Powerful inside-frame battery

Hey-o!

I was just offered a Myatu fatbike for next to nothing, however I was informed the battery had gone bad. I've been scouring the internet for a new one, finding mostly rack- and frame type batteries. I humbly ask for your help to figure out the following:

1. What is this type of battery called?

2. Are there any more powerful ones out there? I.e. at least 48v 15ah, since I plan on putting my 1,5kW motor on there if I decide to buy the bike.

The bike in question looks like this but with slim wheels:

Is it this one?

https://www.globalsources.com/si/AS...34291/pdtl/adult-electric-bike/1167796867.htm

It says 36V 8AH. So 10S4P? Maybe you can contact the seller/manufacturer and find out what it is.

https://www.aliexpress.com/item/329...lgo_pvid=ae18f88b-6615-4161-aefb-a06787adb79b

MTA: in the title it says it is 36V 8AH, but in the description it says 48V 8AH, it might be 13S3P.

RunForTheHills said:

Is it this one?

https://www.globalsources.com/si/AS...34291/pdtl/adult-electric-bike/1167796867.htm

It says 36V 8AH. So 10S4P? Maybe you can contact the seller/manufacturer and find out what it is.

https://www.aliexpress.com/item/329...lgo_pvid=ae18f88b-6615-4161-aefb-a06787adb79b

MTA: in the title it says it is 36V 8AH, but in the description it says 48V 8AH, it might be 13S3P.

Click to expand...

Yes, identical but with fat tires.

Sadly 36v won't do it for me. I need 48v and approx 15ah to supply my beast of a motor (which I plan to replace the stock one with)

Bucket Residence said:

Yes, identical but with fat tires.

Sadly 36v won't do it for me. I need 48v and approx 15ah to supply my beast of a motor (which I plan to replace the stock one with)

Click to expand...

The manufacturer's description is contradictory. It might be a 48V or 36V battery in it. If it is a 10S4P, it would mostly likely be made from 40 18650 cells and if it is a 13S3P, it would probably be made from 36 18650 cells. You would have to open the battery compartment to see how many you might fit in there. I am very new to ebikes, so I don't know much about the other battery chemistries that might be able to be used to meet your requirements like LIPO. For a 1500 watt motor, you will need a 48V battery and controller that can put out north of 30A continuous depending on how you are going to use the bike. Of course you can run the motor on less than 1500 watts.

You might want to pass on this bike and get a frame that can take a bigger battery.

Bucket Residence said:

1. What is this type of battery called?

Click to expand...

Trouble.

2. Are there any more powerful ones out there? I.e. at least 48v 15ah, since I plan on putting my 1,5kW motor on there if I decide to buy the bike.

Click to expand...

You're limited to something close to the number of cells that were in the frame originally. So you can juggle them around for different voltages, e.g. 8S5P, 10S4P, 13S3P, or possibly 14S3P. You're not going to fit a bunch more cells inside.

By spending extra money on it, you might be able to use significantly higher performing cells than what it came with originally. It's very doubtful that you will come up with something that can supply a 1500W motor with what it wants.

You might be able to [cobble] something together from model airplane batteries that can supply plenty of juice, but only for a short duration.

The bike in question looks like this but with slim wheels.

Click to expand...

Hahaha you want to put a 2hp motor on a child's clown bike. Good luck with that. Post videos.

It probably uses the same battery that's in the CeMoto folding bike, like the one I fixed up for Cvin here:
https://endless-sphere.com/forums/viewtopic.php?f=3&t=81629

or the MATE here
https://endless-sphere.com/forums/viewtopic.php?f=3&t=82761

That's a pouch-style battery, using 10 small pouches basically glued together inside a removable aluminum battery box. THere might be 18650-style batteries in the same container shape, too, but the ones in the Cemoto are pouches.

If so, the only way you'll really fit a battery as big as you want on the bike is to either put the whole thing on a rear rack (or panniers, which would ride better) or *maybe* hanging below (or sitting on top of) the main "toptube",

OR

put about 1/2 or maybe only 1/3 of the battery inside the frame, and the rest of it on the rack or toptube.

If you want the same battery, you can buy new ones, but they cost anywhere from $300 to $800, and will still only be 36v and small.


