lithium battery power on lifestand LSC?

[funkykeyboard]

Sorry my posts are confused. That's because I don't what I'm talking about, and if I did, I wouldn't be here.

It turns out my batteries aren't correctly balanced. We are assuming that the percentage indicator on the balance mode, indicates the amount of imbalance?

Last night it showed 35% imbalance. It was on to 2 hours. It has been on for nearly 2 hours this morning, and it is still indicating 29% imbalance.

If there is a problem with the packing, there is no reason we cannot repack them, if that will resolve the problem.

[Burgerman]

>>We are assuming that the percentage indicator on the balance mode, indicates the amount of imbalance?

Not sure what you are looking at. It doesent read imbalance as a percentage. But in volts, to 3 decimal places.

If its the percentage charged on a PC screen? Then its all but meaningless. Works on LiPo very well but very innacurate on LiFe headways or CALB cells.

Plug in, connect balance cable. Choose the parameters I suggested above. Use the PC software. What are the cell voltages? Each one should be 3.600v plus/minus a tiny 0.003v once charged.

If its NOT charged, or balanced, then you need to charge each pair of parallel cells up FULLY at full power until the charger says they are done, and then another hour. Thats ONE cell at a time. At 3.600v...

Onl;y then can you charge them as a group and let the charger balance the cells.

[Burgerman]

1. Set the charger to charge SINGLE cell.
Choose 3.600v, 20 amps, set to continue, no time limit.

2. Connect charger to EACH cell, and charge up FULLY one at a time. When its full, it will read zero amps... And beep every few seconds.

Do this seperately for every cell. One at a time. It may take a long time if empty, or a couple of minutes if full.

Then connect up balance cables, and charge cables, make damned sure there are no loose connections and that its wired correctly. Then choose 8 cells LiFe, 20 amps, 3.600v, no time limit, continue etc.

It will now charge, for a short while, and at the end it will balance the cells. Leave connected after it ends, and it will keep beeping. Let it do this until amps falls to zero. It should not take long.

[woodygb]

sales@eclipsebikes.com
We could offer 8.5% off the price of the 12Ah Headway cells and also include the plastic cell holders & metal connectors free with your order.
The 12Ah cells are normally priced at £16.50 so minus 8.5% discount would be £15.10 each.

34 x 12Ah Headway LifePo4 cells (£15.10) = £513.40
34 x Headway Cell Holder 38120S / 38140S = £0.00
34 x 2 Hole Cell Connectors 38120S / 38140S = £0.00

Could you supply a pic/s of your lithium pack/s?..it might help in identifying any build probs.
I assume that you have 2 spare cells from the 34 that you bought? ...so 8 groups of 4 cells?

[Burgerman]

Charge the 8 groups that are connected in parallel seperately. So theres 8 sets to fully charge.

Make sure (thoroughly check) that every screw is tight. Twice.

[Burgerman]

After you do all of the above post. And read this carefully it should charge fine.

However.
DONT choose DISCHARGE or BALANCE with a LiFePO4 pack. That will UNBALANCE the pack.
DONT charge it as a LIPO battery. That will seriously damage the cells.
ALWAYS charge only, and this balances the pack at the end.

But it cant do this if they are say 10 percent different. Well it could, but it would take around 2 to 3 days...
This is why you fully charge each cell or parallel groups of cells individually first after you assemble the pack.

Then you will get something that looks like this below:

[Burgerman]

THIS is my 4 CELL LIPO battery from a model plane.
This is NOT LiFe as your pack is, so the voltages are different. Everything else is the same.

This is charging at 4.200v per cell. LIPO 4S
You need 3.600v per cell. LIFE and 8S

Now on this graph the charge has ended. But it is still actually balancing, and topping up with a small current.
Output current is charge Amps = charge current. Eventually this will drop to zero. So no more balancing or charging is taking place. You dont have to wait for this, you can drive away when it says charged. But I wait...

