PINNED - Lithium battery conversion/info

[Burgerman]

That will work if you only want a 6 cell battery.

The cheapest place to buy the 40A 8 cell one is the Singapore shop...

http://www.store.revolectrix.com/Produc ... Lab-8_1029

That's about 125 pounds...

You will likely want to connect to your chair to charge and balance through one connector, and use something like this:
http://www.in2connect.uk.com/combinatio ... ctors.html

Shell size 3, 9W4 and a couple of plastic shell covers. So only one connection. Which means you likely need one of these too CP8SEXT36 PL8 36" extension 4 Cellpro (JST PA) PowerLab 36" Extension Cable

[terry2]

BM I've just had a great price for the batteries from a UK shop(same price as china).
Trouble is I won't have the cash for the charger and wire and stuff for a few months. Will the battery's be ok not being charged\left in the box?


Finally getting somewhere now

[Burgerman]

Should be. Depends on initial state of charge. They are best stored at about 50 to 60 percent charged. And that's how they leave china.

[Burgerman]

http://www.ebay.ie/itm/Terminal-block-2 ... 1351598679?

Those of you building hobby charger / lithium powered chairs and scooters may find this useful. Stick one of these on the chair, and you have 9 balance wires for an 8 cell 24V pack, and 16 left over for charge currents. Say 8 pos pins, 8 negative pins. Each pin is good for about 3 to 5 Amps continuous lets call it 4.

So you can safely charge and balance through one connector at up to 32A if you want. Or a bit more.

Just make up one lead with 2 fused high current 4mm Banana connectors, And 9 balance wires and a balance plug at the charger end and a single 25 pin Sub-D at the other. Use quality connectors... For any 8 cell charger like Hyperion. Pl8v2 etc.

I am just about to do this with 2 connectors to let me charge my 13S 45V chair with a pair of Revolectrix PL8v2 chargers. And am about to fit a lithium pack to my 24V BM2 chair.

Like this:

Code: Select all

 BM3 25 PIN TO FMA PL8v2 Charger combined balance and charge connector.

+ and - is power.
Numbers are balance connectors.

Looking at powerchair connector where - is no. 1 top left:
 
   
25 PIN SUB-D CONNECTOR - CHAIR SIDE:

    - - 0 1 2 3 4 5 6 7 8 + +    13 pins top row
     - - - - - - + + + + + +     12 pins bottom Row

[Burgerman]

These arrived. The tracks on the board don't look 3A capable to me... So not so sure. May be better to just solder the connections directly to the Sub D connector. There's never an easy way...

[steves1977uk]

How about these connectors BM.....

http://uk.farnell.com/norcomp/681s13w3103l001/d-sub-combo-plug-40amp-13way/dp/2294355 and http://uk.farnell.com/norcomp/681s13w3203l001/d-sub-combo-receptacle-40amp-13way/dp/2294356

Was thinking of buying a couple of these for a one plug solution.

Steve

[Burgerman]

Those will work too. Better probably. Was looking at those myself. But I have a draw full of the plain ones. May even order a set. They do a 37 pin sized one that has 5 heavy contacts. So one connector can be used for 2 separate batteries or my 13S setup.

Still not sure exactly what is best. Trying to make it all interchangeable between chairs and chargers.

[steves1977uk]

I know how you mean BM as I have plastic boxes full of plugs and cables

On a side note, is it ok to set the max amps on the PL8 to 40A on the supply tab in CCS? I have my digimess PSU repaired and want to make sure I don't blow it again

Steve

[Burgerman]

Mines set to 40. And amps wound up full. It actually reaches 44A charging lead batteries directly. Volts set to 27. No problems charging flat out. We will likely see a new large preset soon with a 3.4v balance setting.

Don't use the lipo setting set to a lower charge voltage as it goes into "safety" charge at half an amp if cell balance exceeds 150mv... Use this one:



I ordered some of those connectors. Actually similar ones. The ones you linked to are not designed to solder wires on but to a board. I think?
These are the right ones anyway in case... :

Manufacturer: NORCOMP
Order Code: 2294341
Manufacturer Part No 680S13W3203L401


Manufacturer: NORCOMP
Order Code: 2294339
Manufacturer Part No 680S13W3103L401

And again really not cheap!!!

Attached preset. Its not a zip. Del .zip from the file name.

[Williamclark77]

I look forward to what you come up with because I'll have to do something similar eventually. I haven't looked into any other solutions yet. You could save me he fun of researching

[Burgerman]

All ordered, will be super neat and reliable.