BTW, the controller on that bike is probably inside the frame, too, on the seat-side of the folding joint, and about the size of a pack of cigarettes. Your bigger motor's controller won't fit in there, so you'll have to mount it on the frame somewhere, too.

Bucket Residence said:

I was just offered a Myatu fatbike
<snip>
The bike in question looks like this but with slim wheels:

Click to expand...

Also, these two are incompatible statements. A fatbike doesn't have slim wheels.

So you might want to post a picture of the *actual* bike in question.

Bucket Residence said:

Hey-o!
I was just offered a Myatu fatbike for next to nothing, however I was informed the battery had gone bad. I've been scouring the internet for a new one, finding mostly rack- and frame type batteries. I humbly ask for your help to figure out the following:

Click to expand...

I am not surprised you were offered to have this bike for free Most probably the first owner had the same problem like you have now...find a battery!!!
Many of those eBikes with inframe-batteries are IMO one-way eBikes...

Oh yes, my very unique fat bike with slim tires.

I really appreciate the advice. Another bike with a silver fish battery would perhaps be better, that way I could use the motor to it's full potential. The main reason I'm interested in that particular bike at all is that it's cheap and in good condition apart from the battery.

1000W is more than enough for my needs, I would just need a battery that can supply that or even a little less. I noticed the new Mate X bike (with an identical or at least similar frame) has the option of a 48v 17.5ah battery, so I just assumed one would be available on the market.

I own one of these controllers: https://lunacycle.com/60-amp-36-72v-ebike-bluetooth-programmable-controller/
It's 6x3.5x1.5". As I said I'm still on the fence on whether I should buy the bike or not, but I'd test to see if it fits first.

I managed to find the exact bike:

Iv'e got a little folding bike and was looking for a spare 36v battery. I did see some (listed) at 48v 12a, there may be others:

https://www.aliexpress.com/item/33010445014.html?spm=2114.search0104.3.327.2e5b6c6cQ1LPK5&ws_ab_test=searchweb0_0%2Csearchweb201602_1_10065_10130_10068_10547_319_317_10548_10696_453_10084_454_10083_10618_10307_537_536_10131_10132_10133_10059_10884_10887_321_322_10103%2Csearchweb201603_51%2CppcSwitch_0&algo_expid=80793571-695a-459e-a475-fbaf136cca52-47&algo_pvid=80793571-695a-459e-a475-fbaf136cca52&transAbTest=ae803_4

No idea of the cells (def 18650), but noted, you can also buy the empty boxes.. get someone to build you one with top spec?

There are different lengths so you may be limited there?
Aw's also right, only room for a mini controller, that Luna looks a bit big even? (though you'll get an idea of the size when you pull yours out)

the only controller I know of that would fit in taht space that could run a higher powered system is something like the phaserunner, if it's bolted to the frame so it can use the frame as a heatsink. even the lyen minimonster 6fet wouldn't fit in there unless it's taken out of it's casing, and the heatsink bar bolted directly to the frame.

i expect not all the boxes are the same dimensions, though i've never held any in my hands except the cemoto pack, and it's plastics have basically disintegrated; they're not made very well.

I just had a look at your link and it dropped, in one of the adds i noticed the seller mentions he can use many batteries, including lifpo4.. maybe referring to pouches. I'd thought he meant other battery types rather than filling this box.. Not that it may matter, from what I can gather it looks like a generic box perhaps with two types (in different lengths) (built to fit that sized RHS?). I'd make sure to get the base-plate part as well. Mine is a bit flimsy with a piddly pull out tab, but I do like the concept 'in-frame'.

You may get a broader controller in there if you can minimise the cluster ^(*(%()# wire bundle (if it's like mine).

The inside of your battery would most likely look like mine.
Carefully review my thread on this Ancheer eBike. I posted tons of pictures for reference.

Here is the link : https://endless-sphere.com/forums/viewtopic.php?f=2&t=93576

But I must say... I think a 1.5 kWh motor-controller setup on this is pushing it (weather in 13S 48V or in 10S 36V).
Let's say you opt for 10S4P, and re-cell the battery enclosure with top notch cells than can easily provide 10A all day long (30A rated cells you be your best bet).... Then that's 40A max at 36V so 1440 W... But A BMS rated for that much won't fit in the battery enclosure, most likely. Also your battery won't last many years to say the least. An also, at 40A drain rate, you will probably only get 15 minutes of runtime full-throttle.