Percent = charge level, based on terminal voltage. It is at best a rough guide.
Yellow square is the 4 cells actual voltage at any time. This is deadly accurate.
Output Voltage is the voltage at the charger, (not at the battery, this isnt the same as wires have resistance.
Output capacity is either Ma returned or Ah returned depending on the battery size. Both mean the same thing. Here it says 1570, or 1.570Ah returned.
Pack resistance is wires, battery etc added together.

The graph shows green - charge amps.
Other 4 lines, one for each cell - volts. You SHOULD see something similar.

[Burgerman]

The important thing is that once charged, CELL GAP is at worst, say 0.010 of a volt. See on the image above, cell gap is just 2, 1000ths of a volt. This is normal.

[funkykeyboard]

Okay we aren't exactly sure what happened, but think it was this.


Fitted some auxiliaries stuff, lights, USB socket et cetera. These were connected to just one side of the batteries. (For groups of four cells on either side, in each pack.)

I didn't understand what the different tones meant. The charger was charging, and then peeping to indicate that it was balancing. I thought that was the end of the charge, and was switching it off.

I was out using the wheelchair, it indicated it was on a low charge, and before I got home, the wheelchair was only just about moving.

When I put the charger on, it didn't indicate they had fallen to low, but we think they'll was some damage.

Tried charging them individually, but it didn't seem to work. So we split the packs and mixed them 5050, so any damaged cells, would be spread equally between the two packs. That seemed to remedy this situation, and we could balance the cells properly.

Now have too see how these go over the next week or two.


-----------

for now we have left the auxiliary equipment disconnected. Have bought fitted to a voltage dropper, so when we refit the ancillary equipment it will run off the whole 32 cells.

[Burgerman]

Before you charge the pack, you *MUST* charge each cell individually, completely and totally for around an hour AFTER it says done.

Do every one. "Doesent seen to have worked" makes no sense. It either works or it doesent. If not find out why, fix problem before you continue.

If you DONT do the above you will likely never have a fully charged pack, and it will take up to a week or more to balance it. As soon as one cell gets full the rest STOP CHARGING as the charger throttles back to .3 of an amp. So all MUST be full before you charge it and therefore finally balance it.

Once you do this subsequent charges will be fast/normal.

I fear I am wasting my breath here. READ again!!! If you do not do this you will kill your cells. And have no range.

[Burgerman]

The "peeping" does mean end. It actually means about 99 percent.

When you say it read low while out, WHAT read low? What are you using to gauge "low"?

[funkykeyboard]

I am just using the gauge on the dynamic DX controller. Seems it's not pretty good

[funkykeyboard]

Before you charge the pack, you *MUST* charge each cell individually, completely and totally for around an hour AFTER it says done.

Do every one. "Doesent seen to have worked" makes no sense. It either works or it doesent. If not find out why, fix problem before you continue.

If you DONT do the above you will likely never have a fully charged pack, and it will take up to a week or more to balance it. As soon as one cell gets full the rest STOP CHARGING as the charger throttles back to .3 of an amp. So all MUST be full before you charge it and therefore finally balance it.

Once you do this subsequent charges will be fast/normal.

I fear I am wasting my breath here. READ again!!! If you do not do this you will kill your cells. And have no range.

it is difficult for me to explain, because I don't understand all this, I'm not the one doing it, it is the Danny boy you spoke to above.

I'm just trying to pass on the information, so people don't make the same mistake I did. Everything was running fine, until we put the auxiliary equipment on.

As far as I know, he did charge them all individually. But when he tried to balance them again, it wouldn't work. It is only since he has split them 50-50, that they now balance. (That's the story as I understand it. I will try to get him to explain it.)

[Burgerman]

But when he tried to balance them again, it wouldn't work.

If you took say 3Ah out of some cells but not others it WOULD balance them again. But at .3 of an amp. So it would charge normally until some cells were full. Then slow down and charge for at least 10 extra hours while it tried to rebalance the 3Ah you took out at .3 of an amp.

The peeping noise means it IS finished. And balanced as close as is needed. Its better to leave it a while but its not essential. You can use it at that point.