To charge a greater than 8 Cell battery:

You can LEAVE your battery connected as one big 13S or 14S battery.

As long as you charge it with 2 separate PL8v2 chargers.
You just need to be sure that each one is correctly connected via these 2 connectors.




8 balance leads for 7 cells, and 2 thicker 12 AWG charge wires.
So you will have 2 leads, 2 connectors, cable tied as one lead. It doesn't even matter which is which.
So 2 attached to the chair.
And 2 on your charge cable.

untitled.png (71.25 KiB) Viewed 15678 times

http://www.digikey.co.uk/product-detail ... ND/3078433

And matching male half. With 2 alloy covers.
http://uk.farnell.com/norcomp/680s13w31 ... pd-r2-acce
http://www.canford.co.uk/Images/ItemIma ... 079_01.jpg

These give you 40A charge capability, and 10 pins for balance each battery of which you need nine.

This works ONLY IF YOUR 2 POWER SUPPLIES ARE ISOLATED. Or there will be smoke!

Works fine in fact as I already tested it with temporary wiring.

[Burgerman]

I am using 2x 1200 watt power supplies
2x PL8v2 chargers
It was not cheap but no more Hyperions and so I thought I would splash out...

But I can now charge at 2400 watts or so.
Or 40 Amps. With 1 Amp balance. x2

You could charge from dead empty to 90 percent in about 1.5 hours or less!

TWO of these: http://www.ebay.co.uk/itm/USED-digimess ... 1650693897 Because they are bomb proof, and isolated. Floating output. This is essential.

TWO of these: http://www.revolectrix.com/pl8_description_tab.htm

This is an 8 cell charger. Use 2 in parallel. Its the best charger on the planet right now for reliability and power. And the only one with decent PC software. And its twice as powerful as the Hyperion. With more balance power. But its really not a cheap way to do it...

But it is good.

This means I have 1300 watts x 2 (2600 watts) charge capability.
Compared to a single 250 watts from a mobility charger.

1.5 hour charge.
Instead of 10 to 16 for a mobility device.

[Williamclark77]

So basically, you plug your two power supplies into two different wall outlets, your two power supplies into two separate chargers, and two separate chargers into two separate "banks" of your battery? I thought about that and it seemed like you would need to break the 13S or 14S connection where the individual banks were. I hadn't thought about it much. I have three Hyperion 1420i chargers still. Well, two since I smoked one, but it SHOULD be repairable also.

How high of a series cell count would that be able to charge? 16? I haven't had a chance to look at those chargers yet. I will shortly.

[Williamclark77]

Your last post wasn't there when I started my reply. I'll look at those chargers shortly. I would be scared to pull that many amps from a standard wall outlet for more than a few minutes at a time. It might trip a breaker!

I might would go up to 16S on mine if so. A big diode should protect the Roboteq from regen going over 60v.

It seems like you could get a Chinese company to build a "bms" that did nothing except when plugged into a power supply. Basically exactly as we do now with a Hyperion, just stays onboard, not powered on unless plugged into an outside source, and accepts a 120 or 240v supply from a wall outlet or xx volts from a power supply. No telling how many the minimum order would be to get them made though.

[Burgerman]

Most power supplies (many and almost all cheap ones) have the NEG tied to the ground pin. At the sub station this ground pin is additionally tied to the Neutral... This is the case with hobby, industrial, or computer server power supplies.

So the OUTPUTS of the chargers then have the NEG connections tied together even if using wall sockets on different houses...

So the chargers must be connected to a floating or isolated power supply.

To test, just measure the resistance between the NEG connections of your power supplies when switched off. Should be open circuit (very high impedance).

[Burgerman]

That way you can connect a "separate" isolated Power supply/charger, to each set of 7 or 8 cells even when connected up in the chair as one big single battery.

Each charger will be about 24v "different" to each other electrically but all plastic and isolated so it doesn't matter. As long as they are plastic cases, floating power supplies, etc. then its all fine. The USB connectors on the chargers are also isolated so can be plugged into the PC for control safely too at the same time.

On screen you just run two copies of the software. And you charge 2 separate 7 or 8 cell batteries. And get 2 graphs.

They even expect people to do this.

See: CONFIGURATION H on page 25/26

http://www.revolectrix.com/support_docs/item_1437.pdf

You could, if you fit a jumper connection, use G too.

