Cyclotricity Stealth 1000W double battery set up

[Madiba]

I am thinking of installing an extra battery on my Cyclotricity Stealth 1000. This means, basically, adding the pannier rack battery (available from Cyclotricity) to the bike using a DPDT switch so you drain one battery first before switching to the other battery. So you have the frame and pannier battery on the bike simultaneously.

Has anyone else tried this, or something similar, successfully?

 

[Deleted member 4366]

I wouldn't use a switch. The power and arcing from the controller's capacitors will damage one. It's much simpler to use a "Y" connector.

 

[Madiba]

Thanks. Is there a technical name for the Y connector and is it available at Maplins? How does it work exactly?

 

[Andy Bluenoes]

Something for me to consider as I may need to increase my mileage from 15 to 20 soon, this may be the simplest option

 

[Deleted member 4366]

Thanks. Is there a technical name for the Y connector and is it available at Maplins? How does it work exactly?

Can you solder?

 

[Madiba]

Can you solder?

No, but please provide instructions as my bike shop are going to do it for me.

 

[Deleted member 4366]

You cut the wire between the battery and the controller. Solder connectors on each side so that you can reconnect it. Then make a small harness with a single connector the same as the battery on one end and two wires soldered to each pole on the connector. Then, solder connectors the same as the controller one to each pair of wires. Now you can join this harness to the controller, which will give two connectors for the batteries. You can plug in both or one at a time, or you can remove it completely and plug in your original battery direct to the controller or the new battery direct to the controller. you can use whatever connectors you want:

https://hobbyking.com/en_us/new-ec5-male-5-set-per-bag.html
https://hobbyking.com/en_us/new-ec5-female-5-set-per-bag.html

 

[Andy Bluenoes]

Sorry to butt in, is there any difference in the way the battery works if you connect them at the same time using the Y connector, or one at a time when the first one has run out?

This could definitely be the answer to my dilemma when i move house

 

[Deleted member 4366]

They have to be at the same voltage if you want to connect them together, and you have to disconnect one before charging.

 

[Andy Bluenoes]

Ok, I would just carry the pair to my office desk and charge them as normal I guess. It might invalidate my warranty I suppose, so propably safer to get a bigger rucksack and stick it in that and swap over when one goes flat

 

[Madiba]

You cut the wire between the battery and the controller. Solder connectors on each side so that you can reconnect it. Then make a small harness with a single connector the same as the battery on one end and two wires soldered to each pole on the connector. Then, solder connectors the same as the controller one to each pair of wires. Now you can join this harness to the controller, which will give two connectors for the batteries. You can plug in both or one at a time, or you can remove it completely and plug in your original battery direct to the controller or the new battery direct to the controller. you can use whatever connectors you want:

https://hobbyking.com/en_us/new-ec5-male-5-set-per-bag.html
https://hobbyking.com/en_us/new-ec5-female-5-set-per-bag.html

Thanks. That's great. I will buy parts for both the switch and Y connector solutions and talk to my bike shop about it - they are very good with electric bikes - before making a final decision. The Y connector does seem the neatest way to do it though.

 

[D8ve]

Sorry to butt in, is there any difference in the way the battery works if you connect them at the same time using the Y connector, or one at a time when the first one has run out?

This could definitely be the answer to my dilemma when i move house

The loading on individual batteries will be lower with the twin setup.
Theoretically you would get longer range and better performance.
Practically I doubt you would see any difference.

 

[Andy Bluenoes]

I spoke with Cyclotricity about this yesterday.

Their advice was that the Y piece would bypass the BMS, so would need something else doing to it......I got a bit lost at the description of what was needed after that.

The other option suggested was a double pole/double pro (i think) switch....

Both would likely invalidate the warranty.

However, in the not too distant future, higher ah batteries may be available from them.....Ill just hold out until then I think.

 

[Nealh]

Sounds like they are talking rubbish.
Each battery has it's own bms so connecting in parallel using a Y lead will make no difference once the bms sees the low voltage it will shut down. Only parallel 2 batteries with the same voltage. Hobby King sell them already made up with various connectors.

 

[Low]

Hi, im doing exactly the same job as you with exactly the same bike, xt90s are the best conectors iv seen on ebay very tough il post the photos of where im up to, the wire im pointing at is where to cut, fyi the batrerys need to be as near as damn it at the same voltage when you hook them up (ref d8v 3 days ago)..
Pic on the way

 

[Low]

 

[Low]

Dont want to highjack your post but.... Does your battery do this after a rain ride?

any idea what the blue is?

 

[Nealh]

XT60's are more then ample for the job and less bulkier in size.

 

[Andy Bluenoes]

Sounds like they are talking rubbish.
Each battery has it's own bms so connecting in parallel using a Y lead will make no difference once the bms sees the low voltage it will shut down. Only parallel 2 batteries with the same voltage. Hobby King sell them already made up with various connectors.

Maybe I didn't explain to them properly what I meant.

So, all you are doing is joining two batteries together with a Y piece? When the first one runs flat, the second kicks in....or they just make one big battery? If you then charge them both to full after each cycle, they should be at the same voltage?

 

[Deleted member 4366]

any idea what the blue is?

It's copper chloride. You've had salt water in there from the winter roads. Salt water is extremely conductive and can cause all sorts of problems. You need to prevent that somehow. It's thrown onto the battery by the front wheel.