Rescue a failing Kalkhoff?

[Kamakiriad]

Of the 15 thin wires, 11 attach by bullet connectors to lugs on the 11 metal plates on the sides. Photo 1 shows one of these wires.



There are 11 plates, six on one side and five on the other.



Four black wires disappear into the bowels of the battery to goodness knows where.



Is that any help, d8veh?

 

[Kamakiriad]

Can anyone help me here? Can I modify the battery to fit the Cyclotricity controller which only has red and black wires for the battery? The Kalkhoff battery has data wires on both output socket and charging socket.
If no reply received soon I will start a new thread in Technical area.

 

[Deleted member 4366]

Measure the 11 voltages on those 11 wires using the cell-pack's main negative as ground. Post them here.

 

[Kamakiriad]

Here we are - using an analogue voltmeter.

 

[Deleted member 4366]

No. I meant measure on the wires at the other end so you know which is which. that's important to get the sequence right when connecting to the new BMS. maybe it would be better if you showed a photo of what you have. You still haven't shown the connectors.

 

[Kamakiriad]

Sorry if I'm being dopey. The voltages are of course the same at the other end of the wires and conveniently they are in order. So from L to R, 0 (black, continuity), 4 (red), 8 (yellow), 12 (green), 16 (orange), 21 (brown), 25 (white), 30 (blue), 34 (purple), 38 (black), 42 (red). Then come the four wires which disappear into the core of the battery and as you say are probably temperature sensors or something. They all have 0 V reading.



The other connector comes from the side charging socket as earlier mentioned.

 

[Deleted member 4366]

You need to measure the voltages on the pins of the 11-way one so that you know the sequence.

 

[Kamakiriad]

Sorry D8veh, now I really am confused. There is no other 11-pin connector and it sounds like I have already done exactly what you are asking me. Can I (politely!) ask you to check through my previous posts and photos? If I am missing something please accept my apologies.

I am happy to send the battery to you and pay you for your time if you are interested.

 

[Deleted member 4366]

Let's take a step back. To fit a new BMS you need a cell-pack positive, a cell-pack negative, a positive charge wire, a negative charge wire and 10 sense wires to tell the BMS the individual cell voltages. Everything else can be chucked. The 10 sense wires have to be arranged in the crrect sequence to connect to the BMS, so you need to know which is B1, B2, B3, .....B10.

Fitting a New BMS will get you a working battery, but there's still two potential problems to do with communication. The controller might not allow power until it's communicated with the battery to confirm that the voltage is correct, and the charger might not charge for the same reason.

First, you need to confirm that your bike will work with a dumb battery. If it does, you can replace the BMS to get going. A charger is about £20.

 

[Kamakiriad]

By a dumb battery I assume you mean I just hook up the main pos and neg terminals and no BMS as if it were a car battery?

If so I will test the motor when it comes back from the shop, hopefully later this week. I had to return it as the wheel rim had a "flat spot".

Kind thanks.

 

[Deleted member 4366]

By a dumb battery I assume you mean I just hook up the main pos and neg terminals and no BMS as if it were a car battery?

If so I will test the motor when it comes back from the shop, hopefully later this week. I had to return it as the wheel rim had a "flat spot".

Kind thanks.

No, I mean one that doesn't communicatewith the controller or charger. You should always use a BMS with a lithium battery.

 

[Kamakiriad]

Okay so I must fit the old BMS back on again. Here is the output socket:



But I don't think I can make my battery "dumb" by simply not connecting the white plug carrying these extra data wires. Back in post #13 I did this:



which is the equivalent and nothing happened. Only 1 volt between red & black. So do I need to cut the four thin black wired referred to in post #26?

Of course these green and yellow wires labelled "from battery" actually originate in the rear hub Kalkhoff motor which had the controller in it.

I've just realised another potential problem:


The Kalkhoff battery has an on/off switch built in to the charge indicator. It runs along the ribbon to the BMS, and the Kalkhoff LCD display wouldn't work unless you pressed this switch first. Could that affect any potential new setup?

 

[Deleted member 4366]

You already confirmed that you have 42v in post #24. All you need to do is connect that to your bike's controller to see if it works. Don't put anything in between. Connect it directly to the output socket for testing.

 

[Kamakiriad]

So can you just clarify, you want me to put the battery back together as it originally was, with the BMS and all the data wires plugged in (first photo, post #32). I don't cut or disconnect any wires. Then I connect the two thick terminals + and - on the output socket directly to the controller?

If so I don't see how that will be any different to what I already did, as there was no circuitry in between battery and controller only the wiring of the battery holder which took the four data wires to dead-ends. I was still getting a 1 volt reading between + and - terminals when the battery is off the bike, and my bike's battery is the same.

I'm sorry if I am misunderstanding you and I regret all the time it is taking for you to reply to me.

 

[Deleted member 4366]

At the moment, your BMS is preventing the battery output, but you have what appears to be a healthy cell-pack. The question is whether any battery can work your bike or whether it needs the communication with the BMS to work.

To test whether any battery will work, all you need to do is connect around 36v to the battery terminals on the bike. An easy way to do it is to wire your cell-pack directly to the battery connector, bypassing the BMS. If that works, then you can replace the BMS with a standard one.

 

[Kamakiriad]

Think I understand now. At the moment the BMS is completely removed. Do I re-fit it and plug all the thin wires back into it apart from the call pack + and - which I connect to the controller instead?

 

[Deleted member 4366]

Not for testing.

 

[Kamakiriad]

So I hook BMS up as in post #36 but don't involve the controller?

 

[Kamakiriad]

Anybody?!

I will understand if D8veh is fed up with my inability to understand his instructions

 

[Deleted member 4366]

I was hoping someone else would chip in. I tried explaining several times in different ways, but you don't seem to be able to get it. All I can suggest is that you read it all again.