The cells are only damaged by dropping below 2.5v (2v claimed, dont try it) or above 3.65v. BMS systems allow this... Hyperion does not.

[Burgerman]

I am just using the gauge on the dynamic DX controller. Seems it's not pretty good

Tape over it.

That was designed for lead batteries, it has absolutely no clue what the lithiums are doing. It will not be linear, or even remotely accurate. If that says full, or dead, it could mean absolutely nothing.

Get a hobby cell measuring device, as I showed on a post here recently. That has a voltage read out for each cell. (or group in parallel). Its tiny, and has an ALARM that will sound if any cell goes below 2.7v.

Your meter on the powerchair is trying to compensate and "guess" for a lead battery that has Peukert and internal resistance losses. It wont even be a guide. Ignore it totally.

[funkykeyboard]

I'm sharing all this so that if anybody is doing the same, they can see the problems I've had.

New problem. We went with the Anderson connections originally, but they were too difficult, and too complicated for my PA's to plug-in and out easily. So we went for an alternative;


the blue one seems great. No problems with that. However, the other two do not seem robust enough for my PA's heavyhandedness. Sometimes the pins get bent, and now solder has come loose.

So we were going to use one of these because it has 15 holes, http://www.ivojo.co.uk/component.php?pid=Kramer_WX-1N , but apparently when it has arrived my electrician discovered it had some kind of switch on it, so only seven could be used at the time.

So my question in short, is, can somebody recommend an alternative?

[Burgerman]

ANY simple D plug as used on parallel ports etc.

http://www.ebay.co.uk/itm/9-15-25-37-P- ... 2ec468284c

[ex-Gooserider]

You need to carefully read any component's description and (ideally) the technical documentation - especially if trying to repurpose an item for something it wasn't designed for initially...

In the case of the computer plugs, it is worth noting that in many (most?) cases, the connectors use fewer wires than there are pins. They use connectors with more pins in order to get some level of only allowing the right stuff to be connected to the right places... However this means that cables may not have as many wires internally as the plugs have, or that plugs may not have as many contacts on the wiring side as they do on the connecting side...

In the case of the Kramer part linked to, it is apparently intended as a VGA plug - the standards call for VGA to use a 15 pin, 3-row, mini-D connector, but the actual VGA signal only uses about half that many wires for it's data (I forget the pinout off-hand and it's not worth looking up for this discussion) so they use a terminal block with only the required wires...

If you were to get just a regular 15 pin D connector, with solder pin contacts on the back, you'd probably have all 15 pins available, but you'd have to solder them in rather than just using screw connectors - which is better technically, but a bit fiddly as the working area is small...

Also IMHO a D connector is fairly fragile, and a bit on the light side in terms of it's wire size / current rating - I used to see a lot of them getting damaged when I worked at a computer place where we were constantly plugging and unplugging monitor cables... I'd personally be inclined to look for a heavier duty plug, possibly something like a Molex or AMP connector if you can find something in a non-locking configuration.....

(actually I'm rather surprised that your PCA's are having trouble with Anderson's or the connectors I'm seeing in your photo - seems to me like you have a rather clumsy / ham-handed PCA...)

ex-Gooserider

[funkykeyboard]

Could somebody please provide me a picture of your Anderson connector/cable/charger setup please?

The problem they had with the Anderson connector, was they found it hard to plug in and out. I don't know whether this was just fear of breaking something they had to tug particularly hard. Also, I'm sure this would get better as they become worn by use.

I think also be was a problem with the way we wired them from the charger to the Anderson connection. Looking at the way you have done it, may enable me to do a better job and make them more feasible than what I have.

At present, they are working again. After they were re-soldered. Going to see what happens.

I do appreciate everyone's help, thank you.

[Burgerman]

What size andersons?

50Amp ones, with PROPER tinned thin wall (hard high temp insulation) that are both crimped and soldered are impossible to damage . You can swing on the wires if there are enough of you, and they will snap somewhere other than the connector. Once you work out how to do these properly it will take you a couple of minutes max to do.

