Insanity V3

Make sure it's pure nickel - Nickel plated steel sparks terribly so you definitely need eye protection!
 
Slightly off topic, since you developed the app is there a thread for BMS questions and info?

I'm thinking about charging now and thought maybe the BMS could have functions to control the charge so a cheapo charger could be used rather than an expensive programmable one.

Thanks for the help.
 
Smoke said:
I'm thinking about charging now and thought maybe the BMS could have functions to control the charge so a cheapo charger could be used rather than an expensive programmable one.

I don't have control over the BMS firmware and I can only program what the manufacturer allows.
The BMS will control charging and it will cut out when the cells reach a predefined voltage. On the app, there's also an alarm that sounds when the battery is full.
 
Do you think there is any way to discontinue charging when Bluetooth goes out of range?

I want to charge at work but I'm not sure it's a good idea to leave it charging when I leave my desk. I'm sure I would forget to unplug pretty often so a software solution would be nice.
 
Smoke said:
Do you think there is any way to discontinue charging when Bluetooth goes out of range?

I want to charge at work but I'm not sure it's a good idea to leave it charging when I leave my desk. I'm sure I would forget to unplug pretty often so a software solution would be nice.

If a thermal runaway does happen, there is not much that can be done regardless if you are there or not. It's not like one cell flares up and pulling the plug will stop the chain reaction at all.
Charging it in the office is a bad idea to begin with, you should do it in the parking garage, ideally one that has cameras and a guard.
 
My parking garage is under the office so that seems like a worse idea.

It's going to be an 18650 pack so not as risky as Lipo and only riskier than a laptop because the number of cells is high. If something went wrong, it would be bad. I'm willing to take that risk but I feel like I should try to make sure that if anything happens I'm around when it does.

It would be pretty shitty if I was away eating lunch when my battery burned down the building and my office mates were still in the room.

I'm starting to think about putting a couple rollerblade wheels and a handle on the battery. It will be a convenient way to roll it around (it should be about 20-25 lbs) and if there is a problem, I could pretty quickly drag it by the handle the 50-60 feet from my desk to the exit. If I can do that, it might set off a fire alarm but it wouldn't burn the building.

I don't think any of this is likely but I would rather have a plan and at least try to add a feature that will make sure I'm around to implement it when I need to.

Everything would be better if there was a secure and fireproof outdoor area for E-bike charging where I work, just like the EV chargers they have for cars but I'm pretty sure that doesn't exist and I'm not a bigwig with a Tesla and enough pull to get a charger installed.
 
The BMS control relies on a signal. If your phone goes out of signal range, it couldn't send a command to the BMS to stop charging.
A function like that would have to be programmed into the BMS itself and I can't get access to the BMS firmware.

On the app, there is a function to turn off charging which you could use when you walk away.
 
Just to add......
If you build the battery pack correctly with matched cells and you use the correct charger, they're just as safe as any other EV produced in a factory. Every EV fire happens when there is no BMS and no way of limiting current - the Chinese chargers simply pump voltage into a battery and the cells get hot and go into thermal runaway. There are plenty of options in the BMS that prevent anything from going wrong and, as long as you do things correctly, it'll serve you for many years.
Use new cells, use a BMS, use the correct charger and you will never have a problem.
 
Chinese chargers simply pump voltage into a battery and the cells get hot and go into thermal runaway

Thermal runaway, isn't it primarily caused by overvolting unbalanced cells? But it might have been exactly your point that a balancing charger or balancing BMS is always needed:D

I think there are advantages to only using simple balancer and run the discharge through a separate wire since there already is double protection on a well built system (current limiting in controller and fuse on battery). This to simplify and remove internal complexity and faults from the bms itself. It also lower the discharge resistance (increased efficiency) and lower overall costs.

Discharge would then be protected by controller and fuse but no need for a high current BMS in such setup
 
larsb said:
I guess most of us don't have charger above 10A which bms doesn't protect from and wouldn't hurt the battery. Voltage is regulated even on the super cheap chargers i've had.

I wasn't specific. I've had a 24v Chinese charger which kept pumping constant voltage (regulated and 26v) and constant current (5A instead of 3A). I've also received a 72v charger which was 84v - it was variable current but it wouldn't have helped because the variance only kicks in at 82v.

larsb said:
Thermal runaway, isn't it primarily caused by overvolting unbalanced cells? But it might have been exactly your point :D
See above example. If the Chinese chargers aren't set-up correctly or you don't know what the battery charge rate should be, bad things happen. Some people get a charger and simply plug it in.
Sorry if I was generalising, sometimes I forget what forum I'm speaking on :roll:

larsb said:
I think there are advantages to only using cell balancer since there already is double protection on a well built system (current limiting in controller and fuse on battery).
Any way of balancing cells is a good way :D
As long as they're balanced, bad things generally don't happen.

Ohhh...... Also, only yesterday I spent 2 hours trying to get a charger working (all the manual and print on the charger was in Mandanise) only to figure out it's wired backwards!
It wasn't a cheap charger either.
 
I ordered an Opus charger to test my cells and a $25 Chinese 58.8v 4 amp floor wart style charger.

I intend to carefully look over the charger for any issues and test the output.

At 15s, that's about 3.92v per cell and I bet there is a trim pot for voltage that I can tweak to bring that up a little higher. I need to do some research on cycle life and cell capacity because I want to live in that power wall spot where cycle life is in the thousands instead of hundreds so I still have good range after 6-7 years and 1,400 round trip commutes.

At 4A, I'm not concerned because it's only about 240 watts in to a 12p battery, that's almost a trickle charger for a 1.9 kwh battery.

