100+ Miles of Fun per Charge: 5.1kWh batt, 20kw capable

Using Toshibas 3.6mOhms on this controller. With 24Fets, not so much heat is generated in the first place. But when it is, two row designs, thick heat spreader, and shell help.
There is also a fan under the seat post, so it can force the air through the frame box if it will ever become necessary. Hard to tell now with subzero temperature outside. I guess summer will tell.

fechter said:

Hopefully you can fit the controller flat against a panel so it gets some heat dissipation. If the side panels are aluminum then almost anywhere would be good but obviously in front is better.

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Right about the sub-freezing temps. Too cold and rainy to even ride lately. A fan inside the compartment will probably work well when the weather warms up.

First- awesome build and this basically gave me all the evidence I needed to pull the trigger on building my bike. I have a question about the battery though.

Did you add anything to the bottom of the frame to reinforce it and/or create a flatter platform for the batteries to sit on? Or is the pack rigidity good enough for them to sit on top?

I have my frame now, and the bottom is not flat, as the steel frame has the plastic part on the outside, though it would be easy enough to install a steel sheet on the bottom. I am aiming to fit about 80 more cells than you have in yours, for 20s28p, and I have yet to receive any batteries so I have no clue if I can fit them, it is probably a pipe dream but batteries are useful for all sorts of things.
Thanks

My 5kWh/20kw pack didn't need added rigidity at the bottom because it was shaped to go around the semicircle at the bottom of the frame distributing the pack weight evenly. I only had a bit of thin padding in that area.

With a completely square/rectangular pack shapes, I am adding epoxied fiber-glass to protect the cells from impact from the semicircle BB part of the frame. My latest battery design also use very strong brackets that can't be split easily with a hammer. One thing you need to make sure there is a good electrical and mechanical separation between the two bricks places alongside in the frame to prevent from shorts between two big halves of the pack.

ninepointeight said:

First- awesome build and this basically gave me all the evidence I needed to pull the trigger on building my bike. I have a question about the battery though.

Did you add anything to the bottom of the frame to reinforce it and/or create a flatter platform for the batteries to sit on? Or is the pack rigidity good enough for them to sit on top?

I have my frame now, and the bottom is not flat, as the steel frame has the plastic part on the outside, though it would be easy enough to install a steel sheet on the bottom. I am aiming to fit about 80 more cells than you have in yours, for 20s28p, and I have yet to receive any batteries so I have no clue if I can fit them, it is probably a pipe dream but batteries are useful for all sorts of things.
Thanks

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I sit right at the other end of this build, I run a 26s3P pack with around 600whrs , i go out for quick 20 min rides with 5kw peaks, I'm usually ready for a rest when the pack runs out It also gets me my 30klm to work if needed. Having a light bike off road is nice but a nice heavy long range bike is better. A light bike means you really feel the bumps, even with 200mm travel even with very soft setup. Heavy bikes mean less stiction on the forks offering supper smooth rides. I bet this build soaks up the bumps and makes for easy long rides edging in on light motorcross. Will be interesting to see what range u get.

Powervelocity.com said:

My 5kWh/20kw pack didn't need added rigidity at the bottom because it was shaped to go around the semicircle at the bottom of the frame distributing the pack weight evenly. I only had a bit of thin padding in that area.

With a completely square/rectangular pack shapes, I am adding epoxied fiber-glass to protect the cells from impact from the semicircle BB part of the frame. My latest battery design also use very strong brackets that can't be split easily with a hammer. One thing you need to make sure there is a good electrical and mechanical separation between the two bricks places alongside in the frame to prevent from shorts between two big halves of the pack.

ninepointeight said:

First- awesome build and this basically gave me all the evidence I needed to pull the trigger on building my bike. I have a question about the battery though.

Did you add anything to the bottom of the frame to reinforce it and/or create a flatter platform for the batteries to sit on? Or is the pack rigidity good enough for them to sit on top?

I have my frame now, and the bottom is not flat, as the steel frame has the plastic part on the outside, though it would be easy enough to install a steel sheet on the bottom. I am aiming to fit about 80 more cells than you have in yours, for 20s28p, and I have yet to receive any batteries so I have no clue if I can fit them, it is probably a pipe dream but batteries are useful for all sorts of things.
Thanks

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Excellent idea with the epoxied fiber-glass around that area, but did you use that throughout the whole pack, between the individual cells? If you don't mind sharing, I am curious about what you use to hold the whole pack together, hot glue? Or something tougher?