For a 1500W setup, I'd recommend a 6P battery to be on the safe side...

The 4P setup would be more comfortable in the 500W zone.
A 3P setup, better stay between 250W and 350W if you're after battery longevity.

Also, keep in mind these eBike were not meant for very high speed...
My Ancheer 20 inch folding ebike is 250W nominal with it's stock 10S4P in-frame battery (36V).
But I solder connector allowing me to quick-disconnect this battery and instead, plug an external 14S4P battery (52V) to overvolt.
Now instead of 28 km/h top speed, I can reach 37 km/h top speed... Trust me, past 35 km/h on this bike, it's starts being sketchy... Not the most stable bike. I'm afraid one day the frame will just snap, so I won't push it unless I'm on really pefectly smooth asphalt pavement in the best possible conditions.

Matador

I agree with the comments above...get an appropriate bike if you want to put more than 250w on it (that includes nothing that folds! )

Well, I found that interesting Matador :lol:
not sure if the op has a new best idea?

I found a seller claiming to offer known, model listed (Pana/Samsung/LG) cells in these battery formats not sure on his 48V stock.. around $400us for 36v/17ah

Matador said:

The inside of your battery would most likely look like mine.
Carefully review my thread on this Ancheer eBike. I posted tons of pictures for reference.

Here is the link : https://endless-sphere.com/forums/viewtopic.php?f=2&t=93576

But I must say... I think a 1.5 kWh motor-controller setup on this is pushing it (weather in 13S 48V or in 10S 36V).
Let's say you opt for 10S4P, and re-cell the battery enclosure with top notch cells than can easily provide 10A all day long (30A rated cells you be your best bet).... Then that's 40A max at 36V so 1440 W... But A BMS rated for that much won't fit in the battery enclosure, most likely. Also your battery won't last many years to say the least. An also, at 40A drain rate, you will probably only get 15 minutes of runtime full-throttle.

For a 1500W setup, I'd recommend a 6P battery to be on the safe side...

The 4P setup would be more comfortable in the 500W zone.
A 3P setup, better stay between 250W and 350W if you're after battery longevity.

Also, keep in mind these eBike were not meant for very high speed...
My Ancheer 20 inch folding ebike is 250W nominal with it's stock 10S4P in-frame battery (36V).
But I solder connector allowing me to quick-disconnect this battery and instead, plug an external 14S4P battery (52V) to overvolt.
Now instead of 28 km/h top speed, I can reach 37 km/h top speed... Trust me, past 35 km/h on this bike, it's starts being sketchy... Not the most stable bike. I'm afraid one day the frame will just snap, so I won't push it unless I'm on really pefectly smooth asphalt pavement in the best possible conditions.

Matador

Click to expand...

Oh n-no. I'm not planning to use all of that power. I tried my brothers 750w bike today and I'm pretty sure that is more than enough. 35-40km/h is also what I aim for (p.s. det ikke lyst men jeg traenger, Matador?), I also need decent torque. I read the whole thread about your project and I'm thoroughly impressed. I want what you have except I don't have the knowledge, skills, tools or space to pull something like that off. How would the battery listed below stack up against your setup? I would of course measure to see if it fits before deciding to buy the bike.

I found a seller on Alibaba offering 48V 14 ah for around 250 USD:
https://www.alibaba.com/product-detail/Rechargeable-48v-battery-folding-electric-bicycle_60858168883.html?spm=a2700.7724857.normalList.89.16277607V1OysA

Bucket Residence said:

Matador said:

The inside of your battery would most likely look like mine.
Carefully review my thread on this Ancheer eBike. I posted tons of pictures for reference.

Here is the link : https://endless-sphere.com/forums/viewtopic.php?f=2&t=93576

But I must say... I think a 1.5 kWh motor-controller setup on this is pushing it (weather in 13S 48V or in 10S 36V).
Let's say you opt for 10S4P, and re-cell the battery enclosure with top notch cells than can easily provide 10A all day long (30A rated cells you be your best bet).... Then that's 40A max at 36V so 1440 W... But A BMS rated for that much won't fit in the battery enclosure, most likely. Also your battery won't last many years to say the least. An also, at 40A drain rate, you will probably only get 15 minutes of runtime full-throttle.

