you had 24V setup (8 cells)?

Same as 8 cells, but you use an extra 7 wires/taps/connections on the charger.

Same as all the hobby packs.

Wire it as 1x 7S and 1x 6S to each charger cell tap input.
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby Burgerman » 09 Apr 2015, 15:58

Image

Woodys drawing for a 4 cell 12V pack.

You do the same with whatever number of cells you have.
Here 4 cells and a standard connector as used in the hobby world for the charger.

The hyperion 1420 has 2x 7 cell capability.
The PL8 has 1x 8 cell capability. (so I use 2 of them)

So a Hyperion needs a 7cell batt and a 6 cell battery to make 12 cell total. split across 2 connectors.
A PL8 needs either the same, or, 8 cells on one charger and 5 cells on the other.

All hobby lithium batts are wired this way.
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby funkykeyboard » 11 Apr 2015, 17:00

Burgerman wrote:I thought you had 24V setup (8 cells)?

Same as 8 cells, but you use an extra 7 wires/taps/connections on the charger.

Same as all the hobby packs.

Wire it as 1x 7S and 1x 6S to each charger cell tap input.

this is NOT for my life stand wheelchair with lithium batteries, this is for my wheelchair I am basing upon your burger man four.

The guy who's doing the wiring for me said.
It's just the order of the balance leads go into the Hyperion charger as it has 2 leads each A&B with 9 wires. You can ask if you want but just need to find a diagram form it. It's annoying as it's been a pain getting the 6 cell ones working now this one has 13 cells.

So I gave him your diagram, and he said

No, problem is getting the Hyperion to see all 13 cells. That diagram is for the balance lead for 8 cells and have already built them. Got some time this week so will see if I can get it sorted.
funkykeyboard
 
Posts: 443
Joined: 22 May 2010, 15:45
Location: Southport, PR8

Re: Step by step lithium conversion?

Postby Burgerman » 11 Apr 2015, 17:42

Well he has already done 8 cells, so just carries on across the B connector as he did before.
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby Burgerman » 19 Apr 2015, 13:47

The good news is that I got them to see a few issues with the Revolectrix Cellpro PL8v2 charger, and they are looking at around 20 updates, bug fixes, to LiFePO4 (A123) charge algo changes and true float stage, for lead, in total.

But for LiFeP04 they are adding lower termination currents, longer time-outs, greater cell mV differences before errors, multiple cell count error issues, and low voltage error issues, but more importantly they are adding a 3.400V balance start option which was not available. Look out for new firmware soon!
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby steves1977uk » 19 Apr 2015, 17:33

Good to hear they are fixing issues with the PL8v2. Why don't they release the firmware as a beta version as I would help in testing it out.

Steve
User avatar
steves1977uk
 
Posts: 2384
Joined: 20 Oct 2011, 21:47
Location: Wells next the Sea, Norfolk, UK

Re: Step by step lithium conversion?

Postby Burgerman » 19 Apr 2015, 21:17

Well probably because there's a lot tech changes apart from the addition of a new voltage selection on balance start.

For e.g. I charge a lot of lithium ion batteries. Those go to a lower voltage, so auto cell count gives issues, and it thought they were "under voltage" and gave errors. And there are under and over voltage, and cell count issues on lead, and trickle (which can be used in correct time limited fashion) on lead acid charging but there is a voltage limit which it exceeds and gives errors.... And a current runaway on CV stage on some batteries that isn't monitored etc. And lots more. I have been discussing all of this for months with one of their expert beta testers.

They are sorting much of it out. Went through all of this once already with Hyperion! But now they know they will fix at least most of it. Some they wont fix, for safety reasons. We are all tarred with the same dummy brush. EG CV timeouts when charging certain cells without balance connected. Overall timeout limits on some batteries. etc. But they are getting there. So far its taken 4 months!

There's also some firmware and software bugs. For e.g. the parallel charge option doesn't change the termination end point. The charge to c/3 c/5 c/10 c/20 is supposed to be say c/3 = 1/3rd battery capacity if capacity is actually entered. Its not. It is 1/3rd CHARGE Amps! And once trickle is enabled for lead it cannot be turned off.

There's more too. Beats me why I can use it for 1 week and find at least 20 charge problems and logic errors, software bugs, etc. and yet the rest of the world don't see any problem in many years previously!

Which is why sending out betas to normal users is pretty pointless. Its already a beta, but nobody knew there was anything wrong.
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Step by step lithium conversion?

Postby funkykeyboard » 20 Apr 2015, 15:46

Oh well, I don't know why, and neither does my mate Danny. However, the Hyperion charger will not recognise all 13 cells of the battery pack I have produced for my version of the burger man 4. He got it to recognise 11, and then the next day it wouldn't recognise any. So much so, he thought he had bricked the Hyperion, but when he brought it round to mine to try on my life stand wheelchair, it recognised and began to charge all 8 cells no problem.
He said he is prepared to keep looking, but he has no idea how to move forward from this problem.
As an alternative way round the problem he is proposing I get these;
This is the BMS..

http://eclipsebikes.com/lifepo4-432v-ce ... -1062.html

This is the charger...

http://eclipsebikes.com/lifepo4-battery ... -1037.html

Unless anybody can make any concrete suggestions, I can't see any other way round.If people want to propose a better BMS and charger, thank you.

By the way, I trust this lad, Danny. He is genuine, and trying his best, isn't just doing it for the money he is being paid.

And I am aware this BMS is only 12 cells instead of 13, so we will only be using 12 cells in the battery pack instead of the 13.
funkykeyboard
 
Posts: 443
Joined: 22 May 2010, 15:45
Location: Southport, PR8

Re: Step by step lithium conversion?

Postby Burgerman » 20 Apr 2015, 16:56

Obviously you need to find the problem. Sounds like you have a cell balance connection wiring or connector issue.
This stuff isn't plug and play or easy. It takes a little care, and attention to detail.

I don't have a BM4...

A BMS will cause problems - wait and see.
http://www.wheelchairdriver.com/BMS.htm
And I am not alone in this
http://www.electric-cars-are-for-girls. ... stems.html

That one only allows 60A before you stop... I presume you are using a Roboteq? That can need up to 300A.
It allows cells to repeatedly reach 3.9V while trying to balance with a tiny 100mA current... Hope you like buying cells, and rebuilding batteries.

Just to start with.

And a 4A charger? Lets just do some quick maths.
Lets say 108Ah pack?
That's around 28 hours to charge.
User avatar
Burgerman
Site Admin
 
Posts: 45261
Joined: 27 May 2008, 21:24
Location: United Kingdom

PreviousNext

Return to Everything Powerchair

Who is online

Users browsing this forum: hank, salixfire, snaker, woodygb and 48 guests

 

  eXTReMe Tracker