24V battery on Panasonic 26V

[flecc]

Traceour's pic only shows three pins , I would unscrew the top and investigate if all three are wired and or what the third may connect to or do if connected.

All three are always connected on these units:



The centre wire goes through the loom into a motor unit connector on the circuit board and this is encapsulated and sealed into the crankcase half, so no access for tracing.
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[SHA222]

Hey!

Just got an Helkama Cargo Bike, not sure the model..
Asuming its 26V. Panasonic motor.
The OEM battery are a fortune and I wonder how the bike will run on 24V?
Could it work? If so, I build my own battery and 3D print a new case

There are reasonably priced 26v batteries in Germany. I have used these for several years without any problems. The original charger works with these.

E-Bike Fahrrad Akku für Panasonic Flyer S Tour 26" S Tour 28" 15,6Ah 26V | eBay

 

[traceour]

Thanks guys for so much info, took some photos today, the display has an 36V label underneath!?
The drive unit has a label of:
Num082
WKS-8
Thin wire in the second pin

 

[flecc]

Hey!

Just got an Helkama Cargo Bike, not sure the model..
Asuming its 26V. Panasonic motor.

Are you sure this is a working bike since it is an old model? I'd hate to see you spend on a new battery only to find the motor is dud. Panasonic dont supply any spares, repair is by replacement of the whole unit usually costing well over £500.
.

 

[traceour]

Are you sure this is a working bike since it is an old model? I'd hate to see you spend on a new battery only to find the motor is dud. Panasonic dont supply any spares, repair is by replacement of the whole unit usually costing well over £500.
.

Not sure, thus I like to test it first on the bench before I buy a battery. Now I'm unsure what voltage it is

 

[guerney]

Not for the flyer but... while looking for ebikes on Vinted a couple of months ago, I spied this - I don't know if it's of any use to Panasonic man, beast or thing, but it's still there for £100. If suitable for someone who ends up finding this thread on Google, read Vinted's payment protection small print, and make an absurd lowball offer?

https://www.vinted.co.uk/items/4432966614-panasonic-kalkoff-l-ion-ebike-battery?referrer=catalog

Whoa here's another one:

https://www.vinted.co.uk/items/4433150864-panasonic-ebike-battery?referrer=catalog

£241.15 "Watt Boston", whatever that is, no charger:

https://www.vinted.co.uk/items/4748805688-watt-boston-male-2023-250-watt-36v-black-ebike?referrer=catalog

£315 slightly faulty Mirider:

https://www.vinted.co.uk/items/4290536432-ebike-legal-pedal-assist?referrer=catalog

£1050 Hai! Bike with "Expensive upgrades":

https://www.vinted.co.uk/items/4722944135-haibike-ebike?referrer=catalog

Rare and odd electricals turn up on Vinted. No listing fees, unlike ebay.

 

[flecc]

Not sure, thus I like to test it first on the bench before I buy a battery. Now I'm unsure what voltage it is

If the handlebar head unit is labelled 36 volt as you've found, the whole system probably is. The 15/6/29 on the motor may indicate the date made in 2015, the 36 volt units were being sold then. Maybe try asking Helkama for information?
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[SHA222]

Not sure, thus I like to test it first on the bench before I buy a battery. Now I'm unsure what voltage it is

Bench testing these motors will be difficult because when you apply voltage the motor will not rotate. It is a pedelec system and you have to apply a force to the pedal to rotate the motor and it will be difficult to gauge the motor response.
I am not sure but you may be able to use the pedal assist plug for this.( I think one of the 2 spare plugs in the loom is intended for the walk assist function). You need to identify the 2 relevant wires and link these via a resister to simulate the walk assist button.

Panasonic do not publish their wiring diagrams but you will find some useful wiring details and error codes in the following handbook.
Panasonic Mittelmotor Technisches Handbuch (yumpu.com)

 

[saneagle]

Not sure, thus I like to test it first on the bench before I buy a battery. Now I'm unsure what voltage it is

7S lithium. Anywhere between 21v and 29v.4v will work it, provided that you put the right signal on the third wire.

 

[traceour]

Send the pictures to my local Helkama dealer, he thought it was 36V. Now i will try to hook up a battery to test. If not working I have to investigate what the 3rd pin does

 

[saneagle]

Send the pictures to my local Helkama dealer, he thought it was 36V. Now i will try to hook up a battery to test. If not working I have to investigate what the 3rd pin does

It's been a long time since I dealt with one of those motors, but I have something at the back of my mind that says that the third wire something to do with the battery level display. Presumably, if the control panel can't get an idea of the battery voltage, it won't allow power. I might be completely wrong about that wire, though, so be careful.

 

[traceour]

Well, hooked up 36V to the bike, battery bar flashing, no other life. Tempting to put 36V to the 3rd pin, grey wire. But assuming it not that easy!?

 

[SHA222]

Well, hooked up 36V to the bike, battery bar flashing, no other life. Tempting to put 36V to the 3rd pin, grey wire. But assuming it not that easy!?

It is a pedelec. The motor will not rotate and therefore you will not see it working unless you pedal. Does it feel easier to rotate with the power on?
Alternative may be to simulate walk assist function by connecting the 2 wires with a resister in the walk assist plug. I have not done this and therefore not sure.
In the 26v batteries the grey wire has the same voltage as the main wire. It bypasses the fuse in the battery I assume to power the display and show error messages if the main system fails. Assume 36v will be the same.