[Burgerman]

2.6kw lithium computer controlled and monitored charging station... Unlike the Hyperion chargers these can only do 8 cells (up to 24v systems) so 2 are required if you use 36 or 48 volt setups..

This can put back DOUBLE the entire stored power quantity of any normal lead powerchair in under an hour! 40Amps x 28 Volts x 2 chargers. But is still controlled enough to also charge a single tiny watch battery safely.

Or 2.6kwh of energy in 1 hour... That means It can replace:
45 Miles of range in 1.5 hours into a large capacity Lithium battery.
22 Miles of range in 45 Mins.
11 Miles in 22 mins.
5 Miles of used power in 10 mins.

Provided your wall socket can give 3.1kW output. As each power supply needs 1550 watts.
In the UK that's possible. Every socket can in theory support 3.1KW max.
Not sure how that works in other countries? This is the most power you can get out of the wall. It will charge a full sized EV faster than the chargers they come with!

[LROBBINS]

In Italy it won't work. We have 10A/220V (2.2kW max) and 16A/220V (3.5 kW max) sockets, but the total available in an ordinary household service is 3.2 kW. We have to time the use of major appliances - if we forget and start the clothes dryer and microwave at the same time, we get to go out and reset the main breaker. One can get a 4.5 kW service, or even a 3-phase service, but they are very expensive.
Ciao,
Lenny

[Burgerman]

Then you would need about 6 old lead batteries and a small charger sat outside somewhere as a reservoir. Or charge a bit slower...

3.2kw total isn't much. An electric shower is 8.5kW! A dryer or water heater alone takes 3kW. I think the main fuse here in the UK is 100A or 150A in a normal house. And those seem good for much more in reality. Since they can only be changed by the power company. You never hear of one going bang...

Its probably one of those job creation schemes like never adding enough digits in phone numbers and being "surprized" when they run out of digits... Every 10 years. So how are they going to cope with electric cars? Those use up to 9kw chargers.

http://www.nissan.co.uk/GB/en/vehicle/e ... ttery.html

Even the toy Nissan Leaf has been upgraded from 3.3kW on-board charger to a 6.6kW one.

>>>we get to go out and reset the main breaker

Tape...

[LROBBINS]

Tape ...

Nope, the main breaker is part of a network-connected watt hour meter; trip is actually electronic and will happen even if the lever is held up.

Italy has virtually no in country fossil-fuels, and the cost of all sources of power is quite high, so there are some fairly strong arm approaches to encouraging people to use as little as possible. Of course, if you have to do n loads of laundry, you have to do n loads of laundry, but you are more likely to run full loads if running the washer means you can't turn on anything else larger than a few watts.

On the other side, Italy is now #2 in Europe for electricity generation from renewable sources; a large part of that hydro and some from geothermal, but wind and solar farms are becoming more common. We certainly have sun and wind in abundance.

Electric car charging poles are starting to appear on city streets - there are at least 6 in Siena at this point that I've come across, probably more.

Ciao,
Lenny

[Burgerman]

Have you looked into solar? My cheap Chinese DIY setup more than covers my electricity in summer, and helps a bit in winter. Its 9AM and low sun but right now I am seeing 1.2kw incoming from that free atom bomb in the sky. That's happening when I am in, out, using power or not. Its crazy not to capture free power. Especially where you are.

[LROBBINS]

I'd consider solar but for the fact that we live in a building with five apartments and (1) I'd never get our co-owners to go along, and (2) given that it's a condominium arrangement we'd have to meet government regs which would preclude a sensible system like yours (though the state would end up picking up 55% of the inflated cost).

[Burgerman]

We too have a "professionally installed" systems that costs double, work worse all connected in series, and then gets government (tax payer) hand-outs to help cover the massive inflated costs. That's what 99% of normal people do. Its the recognised way.

I just choose to ignore it and do as I wanted. Its my way...
As for legitimate? Who knows. Its not technically breaking any rules but is feeding into the grid at times. So its a grey area... Not one that the rules allow for. Theres no reference to this that I can find. It is just plugged into the wall like a laptop. With every inverter having a CE mark. But it certainly works!

Its basically taking the DC and turning it to AC and trying to lift the grids voltage to 265V average from about 245V which obviously it cant manage! So it does its best, and all the power feeds into the wall. If I turn everything off, then it goes into the street and up the wires to other houses...