If everything looks good and the BMS takes care of the battery, my $25 charger costs a lot less than the alternatives.

I know I can get a Cycle Satiator for $300 or so and there is probably some in between but most of it seems just as sleasy and Chinese so I would rather spend $25.

Sorry for the thread detour.

I saw your latest video yesterday.

If you do decide to redo your nickel-tin strip,I think you should explore the possibility of a deepened saddle bag .50 ammo can so that you can do an equal split side to side and maintain the original gasket seal surfaces. I don't know if the batteries stack well in that space but it shouldn't be too hard to figure out how deep you would need to go and decide if it makes sense.

Widening and messing with the gasket surface just seems like a lot more work.
 
@Vortecks: It is good to see that I am not the only one using masking tape so insulate battery poles while building your own pack. :thumb:

I would be always rather careful when connecting big packs of high-current cells.

In regard to the comments above concerning battery charging, risk of fire, etc. personally I see this rather relaxed. Today we all are surrounded by Lithium-based technology.

Be it in your smartphone, tablet PC or simply your Bluetooth headset. And with technology always comes a risk. We have seen big companies as Samsung having fire-related issues with their products.

For those watching out for a charger that doesn't you require to sell your firstborn, e.g. Cycle Satiator, it might be an option to look closely at certain Meanwell power supplies.

From what I know you can use those LED powersuplies such as type CLG-150-48A. There you can adjust constant current as well as output voltage.

Here just a webpage for example:
https://www.arrow.com/en/products/clg-150-48a/mean-well-enterprises

They also have a webpage with all their products:
https://www.meanwell-web.com/en-gb/led-drivers/

Additional to this one could add another circuit monitoring the battery voltage additional to the BMS and simply cut off main power for the charger.
 
Please note: I always admit my own mistakes so no-one else makes the same stupid ones.......

I sat there last night and I had a thought.......
Although I've made sure there won't be any movement on the packs, I can't avoid micro vibrations. If I was to simply put the battery packs in a metal case (as per the videos I've shown) what would happen if the insulator on the end cells wore through?

It's simple........ EXPLOSION!

With the 10s packs like I've got, if you think about it logically, the voltage across the negative terminals between the first and last cell is 9 cells. This means I have 37.8 volts and 350A exposed if the insulator wears through.

I need to re-design the casings to allow for some extra padding on the ends. This means I can't use the ammo boxes 😢
I feel some aluminium fabrication coming on!
 
can you fit a silicon rubber mat? 1-2mm thick strip towards the cells should take care of the risk and the added heat insulation would probably not be too bad.
Or some layers of glass fibre cloth and epoxy, 0.5-1mm will probably be enough

you can solve it :D
 
HolgiB said:
In regard to the comments above concerning battery charging, risk of fire, etc. personally I see this rather relaxed. Today we all are surrounded by Lithium-based technology.

It's not the Lithium, it's the ammount of Lithium cells. A laptop might have a 5s3p pack, that's 15 cells. If they all cook off, that's going to be some excitement but it would probably need additional fuel to start a building fire.

My pack is going to be 180 cells or maybe up to 216. I have a feeling that if all of them burn, that will create enough heat and fumes to ignite things like cubicle walls that probably wouldn't burn with a laptop fire and set off fire alarms and sprinklers that probably aren't sensitive enough to detect a laptop fire.

Chances are low but it's not zero and I can't trust my co-workers to grab the battery and run like hell to the exit if it starts smoking or smelling funny.
 
Vortecks said:
larsb said:
you can solve it :D

You're correct!
A 5.56mm ammo box is just the right size :D

I just got my cells today and I put them in to an ammo can for safe storage. It happens to be the early style long side latch .50 ammo can and in pretty good condition.

If for some reason your 5.56 ammo can doesn't work out and you have trouble finding a .50 like mine, let me know and we can make a deal.
 
I admit when I've made a mess of things......
I found some aluminium boxes the perfect size for the batteries but..... I fitted them on the bike and now, I can't ride it because they're far too wide.
Back to the drawing board :(
V2 of the battery is looking much better though :D
 
Smoke said:
My offer of a old style .50 ammo can still stands.

Cheers mate but I did buy a couple of the 5.56mm cans which are identical to the older .50 cal ones.
The trouble is, because I made the pack with the batteries on their side, it makes it about 230mm wide which is way too much. I bought some other boxes from RS which are the perfect size and I can get on it, grip the boxes with my thighs but It's virtually impossible to peddle.
I've now ripped the packs apart and I've got the perfect solution for mounting it......watch this space :D
 

Attachments

  • Boxes mounted.jpg
    Boxes mounted.jpg
    163.5 KB · Views: 1,519
Not quite identical, the hinge and latch are on the long sides, not the short sides, if you mount it sideways over the top tube, the latch side would face the seat or the headset.

I need to watch your latest video to see the interference I guess.

Oh, by the way, my BMS came in. I'll buy the app as soon as I get my pack built up.
 
Smoke said:
I need to watch your latest video to see the interference I guess.

That video won't be for a couple of weeks..... I have to give my Patreon supporters something for their money :D
 
I really should update this thread but I think it should be moved now to 'E-Scooter and Motorcycle' section.
IMG_20190317_141344_zps66gfqsm1.jpg
 
That machine is looking good! Now that you've got your battery out of the way; it is really coming together. I'm looking forward to seeing that bike in action in its road legal format. :bolt:

Watching your videos has inspired me to dedicate more time to plan things out for my ebike. Normally; I hastily slap things together during ebike season just to get rolling. I've spent some months this winter doing more planning and fine tuning for my build and it is paying off so far.
 
Back
Top