Thanks

No need to use it throughout the whole pack, that adds unnecessary volume and weight. Hot glue is too much mess as well. I have had good success using double sided tape.

ninepointeight said:

Excellent idea with the epoxied fiber-glass around that area, but did you use that throughout the whole pack, between the individual cells? If you don't mind sharing, I am curious about what you use to hold the whole pack together, hot glue? Or something tougher?

Thanks

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Powervelocity.com said:

No need to use it throughout the whole pack, that adds unnecessary volume and weight. Hot glue is too much mess as well. I have had good success using double sided tape.

ninepointeight said:

Excellent idea with the epoxied fiber-glass around that area, but did you use that throughout the whole pack, between the individual cells? If you don't mind sharing, I am curious about what you use to hold the whole pack together, hot glue? Or something tougher?

Thanks

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Double sided tape, any details on brand? I used hot glue for my pack and while messy and did a fairly good job, but its not fool proof, hotglue doesn't always stick as well as you think. Ive had thoughts about a full epoxy bath at the end after a good test of the cells and a few cycles under the belt. it would add weight but a totally water proof solid pack! Grin was doing this with their small packs.

Jestronix said:

Double sided tape, any details on brand? I used hot glue for my pack and while messy and did a fairly good job, but its not fool proof, hotglue doesn't always stick as well as you think. Ive had thoughts about a full epoxy bath at the end after a good test of the cells and a few cycles under the belt. it would add weight but a totally water proof solid pack! Grin was doing this with their small packs.

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While that is great for small packs, like powervelocity said, it is heavy. One of the main advantages in my mind of using hot glue over other glues and resins is being able to take the pack apart if need be to fix or replace cells. I read somewhere on here of a certain solvent that weakens/dissolves hot glue. Also, I have found proper tab welding will hold a many many cells together with nothing else, but you still have chaffing which will be a problem between series groups.

This works well. Easy to assemble and easy to disassemble.No chafing. Quick to install and no glue mess.

Powervelocity.com said:

Here is what it looks like so far. Some highlights/features:

- Newly designed 3.36kw battery pack: top voltage raised to 109v (26s). Potentially higher top speeds (above 60 mph);
- Estimated range at 40 mph flat: 70 miles;
- 10kw of rated continuous output, 15kw peak;
- Controller is beefier inside out: 24Fets, low RDS, two row design, thicker shell, lots of capacitance for hard acceleration;
- Onboard fast charger (estimated empty to full in 1.5 hour at 120v or 1 hour at 240v);
- All components are inside (the old controller on the downtube is going away);
- BMS and Controller are programmable wirelessly from a phone;
- Four temperature probes inside the frame box (can be used to monitor controller, BMS, battery).

Still need to finish some wiring and do the field tests.

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Any updates on this higher voltage build?

We have been building 26s packs (109v HVC) recently. 3.3kwh capacity, 10kw peak output. Smart BMS with wireless monitoring functionality as an option.

They fit perfectly in pretty much all bomber style frames and have the best balance for power, size and price. Will post some pictures.

st35326 said:

Powervelocity.com said:

Here is what it looks like so far. Some highlights/features:

- Newly designed 3.36kw battery pack: top voltage raised to 109v (26s). Potentially higher top speeds (above 60 mph);
- Estimated range at 40 mph flat: 70 miles;
- 10kw of rated continuous output, 15kw peak;
- Controller is beefier inside out: 24Fets, low RDS, two row design, thicker shell, lots of capacitance for hard acceleration;
- Onboard fast charger (estimated empty to full in 1.5 hour at 120v or 1 hour at 240v);
- All components are inside (the old controller on the downtube is going away);
- BMS and Controller are programmable wirelessly from a phone;
- Four temperature probes inside the frame box (can be used to monitor controller, BMS, battery).

Still need to finish some wiring and do the field tests.

Click to expand...

Any updates on this higher voltage build?

Click to expand...

Powervelocity.com said:

We have been building 26s packs (109v HVC) recently. 3.3kwh capacity, 10kw peak output. Smart BMS with wireless monitoring functionality as an option.