[LROBBINS]

Yes, your system is the better way to go, but you don't live in the land of endless forms and approvals. I would probably not end up in jail if I put in a system without the required approvals, but you can be sure that I would eventually be forced to take it down and pay some hefty fines. (Or maybe not, depends on the bureaucrat's mood that day.) Ciao, Lenny

[wilsonintexas]

Question on the new charger and parallel charging using the Power 8 charger.
.... (trying to keep costs down....)

I am thinking about a lithium pack for a chair for my daughter. As always cost is a problem..... (I KNOW LONG TERM IT PAYS FOR ITSELF)

One cost is the charger..... at around $240 for one, that would be close to $500 if I need 2.

The manual has a section on parallel charging..... (some of us actually read the thing. )

So. It says I need to keep each pack the same... That means either

12S at 44.4 volts
or
14S at 51.8 (which is stretching the 50 volt controller...)

So several questions:
1) How well would it actually work using a single charger, if I split my pack into 2 sets with the same count and only one charger? I know charging time would double, but i think we can adapt for that..... if we charge nightly to keep it charged up.....

2) If I went to 14s, am I pushing the controller to far? (I seem to remember that the cells drop a little, so it would not be at 51 other than the first few minutes ..... I hope..

3) If I went to 12s, how much would I be giving up? (top speed, higher load on current because of slightly higher current)

Anyhow here is the section of the manual that I am basing this discussion on (from the power 8 manual.... )


Parallel charging takes advantage of the PowerLab 8’s high power output. After connecting packs using Safe Parallel Adapters, simply tell PowerLab 8 how many packs are attached—charge/discharge rates are automatically divided among the packs


PowerLab 8 can charge, discharge or cycle up to nine LiPo or A123 packs in parallel. Parallel operations can save a lot of time, but you must follow these rules:  Always use Safe Parallel Adapters (available at the REVOLECTRIX Web site). Never use standard adapters.  Connect only one pack per Safe Parallel Adapter. Daisy-chain multiple adapters!   Parallel operations using Safe Parallel Adapters requires that you connect both the balance wires and discharge wires to the PowerLab 8.   Always observe proper polarity!   Packs must have the same cell count.   Packs must be the same chemistry.  The best way to connect discharge wires in parallel is to stack the plugs on the safety banana cables like this:


Summary: parallel charging. Components:  1 PowerLab 8   1 power source   1 Safe Parallel Adapter for each pack (do not use standard adapters)   2 or more packs (above 9 packs in parallel, you are responsible for determining the charge/discharge current for each pack)   Optional FUIM3 for computer support 
PowerLab 8 mode (Normal or Expansion Channel): Normal.
PowerLab 8 maximum charge power: up to 672W charge to each of two packs charged in parallel using 24VDC/1700W power source.
Constraints:  1 pack per adapter.   Check pack polarity.   Same cell count for all packs.   Use discharge leads

.

[Burgerman]

Parallel charging doesn't need any special adapters or anything. Those just add fuses to a bunch of simple connections. And overcomplicates stuff... Those are really only needed for hobbyists charging lots of different packs in a hurry. Where they get it wrong!

You need only a custom charge and balance lead making up. Charger at 1 end, and 1 meter away the chair at the other.

But I wouldn't bother parallel charging anyway. With big batteries too much current will flow when you plug them together if they are at different charge levels.

If you use 12 cells you will have a very fast powerful chair. 14s is too many for the roboteq on deceleration during regeneration. I am using 13S only because I am mad.

Since you can charge 8 cells (9 without balancing which you don't want to do) at once then you either use 2 chargers. Or charge 6S and then 7S or 6S for the other half of the battery afterwards. 12S will mean 2X 6S Batts. BUT you can charge each one for about 2 hours from dead to full. So you could easily manage with just one charger... But being disabled isn't cheap, and then you have no backup.

1) How well would it actually work using a single charger, if I split my pack into 2 sets with the same count and only one charger? I know charging time would double, but i think we can adapt for that..... if we charge nightly to keep it charged up.....

72Ah battery X 2 if charged in parallel, is a 142Ah battery. At 40A charge you will get a completely discharged pack (say 50 miles of use) full in 3 hours and a half. If its half discharged (equal to 2 days normal use) then say, 1.7 hours to full.

2) If I went to 14s, am I pushing the controller to far? (I seem to remember that the cells drop a little, so it would not be at 51 other than the first few minutes ..... I hope..

Too much. Regen will give a shutdown and emergency stop probably.

