PINNED - Lithium battery conversion/info

[ex-Gooserider]

Why not use 100ah batteries such as these?
http://www.evpst.com/productshow.asp?id=136

Thx

Same problems as the other "monoblock" batteries mentioned by other posters - low C-rate charge / discharge, and apparently a built in BMS judging by the listed specs...

ex-Gooserider

[Burgerman]

As above. Physically too big, only 1.5c rated. So will not work.

[astromutt]

Hi all,

just joined the amputee clique and was given a Quantum 600 powered chair that I need to refurbish. I was wondering the best replacement setup for 2XNF22 12volt deep cycle Batteries currently in place.

Thanks in advance

Cheers and Happy New Year to all

[Burgerman]

Normal user, normal undemanding chair,with stock programming the oem MK gel is the only sensible option.

[C400Driver]

I'm wishing to apply this system for my Permobil C400.

Is it possible?

[Burgerman]

Which system? Build your own Headway pack? Charge via a powerful hobby charger? And monitor low volts via a small hobby buzzer, build own loom, charge and balance leads?

Yes its possible on any chair. But you need to learn some stuff, be capable of making looms up, soldering, understanding what you are doing. So yes - if you understand.

[popschief]

ATTN:
John, call Boeing right away. They need help. http://goo.gl/qdgcg
bp

[Burgerman]

Is that a dodgy cheap on board BMS I am seeing???

[bruuu]

Could this address be the answer. Their batteries have a computer control chip preventing them from over charging or undercharging. They are a straight swap. All you need is the correct charger and a shed load of money. http://www.lithiumion-batteries.com/

[Burgerman]

Every month I get to repeat myself over and over as to why monoblock batteries such as these are a waste of time...

I will leave it to someone else this time!
But, limited capacity means huge cost with little or no gain in range, inadequate BMS capability, and limited C rating made wirst by the small capacity, etc to name a few in this case here.

[Burgerman]

OK now I have time. Quick expolanation why it isnt suitable.

THis one http://www.lithiumion-batteries.com/pro ... attery.php
is the biggest one that will fit a high end powerchair that takes 70Ah lead batteries.

Its MAX continuous discharge (more than a few secs) is just 50 Amps. A high end powerchair can require 240 amps... So its internal BMS will chop the power and you stop dead.

Its only 50Ah so no range improvement over the lead battery.

It uses a built in one size fits all BMS that isnt suitable for powerchairs and will cause the cells to have a short life as it allows them to go to too high a voltage as you charge. Its a quick and dirty way of selling lithium to the public that dont want the complication or dont want to know the technical stuff. Anything for a profit. Lithium isnt simple.

All for 1200 dollars! X2

[robnnorthaustin]

The prices for those batteries are absolutely crazy. From what I've read this is no longer "rocket science" so why is Boeing unable to source good lithium batteries with a 13 year lead time? If this isn't rocket science then why?

[Burgerman]

Crazy?

My battery in my BM3 chair, offers 3x the amount of stored power for 2.5 x the cost of the only Lead batteries that are close to adequate for my use. And at 45 volts, 15 mph and at least 45 miles range!

And just half the weight. Offering better off road, better range again.

And instead of one years use, I absolutely expect to get 15 to 20 years use. Why? Because 2000 cycles at the same 80 percent discharge level instead of only 400 cycles from the Odyssey. And since they are 3x the usable capacity, charge around 2 or 3 times a week only - do the maths! And no sulfation if less than fully charged.

And can be charged MUCH faster!

In real terms they are massively cheaper and have been for many years, even if they didnt offer improved performance, range, fast charge capability, etc just because they dont die every year. Thats why the rest of the world use them for 10 years in cars, bikes, toys, models, laptops, scooters, phones and other hand held gadgets, drills, the strimmer and mower in my garage, my cameras, and much more. Lead is Dead!

[LROBBINS]

Boeing did not chose a "standard" Li chemistry, but a new Li-ion design with even higher power density. As with other Li-ion batteries, it does not have the intrinsic safety of LiFePO4, as Yuasa and Boeing knew, hence the sealed box etc., but that was obviously not enough. Ciao, Lenny

[Lord Chatterley]

Crazy?

My battery in my BM3 chair, offers 3x the amount of stored power for 2.5 x the cost of the only Lead batteries that are close to adequate for my use. And at 45 volts, 15 mph and at least 45 miles range!

And just half the weight. Offering better off road, better range again.

And instead of one years use, I absolutely expect to get 15 to 20 years use. Why? Because 2000 cycles at the same 80 percent discharge level instead of only 400 cycles from the Odyssey. And since they are 3x the usable capacity, charge around 2 or 3 times a week only - do the maths! And no sulfation if less than fully charged.

And can be charged MUCH faster!

In real terms they are massively cheaper and have been for many years, even if they didnt offer improved performance, range, fast charge capability, etc just because they dont die every year. Thats why the rest of the world use them for 10 years in cars, bikes, toys, models, laptops, scooters, phones and other hand held gadgets, drills, the strimmer and mower in my garage, my cameras, and much more. Lead is Dead!