They fit perfectly in pretty much all bomber style frames and have the best balance for power, size and price. Will post some pictures.

st35326 said:

Powervelocity.com said:

Here is what it looks like so far. Some highlights/features:

- Newly designed 3.36kw battery pack: top voltage raised to 109v (26s). Potentially higher top speeds (above 60 mph);
- Estimated range at 40 mph flat: 70 miles;
- 10kw of rated continuous output, 15kw peak;
- Controller is beefier inside out: 24Fets, low RDS, two row design, thicker shell, lots of capacitance for hard acceleration;
- Onboard fast charger (estimated empty to full in 1.5 hour at 120v or 1 hour at 240v);
- All components are inside (the old controller on the downtube is going away);
- BMS and Controller are programmable wirelessly from a phone;
- Four temperature probes inside the frame box (can be used to monitor controller, BMS, battery).

Still need to finish some wiring and do the field tests.

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Any updates on this higher voltage build?

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Ive got two Bombers, but I have grown accustom to the B-52 acceleration. I actually reached out to the guy who makes the Defkon 1 bike but it basically came down to the addition of a moto rim would put me back to Bomber acceleration level. Speed is an absolute addiction.

awesome stuff!
iv done something similar with a nyx frame, 22s18p30Qpack, max-e 14kw, qs205 w/6wag upgraded phases.
i had the controller internal, with similar 12p pack,and used fan in seatpost to remove controller heat, but after upsizing the pack, only the dc/dc, charger coil, and bms fit in with the cells, i ditched the fan and put the controller out in the wind.
the fan was very effective when i had it though.

w/ regards to pack support in frame, iv decided to hotglue it in once its past the mockup stage, w/good quality hotglue(bosch brand)
since i discovered that metholated spirit will very effectively remove hotglue, im not scared to spread it about in the frame

i also love the shinko 241s and have a pair, but not sure if i should use them over the slicker tyres i have due to decrease in efficiency, as tradeoff for the absolutely awesome traction they will have. any info on this?

i currently use a hydenau M3, 2,1/4"/19" on the front. looks like your front tyre there. iv been so impressed w/this tyre so far, really silent/efficient but had heaps of grip.
i have a eltek flatpack s on my wishlist :lol:

I must admit im now very interested in your 24fet controller as adapttos are too expensive, tend to fail and are too expensive to repair.
the only features id really miss are the battery cell monitor screen and the charging through controller w/coil, but i could live without these, id rather something powerful and simple/silent compact that is more reliable.

cheers,
RTL

Thanks for the feedback.
I have looked into the idea of charging through controller and it can be done, however, I can't justify investing time into this just yet. With Elteks, you can now program your needed voltage right on the charger and no need to deal with dangling coils.

I have also downsized on the battery pack front, went to 3.3kwh, to be able to fit everything inside of the frame but also increased the voltage to 109v (26s) for higher speed and efficiency. It does 50 miles of normal riding (30-40 mph) and 40 miles running 45-60 mph per charge. No really need in longer range and, thus, no need to carry exra battery weight.

Here is what my bike looks like nowadays.





Gotta check out some slick tires like Hedenau. 241s worked well but make some noise on a paved road.

ridethelightning said:

awesome stuff!
iv done something similar with a nyx frame, 22s18p30Qpack, max-e 14kw, qs205 w/6wag upgraded phases.
i had the controller internal, with similar 12p pack,and used fan in seatpost to remove controller heat, but after upsizing the pack, only the dc/dc, charger coil, and bms fit in with the cells, i ditched the fan and put the controller out in the wind.
the fan was very effective when i had it though.

w/ regards to pack support in frame, iv decided to hotglue it in once its past the mockup stage, w/good quality hotglue(bosch brand)
since i discovered that metholated spirit will very effectively remove hotglue, im not scared to spread it about in the frame

i also love the shinko 241s and have a pair, but not sure if i should use them over the slicker tyres i have due to decrease in efficiency, as tradeoff for the absolutely awesome traction they will have. any info on this?

i currently use a hydenau M3, 2,1/4"/19" on the front. looks like your front tyre there. iv been so impressed w/this tyre so far, really silent/efficient but had heaps of grip.
i have a eltek flatpack s on my wishlist :lol:

I must admit im now very interested in your 24fet controller as adapttos are too expensive, tend to fail and are too expensive to repair.
the only features id really miss are the battery cell monitor screen and the charging through controller w/coil, but i could live without these, id rather something powerful and simple/silent compact that is more reliable.

cheers,
RTL

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Which bms with smart monitoring do you have?