For a 1500W setup, I'd recommend a 6P battery to be on the safe side...

The 4P setup would be more comfortable in the 500W zone.
A 3P setup, better stay between 250W and 350W if you're after battery longevity.

Also, keep in mind these eBike were not meant for very high speed...
My Ancheer 20 inch folding ebike is 250W nominal with it's stock 10S4P in-frame battery (36V).
But I solder connector allowing me to quick-disconnect this battery and instead, plug an external 14S4P battery (52V) to overvolt.
Now instead of 28 km/h top speed, I can reach 37 km/h top speed... Trust me, past 35 km/h on this bike, it's starts being sketchy... Not the most stable bike. I'm afraid one day the frame will just snap, so I won't push it unless I'm on really pefectly smooth asphalt pavement in the best possible conditions.

Matador

Click to expand...

Oh n-no. I'm not planning to use all of that power. I tried my brothers 750w bike today and I'm pretty sure that is more than enough. 35-40km/h is also what I aim for (p.s. det ikke lyst men jeg traenger, Matador?), I also need decent torque. I read the whole thread about your project and I'm thoroughly impressed. I want what you have except I don't have the knowledge, skills, tools or space to pull something like that off. How would the battery listed below stack up against your setup? I would of course measure to see if it fits before deciding to buy the bike.

I found a seller on Alibaba offering 48V 14 ah for around 250 USD:
https://www.alibaba.com/product-detail/Rechargeable-48v-battery-folding-electric-bicycle_60858168883.html?spm=a2700.7724857.normalList.89.16277607V1OysA

Click to expand...

Glad you enjoyed my thread on the Ancheer 20 inch folding 250W ebike and how to overclock/overvolt it.

That battery I built doesn't fit in the original frame tube... I use it as a spare backpack battery, but you can also put it in a rear rack... The bike I have looked cool, but honestly, even folded it doesn't really save up that much more space . Beside (pseudo) commodity of folding, I think I would rather buy a more rigid frame instead now that I look back .... It's just much more comfortable and stable to have a non-foldable frame AND larger wheels IMO. I would put a 1.5kW setup on a suspension bike with strudy components (I actually also have a bike with a BBSHD, a hybrid which reached 55-60 km/h, with 700 wheels), but with that 20inch wheel folding bike, no way i'd go that far as to pump it up to 1500W (Warning torque arms needed!). My setup was 36V 250W stock...

I overvolted from 10S to 14S battery and now, the 250W setup produces 350W (continuous mechanical output). The beauty of it is that geared hub motor can reliably and easily pushed to even 500W. The other cool thing is I kept the same controller (just upped the voltage while max amperage rating stayed the same). With the 52V (14S) battery, I now reach 37 km/h top speed (clocked on GPS) instead of 27-28 km/h. Acceleration is the same though (plenty good since smaller 20 inch wheels give you more torque than typical 26 inch on the same setup). I thought about swapping for a controller that can handle more current, but they are bigger (aka, don't fit in frame tube), and would require modding to adapt to my wiring harnest (I had to map my wiring harnest to understand all of it) as you can see from my post.

So honestly, if you want power that you say you probably use it go for it. But I would'nt go past 500W on this folding frame as it would probably difficult to use. Even me with my 350W setup, I find it's tricky to go to mid-range speeds. My twist throttle tends to be low resolution, acting more like an on-off switch than a gradual throttle... SO I find myself using thoggleing through LOW-MID-HIGH settings of the Controller display quite often when I want to ride more casual... 37 km/h is quick and usefull on smooth asphalt of some long, straight and non-busy bike lanes... But in the city streets, I typically just want to top out at 32 km/h...

If you go the overclock root. I feel a 12S battery to me would be the sweet spot for the Ancheer 20 inch folding bike in terms of speed... 14S is a bit overkill... But I have to admit the stock 10S battery can feel a buit slow at times maxing out at 27-28 km/h...
Make sure to change your chainring to a bigger one too !

Matador