third party semi integrated battery cases?

[cellsafemode]

I'm going to mod my upcoming lectric xpeak and I'm interested in redoing the integrated battery but with higher capacity (5000mah) and higher quality cells and bms. I'd like to buy the battery enclosure without cells and bms.

I'd get if it's not available yet since the bike hasn't started shipping yet even. but is there a general supply shop people are using for these types of diy batteries that fit in the stock battery openings? or is nobody doing this?

I'd prefer to not have to dissect the stock one since i kind of want to build a second spare without having to pay 500 for another enclosure. but i guess if that's my only option.., it is what it is.

 

[neptronix]

I've never heard of a standardized in-frame battery for anything. Manufacturers of prebuilt ebikes make the shape proprietary so you are forced to buy their batteries.

You'd have to buy the part from them.

 

[amberwolf]

Kinda like printer cartridges...they *could* make them all the same....but then they'd lose the $$ source of selling you theirs.

If the company based their case and frame on an existing design, or if they had someone else make the parts for them, you might find cases out there that are at least close to what you already have, if you're willing to spend the time in google image searches, or just browsing ebay or aliexpress for all the possible battery cases, and then modify what you find to fit (if it's possible).


When looking at higher capacity cells, be sure you are actually getting real ones. Many places will sell you cells that are any capacity you want...on the label.

In reality, they may be garbage cells rewrapped with some custom printed plastic that says whatever they felt like.

Even in real higher capacity cellls, for a given cell volume, often the higher capacity cell is more energy dense (higher Ah) but less power dense (lower Amps capability). So you might get more capacity but at the cost of having to lower the current limit on your controller to not stress the cells, and having less torque and slower accleration and lesser hillclimbing, etc. (and/or greater voltage sag lowering the amount of watts you have available).

 

[cellsafemode]

the 50t cells from, i think, Samsung are like 15amp discharge and 5ah capacity. They're expensive but should be plenty for a sub 30amp setup.

I'm hoping that like most ebike companies in the cheaper range, they are just using the same couple of Chinese manufacturers as everyone else. so sharing components like maybe the battery. since that is expensive and a mass produced part is cheaper than some custom job. but it's also possible they customized some latch and the rest is standard and I'll still be screwed.

was just curious if there was some community site selling parts from these manufacturers in single quantities instead of just big ebike company orders. guess I'll have to wait and see. I'll be fine tearing apart their part if i have to buy it. i just didn't want to wait till feb for spare batteries to ship.

i have a tronic 250 I'm planning on putting in/on and programming coming probably next week so was hoping to start playing with voiding the warranty as soon as i verify everything works with the bike once it arrives.

 

[neptronix]

the 50t cells from, i think, Samsung are like 15amp discharge and 5ah capacity. They're expensive but should be plenty for a sub 30amp setup.

Keep in mind that 15A would be the absolute maximum power a single, isolated cell could tolerate before catching fire. These high energy cells like to be ran at 1C. Even at 1C, at perfect room temperature, they're pretty saggy; you only get 4.8ah out of them in this condition.

You want to overspec the output of a pack full of these cells by a huge amount.

was just curious if there was some community site selling parts from these manufacturers in single quantities instead of just big ebike company orders. guess I'll have to wait and see. I'll be fine tearing apart their part if i have to buy it. i just didn't want to wait till feb for spare batteries to ship.

Never heard of such a thing. Right now the prebuilt ebike scene has way too many players and way too low of quality for anyone to care about starting an 'ebike scrapyard'. Americans generally don't fix things that cost under $2000.

 

[cellsafemode]

Keep in mind that 15A would be the absolute maximum power a single, isolated cell could tolerate before catching fire. These high energy cells like to be ran at 1C. Even at 1C, at perfect room temperature, they're pretty saggy; you only get 4.8ah out of them in this condition.

You want to overspec the output of a pack full of these cells by a huge amount.

View attachment 345097



Never heard of such a thing. Right now the prebuilt ebike scene has way too many players and way too low of quality for anyone to care about starting an 'ebike scrapyard'. Americans generally don't fix things that cost under $2000.

i don't doubt they sag, but the stock batteries are likely lower spec and quality cells and they are sagging during use as well. so all things being equal (stock being less than equal) it would still be a significant improvement to capacity and discharge ability compared to the stock battery.

I'm not interested in really trying to go way beyond stock power... just interested in maxing out range on the internal battery and maybe getting some improved torque by being less current limited for bursts.

 

[neptronix]

Maybe; if they're significantly lower capacity, they could have high output to make up for it and perform better.

The only way to find out is to measure. or open the pack and hope there are markings on the cells.

If you miss the target, it's possible to get worse performance out of your bike and a much lesser improvement than you expected due to sag with a cell swap from a medium power level cell to a very low power, high energy density cell.

 

[neptronix]

Now if you could replace the battery with one that had more cells in parallel, a high energy, wimpy powered cell would work just fine and also give you more power than stock.

Peak power on that bike is 1300w and you have a 14ah battery pack. Peak amps are 24A. An appropriate sized replacement with these high energy cells would be a 25AH battery to achieve a 1C draw, which would correlate with the red line on this graph.



In this scenario where you have 25AH 48v, when you hit the throttle and with the battery at 48v, your pack sags by 2.6v ( 0.2v drop x 13 cells ). This should be similar to your existing pack when new. So if you are going to use this cell, you want more like 30-35ah in order to deliver a little additional power beyond stock.

In simpler terms, the idea you're thinking of is probably going to result in a saggy battery. It would be interesting to know how many cells in series your battery currently has so we can figure out if we can favorably shift the stock battery size upwards without accidentally going backwards in power output.

 

[cellsafemode]

i won't be buying anything until i open it and know for sure. still waiting on that. I'm space limited with an internal battery so without modding for an external parallel connection, I'll probably get more out of overall capacity vs maximum perf. it would be more valuable to me to have longer range at like a 300-500 watt draw vs wot perf.


if i have room to actually add cells, that's a different story. and if this internal option looks un-upgradeable then I'll just go crazy with an external.

 

[cellsafemode]

i imagine it's a 13s4p battery. 3p would require fairly high cost cells to get around 14ah. they charge 500 for these and i bet they make a good profit on that. so I'm thinking 3500mah cells. that would get you 14ah with common cells.

if i can net even 4500mah (cutoff of 3.1v) from these 5000mah cells, that would get me just shy of 30% more range with the same number of cells. if I'm drawing 500 watt, that's about .6C which would put me between the red and pink.

these internal batteries likely have the integrated bms in the pcb that links the cells together leaving no room for a replacement bms . i fully suspect I'm going to be driven extremely angry and frustrated trying to work within the battery compartment and I'll probably end up making this bike ugly with something external.

 

[neptronix]

I'm imagining it's 4p too.

Maybe a 10ah 48v battery in parallel would be a nice balance between ruining the aesthetic, and also increasing the power and range at the same time.

Example of such a pack:
48V 10Ah Bottle Battery



I don't know anything about parallelling BMSed packs and what's involved, other than i know it's possible.

Maybe a nice middle road to go down tho.