Can you give me a price on your new battery packs and how much you would charge for when you're high power controllers

In your most recent photo are you using the Black Bolts or Custom bolts for the side cover? just noticed the difference and had thought about the concept myself. awesome Thread btw

Yes, 6M automotive bolts work great. They are steel - not as flimsy as the stock aluminum ones.

Suspekt1 said:

In your most recent photo are you using the Black Bolts or Custom bolts for the side cover? just noticed the difference and had thought about the concept myself. awesome Thread btw

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Powervelocity.com said:

Yes, 6M automotive bolts work great. They are steel - not as flimsy as the stock aluminum ones.

Suspekt1 said:

In your most recent photo are you using the Black Bolts or Custom bolts for the side cover? just noticed the difference and had thought about the concept myself. awesome Thread btw

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Could you elaborate? I am not familiar with the naming conventions of bolts, did you order them online, and if so could you link? Googling turns up many different bolts of various dimensions. I am looking for some bolts to replace the originals as well, but would prefer them to be longer than the originals.
Cheers

They are called Automotive Screws 6mm x 25mm made by Midwest Fasteners. Yes, and they are longer than original ones.
Interestingly, I can't find these exactly ones online but I could find them at my local garden supplies store.

Here is very similar one:
https://www.kimballmidwest.com/All-Products/Fleet-and-Vehicle-Maintenance/Automotive-Clips-and-Fasteners/Body-Bolts/131180/

I’ve been told it’s impossible to charge two battery packs of 18650 cells side-by-side as you did by folks at EM3EV, Electric Rider and other EV shops. Perhaps it was a liability thing. But seeing your build makes me believe it’s possible to charge two batteries with one charger.
So, to break it down you have 2x 12S20P packs that equal to approx 44V 58Ah, brought together in series. (Sorry I’m spelling it out, but it makes it easier to digest and perhaps helps others following)
I’d like to build a pack similar using 20S14P. To do that I see I must split the pack side-by-side into 2x 36V 42Ah battery packs. To make it fit along with the on-board charger and other accessories I’d like.
Which charger would you recommend charging both batteries using one charger? I already have 2 Veribest 4A chargers for my current 20S6P from Electric Rider. I’d like to keep one at home and maybe one on-board the EEB.
If the charging time takes too long I know I can always go up to an 8A charger which will decrease the life cycles of the battery pack.
In addition, could I install one BMS such as the Adappto to monitor both packs. Or will each pack need their own BMS?

I cringe when I hear "never", "always" or "impossible". Always is never always and nothing is impossible, it's all about how much effort and time you want to put into making it possible.

I think of this battery as a single pack rather than two connected together. If you have 2, 3 or more packs with exactly the same cells and the number of cells in a series is the same, you can connect them together in series indefinitely, not just 2 packs but 100 or 1000 packs. Then you make sure the voltages across all cells are balanced and that where a BMS is handy. If you follow these two simple requirements, your battery pack will be fine. For parallel connection, you don't even need to have the same cells or capacities, those can be different. All you need is to make sure they all operate within the same voltage range and the voltage is the same when you connect them together.

My guess is that the packs you were asking about with those vendors do not have sufficient side protection to put them alongside and protect from rubbing through the shrink wrap. If it rubs through, you will have a short that can turn into a firey and expensive show. I make sure that I use very strong dielectric between the bricks. PCB material works best for this.

Regarding charges, it doesn't matter what you use as long as it outputs correct voltage and amps are lower than cells can take. A 24s20p pack with Panasonic PFs or GAs will need a 100.8v charger and can take up to 32A of charge current (1.6A per cell with no cooling). With cooling, you can supercharge this pack at 40A or possibly above. So, in short, your 4A or 8A will work just fine but will take many hours to charge the pack from empty.

Regarding BMS, it best to go with a single BMS to make sure all cells across the whole pack are balanced in sync. If you go with two BMSes, you will have to periodically check and make sure the voltage is balanced between the packs that have separate BMSes.

Since building this pack, I have made a lot of improvements in the pack design and safety. I am now building 26s10p packs (same two bricks along side) with 3.5Ah cells, which makes it 3.3kwh of total capacity. This is very close to your target (24s 88v X 42A = 3.6kwh). Top voltage increased to 109v now allows higher speeds and better efficiencies charging and discharging the pack. Most importantly, I've added safety features like making sure no cells are touching each other but still keeping them close in hexagonal pattern to ensure small size of the pack. That helps with thermal management as well.