3) If I went to 12s, how much would I be giving up? (top speed, higher load on current because of slightly higher current)

Are these the same 8.5mph AMT (Sunrise) motors I am using?
Then... At full speed with R-net you get 22V and 8.5mph. R-net keeps some for headroom for steering. That's 0.3863 mph per volt.

At a 3.32v per cell average typical working voltage from Headway cells, you get 43.16v with the roboteq full speed output with 13S like the BM3 chair so 16.67mph theoretically.
And so 3.32v = 39.84V with 12S. Or 15.39 mph.

In other words its going to be fast enough to be dangerous. You will try it and program it slower for your daughter! Range will be the same if the same number of total cells are used. You lose only speed.

[wilsonintexas]

Thanks for the prompt and well organized reply.

I will probably go with either 10s or 12s and se how it goes.... but that is still a way off.... still trying to get things organized.

I have 2 sets of 6.5 motors from some donor chairs. One set is in ok condition (4 pole) . I have yet to look at the second set.

My daughter is doing a lot better. A little over a year ago her femoral nerve was damaged during a procedure. She has a spinal implant to try and manage the pain. She can not get around the house without crutches some of the time. But still has problems with the leg swelling when she stands or is upright for any length of time. She recently started to drive again.... shich gives her some freedom. A chair will still give her more options when doing things outdoors. (like take the 2 BIG dogs out..... a connie corso and a Russian bear thing....)

I was looking for a 4wd for outdoor activities in Alaska, but she says that that is not needed yet.

So I will probably look to rebuild a more conventional chair to get more range and speed. and the ability to do some outdoor stuff....

She is a your adult..... ok at over 30 probably qualifies as a full adult, (but do not tell her I said so.... )

anyhow... when the weather breaks down here in Dallas I need to get up to my dads to pick up the donor chair and get going on this.

[Burgerman]

Don't underestimate the importance of range.

All those that are using lead batteries think that this is adequate. Mostly because many users don't really go far. But even most 30 year old are equally "happy" with the 15 to 20 miles that the manufacturers claim from lead. That you wont achieve in reality. Why?

Because they are accustomed to modifying their expectations. They don't ever just roam about "free" of worry.

So here in my own life for e.g. instead of taking the dog "on foot" so to speak down to the beach, and along it for 4 or 5 miles, and then home I use the van. Why? Because even if the total trip is 15 miles, you are never sure how much there is left. This restricts life, and restricts what you attempt to do. They "train" you not to attempt the things you naturally would do if getting back home wasn't a serious problem and a worry.

So by adding enough unrequired battery reserve, that the user gives out well before the powerchair range does, it actually improves your life.

The other night I was sat in my lead powered chair, looking at a battery gauge showing about 1/2 power left. Those things are not remotely accurate. So I am not sure. Having just got back from the town centre and walked the dog. And got a call from a friend to meet in a town pub about 3 miles away. I DIDNT go, because that's 3 each way... And some more wasted in the pub. And I wasn't sure it would make it back. So the 2nd half is worthless...

Most users are brainwashed by the actual chair to accept this state of affairs as normal and they don't think about it. Adding a Lithium battery that allows 3x the range, allows you to live your life rather than worrying or planning it around a battery.

The other advantage is that you can measure Ah used (or returned by the charger) on every charge. So you can clearly see to the mile how much you had left. With lead you cannot know because of the Peukert issue. You MAY get 50Ah from that 73Ah battery. But the next day you may only get 30 Ah before it stops. Depending on type of usage.

[wilsonintexas]

out of courosity, where was the bm3 for the trip to the pub? (NOT being anything but courious here.)

I fully understand the need for range, especially where se is in Alaska...... let's say that it is not remote, she does have a few neighbors..... but you are several miles out of town, down a side road a mile, then off onto her dirt road........ so if she got stranded, it could be a while before there was help. There is always the post man, once a day..... many of the people work in the oilfield, so it is not like they come home everynight. Her husband also works in the oilfield, so he is gone for weeks at a time, so no one to call at home.

But, first I need to get the parts together and get it working......

[Burgerman]

All polished and super shiny. I have 3 dirty lead powered chairs that I am wearing out, those are good enough for the salt encrusted and black silt covered wet streets we are having... Waiting for a month till the sun reappears!

Although I am sat in it indoors at the moment. Playing with settings. And looking at swapping front tyres for greater caster stability at daft speeds.