February 2, 20179 yr 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?
February 2, 20179 yr 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.
February 3, 20179 yr Author Thanks. Is there a technical name for the Y connector and is it available at Maplins? How does it work exactly?
February 3, 20179 yr Something for me to consider as I may need to increase my mileage from 15 to 20 soon, this may be the simplest option
February 3, 20179 yr Thanks. Is there a technical name for the Y connector and is it available at Maplins? How does it work exactly? Can you solder?
February 4, 20179 yr Author Can you solder? No, but please provide instructions as my bike shop are going to do it for me.
February 4, 20179 yr 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
February 4, 20179 yr 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
February 4, 20179 yr They have to be at the same voltage if you want to connect them together, and you have to disconnect one before charging.
February 4, 20179 yr 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
February 5, 20179 yr Author 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.
February 6, 20179 yr 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.
February 7, 20179 yr 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.
February 7, 20179 yr 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.
February 7, 20179 yr 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
February 7, 20179 yr Dont want to highjack your post but.... Does your battery do this after a rain ride? any idea what the blue is?
February 7, 20179 yr 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?
February 8, 20179 yr 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.
February 8, 20179 yr 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? In parallel you get one larger ah battery at the same voltage, in use they should both decrease in voltage at a similar rate and within 0.01-0.03v of each other (all cells being equal). If one battery for any reason shuts down the other will still work. Charging after use as you say the voltage should be the same occasionally worth checking though as it only takes 2 secs to test. But remember charge each battery independent of the other disconnected from the Y lead. I use lipo with out bms and will connect either 6.6ah or 5.2ah packs together 3,4 or 6 at a time to have a larger discharging pack all connected using parallel triple/double Y leads for the most part they stay within 0.3v of each other and only balance them if they are over 0.05v out. Edited February 8, 20179 yr by Nealh
February 8, 20179 yr I use lipo with out bms and will connect either 6.6ah or 5.2ah packs together 3,4 or 6 at a time to have a larger discharging pack all connected using parallel triple/double Y leads for the most part they stay within 0.3v of each other and only balance them if they are over 0.05v out. I'm just curious Nealh , do you use lipo's regularly or as your main battery power ?
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