Tough cells too-

http://www.youtube.com/watch?NR=1&v=52h8IK0IdqI&feature=endscreen

LC

[nandol]

JUST MADE 20KM in 2 days most of them at10km per hr,and 1hr ago while here at pc chair turn OFF....because its lítio i had to call carer to press a button for rearm BMS....but NADA!! she press on it 2-3 times but chair=dead! she pick up batt.charger connect to chair+wall and...NADA!! NO charging light ON!!only the Wall power light was on.....
f...fellas,i was turning paranoid with it,ask her to press button again and only then charge light turns ON,uuuff
F.....Hell,tomorrow have to call autosil report the situation and pay attention to what they say....

thankfully the next days are warm and sunny...nandol at beach,burning the balls....need to relax,fellas !!

[nandol]

....Forget to say,when chair kaput i try the on/off pod button but NADA...reason why i had to call carer
obg

[Burgerman]

They are still messing about with a 50Ah battery? And Built in BMS? You will never get that working properly. And the BMS will kill your battery cells sooner rather than later.

[nandol]

They are still messing about with a 50Ah battery? And Built in BMS? You will never get that working properly. And the BMS will kill your battery cells sooner rather than later.

John,speak on phone today with them...they JUST want me to test the battery the way it is now,and for a while...
in the futur (after the cursed chair is ready..?? ) they will do a ++powerful battery to me..

this 50A bat.is good for eg: the "human appendix´s" that live here and use elec.chairs just in neiborhood...actually some need a carer just to cross street to go at grocery or kiosk..thanks god,for do not make me that way,fodasse!! rather cut my balls!!

[Burgerman]

But even if they get it to work with a dumb charger and modified BMS etc its ultimately pointless.

Because its way more money, will always be less reliable (bms issues) as well as having short cell life (Low C rate and BMS charge issues) and the same range as the lead batteries they have already... Why bother?

It will always be a worse option unless done properly, with more than double the capacity, and with higher rate cells, and without a generic BMS etc.

[nandol]

sure it is John,but now they want me to test the way it is(dunno,the purpose?)and they´re friendly,and if i ask a system like yours they built to me..(we already speak about it,months ago) and they have hands,i dont,and have tech skills,i dont.....
so John....what do i have to loose?
obg

[Burgerman]

Lots of time and breakdowns?

More importantly what do they hope to achieve? It will only ever perform as a lead battery at much greater cost with more problems.

[Ramblin Granny]

I would but don't limit to Lithium phosphate. Having used Li * in ebikes and scooters, the advatage is over the top.
Granny

[Burgerman]

Been using lithium xxx of all types in hobby stuff, like helis and quadcopters, planes etc since the 90s. Been using them in tools, household appliances, drills and the like for almost as long. But the only lithiums I would feel safe sat on top of, are LiFePO4 cells.

All of the rest, including laptop type batterues as used in the travelscoot, can burn very violently with a charge or casing damage issue.

Now a tiny laptop battery, isnt so bad. But its typically very low Ah. Travelscoot battery is just 12Ah, and even so is or can be dangerous. I really wouldnt want to be sat on 100 Ah+ of those types of lithiums...

So as far as I am concerned its LiFeP04 only.

This is a small laptop battery overcharged. The same type is in a travelscoot, but about 6 times bigger. http://www.youtube.com/watch?v=tC0UWIYswKI

http://www.youtube.com/watch?v=pizFsY0yjss another

Imagine 100Ah of that under the seat of a powerchair with a user that cannot get off it. This is why use of SAFE LiFePO4 is important.

[Ramblin Granny]

Found out today that shoprider has a LI xxx battery system chair. Still weighs 93 pounds.

Granny

[Burgerman]

Thats because wheelchair companies do not know how to fully take advantage of the higher C rate the newer lithium batteries allow. They just swap 24v for 24v, and sadly usually Ah for Ah. What they SHOULD be doing is using hight rate cells, so that they can use a higher watt hour, similar Ah, higher voltage better efficiency pack, with either thye SAME speed with lower gearing, and much better range, or the same gearing, higher speed with no loss of torque, and better range...

Swapping to lithium just because its easy does not gain much if anything. But it allows massive gains if they do it correctly. But this is powerchair companies we are talking about. They still build cheaply made crap from iron girders, and sell them for telephone numbers with 20 year old technology. Ie Brushed motors, low voltage, iron frames, lead batteries, tubed tyres, etc etc...

[Ramblin Granny]

Many e-scooters, e-bikes and even e-cars are using Lixxx batteries now. Just a matter of time until China or the Japanese come up with a modern wheelchair. Saw a proto type last year that really looked cool.
Was called a person transportation device, not a wheeled chair.

[Ramblin Granny]

Here is one-- http://www.falconev.com/E-Runner2.html Just design a chair around it<g> The Asian on I saw was like a cone shape and one sat in it. Loved the looks of it.

[Sully]

Those are probably practical for a lot of people in large cities, but the power source is what is so great. 20 miles @ 12 MPH and really small capacity and sized batteries, or power source. That is the beauty of it all.

[PowerHungry]

BM

A quick question, suppose I was to get lithium batteries, but instead of 78 cell pack I got 39 cell pack and used quickie groove 8.5mph motors, could I get 10mph speed out of chair as 15mph for me is to fast (i would fly out the chair lol) and would the range be decent still?