Tap your collective knowledge about replacing a battery - 2017 Carrera Vengeance

[KaraWebb]

Hi all,

Apologies if this is a repeat - I did search the forums before posting but only found reference to newer models and was not sure if this was relevant to my case.

My battery, predictably after nearly 4 years of a hard-life, has lost a lot of capacity. I am inclined not to replace my bike as I have, over those years, replaced many of the components and upgraded them during this time (including drive train, front forks, even the hub motor etc.) The bike now rides really well and given the life it will have (thrown on to trains and between 50 miles to 100 miles a week) I don't really want to upgrade etc.

I thought replacing the battery would be straight forward however I cannot find anywhere that has stock of the exact type. I believe it is SF-06 style battery, the motor is a Bafang BFSWX02 36V 250W rear hub motor.

I am relatively handy but inexperienced with e-bikes, I happily upgraded all the bike parts myself and service my car and motorbike myself. I have experience of wiring things like Raspberry Pi's etc. so I am not adverse to a bit of DIY. I thought, before I start stripping bits down, I would ask the advice of those more experienced in this realm than myself!

My questions are:

Can I replace this battery with something (just for example) like this: https://batteryempire.co.uk/batteries-for-ebikes/3169-green-cell-e-bike-battery-36v-13ah-electric-bicycle-li-ion-down-tube-with-charger.html?gclid=CjwKCAiAkan9BRAqEiwAP9X6UfXE9vmuywla1ZSgRhtp2pha36-o8ef4E9heJRK9g54a7pqh8pyQixoCGpkQAvD_BwE - I don't know why but I have a feeling the controller is built in to the battery holder on my bike - again, I could be super wrong about this . . .

If I needed to buy a new battery and controller etc. can anyone recommend any for this motor?

Has anyone found an SF-06 style battery and successfully fitted it to the age and model of bike I have? Links would be massively appreciated.

I don't want to get the battery repacked as the holder on the frame has some damage, I could probably fix this with some plastic weld but really wanted something new, if possible. Thanks in advanced for your advice. happy to provide photos of any parts or pull things apart if that helps!

 

[vfr400]

I'm pretty sure that you can fit any type of 36v battery any way you want. You don't have to fit the same type. Your controller sits in the receiver underneath the battery, so you'd have to relocate it into a small frame bag or similar.

You can confirm that if your battery is only connected to the controller by 2 wires. I'm pretty sure it is. That doesn't apply to the later version with the torque sensor.

 

[KaraWebb]

I'm pretty sure that you can fit any type of 36v battery any way you want. You don't have to fit the same type. Your controller sits in the receiver underneath the battery, so you'd have to relocate it into a small frame bag or similar.

You can confirm that if your battery is only connected to the controller by 2 wires. I'm pretty sure it is. That doesn't apply to the later version with the torque sensor.

that’s what I was hoping to hear . . . I shall have to strip it down this weekend.
As a side note, I used to have NC30 UK VFR400 - I used to love that bike

 

[vfr400]

that’s what I was hoping to hear . . . I shall have to strip it down this weekend.
As a side note, I used to have NC30 UK VFR400 - I used to love that bike

I love all the V4s. They don't seem to be as manic as the straight 4s. I recently gave the NC30 away to a deserving person, now down to just my Deauville, Forza 300 and BSA A10. The BSA will be going shortly too as I haven't done anything with it for 20 years.

 

[KaraWebb]

I’m currently on a kwak er-6 for commuting - not as fun as other bikes but a real workhorse that I cannot kill!

just for reference and for anyone else searching these forums, everything VFR400 said is true when you strip back the plastics! Just need to relocate the controller in a box somewhere and match the rating/fitting

 

[vfr400]

Now you can fit any battery. Some line up with the fixings better than the other.

There are two Hailong cases. One has the fixings very high up, which nearly always means that you have to install a new rivnut, which isn't too difficult. You drill a hole the size of the rivnut body in the frame, drill a 5.5 mm hole in two strips of scrap steel, insert the rivnut in the frame, place the strips over it and screw in the 5mm cap screw while holding the rivnut down. If you're lucky, the rivnut will tighten in the frame and rivet itself in when you tighten the cap screw. sometimes it starts to spin, in which case, with the cap screw in, you drive a wedge between the two strips of steel, which usually pulls the rivnut enough to lock it.

The dolphin cases have much lower fixing points and normally line up. You might have to lengthen a slot with a Dremmel or something.

There are lots of other frame batteries big and small. You have to look at the pictures to see the fixing point arrangement.

It's always a good idea to use three fixings if you can.

Is there any chance of a photo that shows the position of your fixing points better for future reference. Measurements would be useful too or instead.

 

[KaraWebb]

I will pop out again for measurements but here are the arrangements- keep in mind this is a small frame as I’m 5’3 - the old battery plus case for the controller is about 35cm.

 

[vfr400]

that's good. It already has three well-positioned fixing points. If you use a Hailong type, you can drill through the aluminium plate at the bottom for the bottom fixing. It's a bit awkward to mark it for the correct position to drill.

These are the two different plats. You can see that the one on the left is attached to the frame by a cap-screw right in the middle. I have a 6mm rivnut in that position because I ran out of 5mm ones.