Hi

 

Could anyone please recommend an affordable e-bike kit which has a relatively light and portable battery kit that can be easily carried away when the bike is parked at a public location?

 

The existing bike is a locked at a public transit stop often all day. As such I definitely don’t want it to stand out anymore than necessary and don’t want it to scream “e-Bike”.

 

I want to be able to lift the e-Bike battery, pop it in a rucksack and go - without having to carry around an awkwardly sized heavy battery.

 

The Swytch bike kit is the obvious choice but are there any good affordable alternatives? Also, what do people think of that kit quality wise?

 

Thank you

Paul

I would avoid Swytch, expensive and not great reliability

 

The weight and size of the battery is in proportion to its capacity and range, 360Wh batteries around 2.5 kg, 720Wh 3.6 kg

 

What terrain (hilly ?) what weight are you ? What range do you need?

 

If it is going to be left in a place where it can get wet you will need a bike bag to go over it

 

An idea here ?

 

https://www.pedelecs.co.uk/forum/threads/exciting-new-project.49130/post-752456

Edited September 13, 2025Sep 13 by Peter.Bridge

You can use a bag battery with Anderson connector. It is very easy to disconnect and reconnect and does not produce sparks when re-inserted.

 

[mention=6303]Woosh[/mention] is the in frame battery in the Faro easily removable ? Can it only be charged on the bike ?

[mention=6303]Woosh[/mention] is the in frame battery in the Faro easily removable ? Can it only be charged on the bike ?

it is possible to remove the battery but can only realistically be charged on the bike.

Behind the aluminium badge at the front of the bike is a large cutout where you can pull the in-frame battery out. To do that, you have to remove the steerer tube first.

Messy.

 

My home made ali drink bottle 6ah/264wh battery is very removable and takes seconds, approx. weigh it still near 1.5kg but very easy to carry.

When I go to the bank or shop it always comes with me, only last week I popped in to the bank plonking it down on the cabinet at the side of the cash machine, I went to walk out and did a swivel because It clicked I had left it sitting there. The employee near the door helping customers with requests was watching and said ' nearly forgot the drink bottle sir' .

 

Weight/small/size is as Peter has mentioned dependent on ones needs.

Does one have one large battery to cater for longer journeys or two or three smaller ones to cater for short journeys and use as extenders for longer ones.

Other people here have been doing the DIY drink bottle batteries, which inspired me to copy them. WIth the larger 21700 cells, one can do a 10 cell 36V5AH or a 13 cell 48V5AH, with a possible 160 to 200 watt-hours. I find that serviceable for an hour of riding, and I can carry two easily, I didn't mention the 14 cell 52V5AH, also possible, With the right cells, an occasional 15A peak current is reasonable, but small batteries are for small riding,

 

It's hard to find them that small. commercially made, because consumers won't buy something that small, although I suppost that's what you get in the smallest Swytch,

Edited September 14, 2025Sep 14 by harrys

There is some bottle batteries on pswpower but I'm not clear if it includes the mount e.g

 

https://www.pswpower.com/products/electric-bicycle-ebike-battery-hailong-g70-g56-21700-18650-cells-pack-48v-36v-175ah-15ah-20ah-125ah%C2%A0bicycle-lithium-ebike%C2%A0battery%C2%A0lithium-fits1000w-299

There is some bottle batteries on pswpower but I'm not clear if it includes the mount e.g

 

https://www.pswpower.com/products/electric-bicycle-ebike-battery-hailong-g70-g56-21700-18650-cells-pack-48v-36v-175ah-15ah-20ah-125ah%C2%A0bicycle-lithium-ebike%C2%A0battery%C2%A0lithium-fits1000w-299

Packing list:

1 pcs battery pack with BMS

1 pcs 2A charger

1 pcs battery holder

Hi again,

 

First off my apologies for the slow response - and thank you to all of you who took the time to respond.