Yes they are hard to push together for the first few days and after that they wear in and its pretty easy.

http://www.wheelchairdriver.com/crimp-solder.htm

There are also handles available (ebay is fastest way) in the event you are weak!

[funkykeyboard]

My memory is not good on this. I will discuss it through with my electrician on Monday, and even try to provide some pictures.

To my memory, which could be faulty, the problem wasn't at the Anderson connection. The problem was the wire running from the charger. I think there was some kind of shorting going on. That's why I wanted a picture of the full set up, from charger to Anderson connector.

Anyway, I try and get a proper picture of what I had, and see if we can throw some light on the situation.


[As I say, it is difficult when you don't know exactly what you're talking about)

[funkykeyboard]

Typing badly from phone, whilst in bed.

Transformer died whilst charging on an extension cable. Recommend a better transformer please

[funkykeyboard]

Problem with charging, mentioned above, was faulty solder

[funkykeyboard]

It is the fusion 600 W adjustable power supply views that has blown to smithereens, so I cannot check what its specifications are. I have just read somewhere on the Internet 6A 250V fuse. Does this concur with what other people have in their machines?

[funkykeyboard]

Put new fuse in, blew instantly. Smells also. So DO need new transformer recommend please I'm

[Burgerman]

They do that it seems. Got several replaced under warranty.

Most people are using:

PC power supplies (server ones in series)
Industrial ones from ebay (I have 2 - work great)
Or fancy bench power supplies. Like my 40 amp, 30 volt adjustable one.

Or a set of old batteries and an old powerchair charger. Or a car...

See here for eg: I have one of these http://www.ebay.co.uk/itm/USED-digimess ... 27d26fddcb

24v 1000 watts http://www.ebay.co.uk/itm/1000W-24V-40A ... 4ac42ca3f5

Or smaller but adequate http://www.ebay.co.uk/itm/1000W-24V-40A ... 4ac42ca3f5

Super cheap 500 watts http://www.ebay.co.uk/itm/24V-20A-500W- ... 35b994ab3e

1500 watts 24v http://www.ebay.co.uk/itm/1500W-24V-62A ... 4ac424186b

[funkykeyboard]

I should have guessed from when I was discussing how noisy the charger was, and you asked "is it not the fan on the transformer"? But the problem is now obvious. The fan has never worked on the transformer.

[Burgerman]

You don't have a transformer.

Transformers are heavy, old technology. You have a switch mode power supply. Everything modern uses this now.

See here: http://en.wikipedia.org/wiki/Transformer

And http://en.wikipedia.org/wiki/Switched-mode_power_supply

[funkykeyboard]

I'm sorry, you're right, power supply.

Had to do everything on the run yesterday, as I was out and about. And as I had been out and about the day before too, my charge was getting low. So I had to jump in quick before you gave me all the information and order next day delivery on the fusion (I will get my money back for the other one).

When I charged it today, the batteries took CAPA 36,448mAH. As new the maximum capacity was 48,000mAH. Which would mean they were down to their last 15%. However, I have had my problems with the setup of these lithium batteries, and the maximum capacity might not be 48,000.

There is NOT much room left under the hood to fit much more stuff, that's why I was discussing the fitting of a battery usage meter. The problem is, if you don't know what the the current maximum capacity is, knowing how much has been used while you are out and about doesn't inform you how close you are to damaging the batteries, does it? Is there a way to work out (using the Hyperion charger) what your current maximum capacity of your lithium batteries is?

[Burgerman]

Yes. Fully charge and balance.

Then choose discharge, at max rate, to the lowest figure it allows. They will take some time, best watched on a PC. Read off capacity and watch to see if all cells end at the same time or close.

That will give you a 100 percent capacity reading. You can do that 1000 times with these cells right down to 100 percent! So its not harmful.

Then fully charge and balance as normal to 3.600v per cell. You will get exactly the same Ah back in as you took out within .2 of an Ah.