Here is some details on the specs:
https://endless-sphere.com/forums/viewtopic.php?f=31&t=89020

CLIFFSIDE said:

I’ve been told it’s impossible to charge two battery packs of 18650 cells side-by-side as you did by folks at EM3EV, Electric Rider and other EV shops. Perhaps it was a liability thing. But seeing your build makes me believe it’s possible to charge two batteries with one charger.
So, to break it down you have 2x 12S20P packs that equal to approx 44V 58Ah, brought together in series. (Sorry I’m spelling it out, but it makes it easier to digest and perhaps helps others following)
I’d like to build a pack similar using 20S14P. To do that I see I must split the pack side-by-side into 2x 36V 42Ah battery packs. To make it fit along with the on-board charger and other accessories I’d like.
Which charger would you recommend charging both batteries using one charger? I already have 2 Veribest 4A chargers for my current 20S6P from Electric Rider. I’d like to keep one at home and maybe one on-board the EEB.
If the charging time takes too long I know I can always go up to an 8A charger which will decrease the life cycles of the battery pack.
In addition, could I install one BMS such as the Adappto to monitor both packs. Or will each pack need their own BMS?

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Thanks for the quick reply! This seems like a daunting task as a first build, but at the same time looks to be a fun experience. However I'll keep powervelocity.com in mind in case I case i decide to go for professional build quality. I'll send you a PM on more specifically the specs i would like.

All the scientific evidence aside, think about this: there must be a reason why EVs beyond bikes run higher voltages. Not 48 or 72 but 200-400V.

Whether discouragement needs to be followed is more of a philosophical question and a person's position in life.

I hear you on the safety margin. I now use components in controllers that rated over what I recommend to run them at. For example, 120v units are recommended to be run up to 110v and 150v version up to 140v.

John in CR said:

Of course there's a performance advantage using higher voltage, which is a different topic. The point I was making is that for a given rpm and torque a given motor gets the same signal from a controller regardless of pack voltage. It may be broken up into different size pulses due to pwm, but what the motor "sees" is a relatively constant supply. That means we don't get a benefit in the form of reduced I2R losses by using higher voltage for the same power. Yes, power input is volts X amps, but volts and amps have to be looked at separately...current for torque (acceleration/thrust) and voltage for rpm (speed, though there's a torque component with speed since the load of overcoming wind resistance increases geometrically.)

Regarding promoting the use of 100V limit equipment with packs that are 100V fresh off the charge, regardless of anecdotal evidence of people getting away with it, it should be discouraged. Those who get away with it are pushing light loads and use easy to drive motors, but even then failures are too common, and no one pushing real performance has gotten away with it without popping plenty of controllers. Since you're a vendor I'm trying to do you a favor. We've had only one vendor on ES who promoted the use of 24s packs with 100V limit components in the controllers, and he quickly went out of business. Absolute reliability is pretty easy even at extreme performance, and that is accomplished best by staying well away from current and voltage limits of any component in the system.

Powervelocity.com said:

If there is no benefit in higher voltage, we should be all getting 12v packs with 1000A discharge rates and be happy with all the torque we can get from it.
I will choose my 24s over 20s or 18s in a heartbeat, as the difference in performance is substantial.
And I have no concerns overheating my 18Fet controller running at 100v and 100Amps. The motor MXSUS v2, however, does overheat after 3 minutes running at 9kw but that's expected as that's 3x of its rated power.

John in CR said:

Using higher voltage to reduce I2R losses for the same power only applies between the battery and controller. Regardless of pack voltage for the same torque and rpm (power) the motor gets the same thing from the controller. Our controllers are buck converters to change the DC coming from the battery to exactly what our motor needs. I use higher than necessary voltage for a different reason than you plan, to get higher torque (greater acceleration) all the way through my usual top cruising speeds. That higher performance resulting from higher torque does have a cost in terms of more motor heat, but riding around using the same performance I would with a lower pack voltage has no cost in motor heat. There is more heat in the controller though, which warrants using a beefier controller like you plan. There's some interesting discussion on this topic here https://endless-sphere.com/forums/viewtopic.php?f=30&t=79229.

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