 

In response to the query from Peter.Bridge about the terrain that the converted e-bike would be used in, the location is in the foot hills of (not very high) mountains. The effect of that is:

1) in one directions, there is a very steep hill where, from one side, the road starts going up and then rises very sharply in a short distance to a crest; on the other side, after the crest, the road falls off in a moderate but longer slope on the other side. Neither is one that an ordinary cyclist would want to tackle as the first is very steep and the second, when going uphill, is just a long stretch rising to the crest;

2) in the other directions, there are also slopes albeit, much more gradual - the sort you don’t notice in a car but definitely do when cycling “uphill” as they just go on and on.

 

In all cases the range is likely to be short on a daily commute, circa 2 miles each way on most days; going to circa 3 miles each way at the weekends. On rare occasions it might need to be as high as circa 7 miles again each way, although that is not a critical case.

 

Hope that helps clarify things,

Paul

Also, just reading the comments on drink bottle batteries, do the posters means they made up the batteries themselves??? If so, how?

Hi again,

 

First off my apologies for the slow response - and thank you to all of you who took the time to respond.

 

In response to the query from Peter.Bridge about the terrain that the converted e-bike would be used in, the location is in the foot hills of (not very high) mountains. The effect of that is:

1) in one directions, there is a very steep hill where, from one side, the road starts going up and then rises very sharply in a short distance to a crest; on the other side, after the crest, the road falls off in a moderate but longer slope on the other side. Neither is one that an ordinary cyclist would want to tackle as the first is very steep and the second, when going uphill, is just a long stretch rising to the crest;

2) in the other directions, there are also slopes albeit, much more gradual - the sort you don’t notice in a car but definitely do when cycling “uphill” as they just go on and on.

 

In all cases the range is likely to be short on a daily commute, circa 2 miles each way on most days; going to circa 3 miles each way at the weekends. On rare occasions it might need to be as high as circa 7 miles again each way, although that is not a critical case.

 

Hope that helps clarify things,

Paul

 

A relatively small battery should suffice 15 miles range including a steep hill.

 

Things to consider :

How heavy are you ?

What motor and controller were you going to use ?

36v or 48v ?

Also, just reading the comments on drink bottle batteries, do the posters means they made up the batteries themselves??? If so, how?

 

Yes.

Small arduino spot welders using a high power R/C lipo battery as a power source for spotting the nickel or copper inter-connectors on.

One also has to solder in a BMS , make allowance for a discharge port and possibly a switch for the BMS.

Was just thinking about your original scenario. I converted a folding bike with a 10Ah battery, which would fit ok in a rucksack. The battery itself weighed 2.7kg

 

It was an easy conversion to do and the bike was quite light and didn't scream ebike

 

 

There is also a 36v 7ah bottle battery here with Samsung cells

 

https://www.pswpower.com/products/electric-bicycle-ebike-downtube-spare-ebike-battery-36v-10ah-bottle-electric-bicycle-battery-pack-fits-350w-bafang-tsdz2b-motor-330

 

 

Edited October 29, 2025Oct 29 by Peter.Bridge

Even with battery powered motor it won't climb hills on its own.

You're gonna have to pedal a lot in low gear up steep hills.

Does it have low gears? Is there a pic of the bike pls?

 

P.s. A mountbike channel on YT made his own "mighty mini" battery of 21700 cells. Was it BermPeak?

Welcome to the forum and Good luck.

 

(P.p.s. Do new members have to wait a certain time period before being allowed to post pics?)

A relatively small battery should suffice 15 miles range including a steep hill.

 

Things to consider :

How heavy are you ?

What motor and controller were you going to use ?

36v or 48v ?

 

Once again, thank you for your reply.

 

The bike I am thinking of converting is my daughter’s who is at uni, so the bike is one of her main modes of transport. She is “normal” for her age if that helps.

 

For the other two questions, I don’t know as the tech details of this are all new to me - and I have no idea why someone might chose 36V over 48V (or vice versa).

 

My initial interest was sparked by the Swytch Air conversion kit with a paperback sized battery that could be easily taken away when the bike was parked at a bike stand beside public transport. Reading online though, people gave it mixed reviews for reliability and I was wondering if there is a better / more reliable system out there.

