Lack of power on FreeGo Martin City

[Sam W]

I'm having trouble with a bike purchased in 2016 and was hoping somebody might be able to help.

The bike lacks power, and assume this is something to do with the battery (shown below). Nominal battery voltage is 36V, and no-load voltage is a bit above this, but I can't easily measure the voltage drop under load. As FreeGo are no longer in existence, I can't just get replacement battery.



What is the best way of sorting this out? Is the best option to get the battery re-celled? Who would people recommend to do this?

I've also thought about getting lower capacity replacement pack of cells, and soldering this in place. I can identify the primary +ve and -ve terminal on the bike (show below), but am less sure about the other wires. Are these just connected to the LCD display to show battery voltage (capacity).



Any help would be appreciated.

Sam

 

[Nealh]

Ebikebatteries.co.uk for a re-cell.

 

[vfr400]

First, you need to determine that the battery is actually faulty. For that, you start by measuring the voltage on its terminals after it's been fully charged and hot off the charger.

 

[Sam W]

Thanks for the replies. I'll have a look at Ebikebatteries.co.uk.

I am reluctant to spend a lot of money on a re-cell to find that it is something else causing the problem. However, I thought that the battery is quite old now, and I was a bit distracted from looking after it by the arrival of a baby, so I can't imagine the battery is in great shape.

Checking the voltage was the first thing that I did and it was a few volts above nominal. I also took the battery to a local company who make batteries for model cars, and they couldn't find any dead cell. I've just tried to check the voltage again, but my multimeter is misbehaving.

 

[vfr400]

Thanks for the replies. I'll have a look at Ebikebatteries.co.uk.

I am reluctant to spend a lot of money on a re-cell to find that it is something else causing the problem. However, I thought that the battery is quite old now, and I was a bit distracted from looking after it by the arrival of a baby, so I can't imagine the battery is in great shape.

Checking the voltage was the first thing that I did and it was a few volts above nominal. I also took the battery to a local company who make batteries for model cars, and they couldn't find any dead cell. I've just tried to check the voltage again, but my multimeter is misbehaving.

Only the actual volts after charging will tell you the battery's health.

 

[Sam W]

I've finally got manged to check the voltage. After a full charge, I am getting 41.5V. The nominal battery voltage is 36V. Does this mean the battery is fine? I'm not sure what else to check, as it's hard to measure the voltage under load.

 

[vfr400]

The next question is about what happens to the voltage when you ride the bike. You have an LCD with a battery indicator. With the battery at 41.5v, it should show full. When you start to ride, what happens on the battery charge indicator, especially when you use high power?

41.5v is not bad, but not necessarily good.

 

[artspeck]

I have this model and it could be nothing more than dirt on either the magnet sensor pickup on the frame or the sensor on the spoke, which may not be aligned up properly.