Was just thinking about your original scenario. I converted a folding bike with a 10Ah battery, which would fit ok in a rucksack. The battery itself weighed 2.7kg

 

It was an easy conversion to do and the bike was quite light and didn't scream ebike

 

[ATTACH type=full" alt="Screenshot_20251028-210557.png]64604[/ATTACH]

 

There is also a 36v 7ah bottle battery here with Samsung cells

 

https://www.pswpower.com/products/electric-bicycle-ebike-downtube-spare-ebike-battery-36v-10ah-bottle-electric-bicycle-battery-pack-fits-350w-bafang-tsdz2b-motor-330

 

 

[ATTACH type=full" alt="Screenshot_20251029-071954.png]64605[/ATTACH][ATTACH type=full" alt="Screenshot_20251029-072030.png]64606[/ATTACH]

That’s (the photo) is along the lines I was hoping for - ie a converted ordinary bike that does the job without screaming “eBike, steal me” when you walk away from it.

Even with battery powered motor it won't climb hills on its own.

You're gonna have to pedal a lot in low gear up steep hills.

Does it have low gears? Is there a pic of the bike pls?

 

P.s. A mountbike channel on YT made his own "mighty mini" battery of 21700 cells. Was it BermPeak?

Welcome to the forum and Good luck.

 

(P.p.s. Do new members have to wait a certain time period before being allowed to post pics?)

 

I understand about the steep hills and needing to pedal.

 

That was one of my other concerns. Ideally, I just want the bike to conform to the legal standards for an e-bike - but that steep hill might require more power than a legal conversion can supply.

 

As for the bike, it is a hybrid bike with lots of gears so that should be fine. The bike is an old Trek Neko - and at this stage the bike locks on it, to stop it being stolen, are worth more than the bike itself!

I understand about the steep hills and needing to pedal.

 

That was one of my other concerns. Ideally, I just want the bike to conform to the legal standards for an e-bike - but that steep hill might require more power than a legal conversion can supply.

 

As for the bike, it is a hybrid bike with lots of gears so that should be fine. The bike is an old Trek Neko - and at this stage the bike locks on it, to stop it being stolen, are worth more than the bike itself!

 

It just depend on how steep is steep, the weight of the rider and slightly the motor choice. A legal 36V 250W system with a 36V 15A controller / 80kg rider & bike combined weight with the rider providing 100W of pedalling power will go up an extended 10% hill at 15km/h or a 15% extended hill at 10km/h. The controller / motor is likely to overheat if you run it at 10 km/h or less for an extended period of time (several minutes) A 100kg rider & bike would go up a 10% hill at 11km/h with 100W pedalling contribution. I believe the Swytch controller can only do maximum 36V 12A so would be less powerful than this.

Was just thinking about your original scenario. I converted a folding bike with a 10Ah battery, which would fit ok in a rucksack. The battery itself weighed 2.7kg

It was an easy conversion to do and the bike was quite light and didn't scream ebike

 

Is the battery box the one on the front steering tube ?

 

I have a battery upgrade planned for my eBrompton, and that large box looks about right for a 10Ahr battery and controller.

 

Where did the box come from ?

I would avoid Swytch, expensive and not great reliability.

 

Also very unreliable for delivery. Look at recent reviews on Trustpilot before you buy (and you won't buy a Swytch).

A majority of the recent reviews are 1*.

Also see https://www.pedelecs.co.uk/forum/threads/swytch-rescue-plan-underway.49231/#post-755076

Is the battery box the one on the front steering tube ?

 

I have a battery upgrade planned for my eBrompton, and that large box looks about right for a 10Ahr battery and controller.

 

Where did the box come from ?

 

The box on the front steering tube is for the controller. The battery is underneath- one of these :

 

https://www.yosepower.co.uk/products/36v10ah-seat-tube-li-ion-e-bike-battery

TVM

 

Price is good.

https://www.yosepower.co.uk/products/e-bike-conversion-kit-36v250w-26-28-rear-cassette-motor-kit-with-36v-bottle-battery-samsung-cell-and-integrated-torque-pas-sensor-model-a3pro

Claims to be a "new" product

Only 3 left! Hehe , 26 or 28in wheel, 252wh, bottle batt, 36v/7ah , torque pas model A3Pro, £382

Apologies if it's already been seen.