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The eBike thread
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I like the idea of making my own battery, could I make a better battery for less money ?
Time for a bit of YT. See if this is something you would be interested in. Start with Micah Toll. This is the easiest way, using his Vruzend kit (no soldering / welding)
Not cheap though as the kit is expensive. But you get the idea. You can buy chargers on eBay from about a fiver including shipping.0 -
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You could use hobby king LiPo or LiFeP04, LiFeP04 isn't really suited for ebike use as it's bulky and heavy.
With LiPo you can make a cheap battery that can pull mega amps if you wish and charge at high amps.
Use 30 Amp "genuine" anderson connectors, there are a lot of fakes. I have a crimp tool also, dead handy. The 30 Amp andersons act as very convenient fuses should you cause a short by accident,. they vaporise in your hand.
LiPo poses obvious risks if abused they can go up in a ball of fire but never happened me, never store/charge in the house unattended.
You can use the LiFeP04 batteries also, you got to manage it yourself as there is no BMS so you need to watch that the cell voltages don't go too low or they could be damaged and that can become dangerous.
A BMS has it's own risks, especially for DIY use as it can cause catastrophic failure to the battery if it should fail.
The downside of course in the beginning is that you need an R.C battery charger to balance the cells and make sure they're not overcharged + you need to buy an external power supply for the charger.0 -
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Deleted User wrote: »The Hoverboard battery is fine if you want to have poor acceleration lol
Nonsense.
Acceleration is determined by torque of the motor (nothing you can do about that) and the power applied to the motor
Max power applied to the motor is voltage of the battery * max amps of your controller.
It has nothing to do with the max amps your battery can discharge at (very high for lipo). Power is only restricted if the BMS prevents those max amps to be discharged from the battery. Which doesn't happen with the hoverboard batteries (and yes I know it's not good for the life expectancy of an 18650 cell to discharge it at 3C) 0 -
Nonsense.
Acceleration is determined by torque of the motor (nothing you can do about that) and the power applied to the motor
Max power applied to the motor is voltage of the battery * max amps of your controller.
It has nothing to do with the max amps your battery can discharge at (very high for lipo). Power is only restricted if the BMS prevents those max amps to be discharged from the battery. Which doesn't happen with the hoverboard batteries (and yes I know it's not good for the life expectancy of an 18650 cell to discharge it at 3C)
Torque of the motor + amps give torque.
Turn down the amps you turn down the torque, why do you think people modd controllers for more current which = amps ? why do you think I suggested adding a dab of solder to the shunt in the controller ? to allow more current for more torque.
add voltage and you go faster Lover voltage and you go slower but overall current x voltage gives watts.
More amps require a battery capable of supplying the power.
If you had a controller and were able to adjust it via software you can also see that limiting current limits acceleration, speed can be limited by voltage or software.0 -
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I rode the bollox out of the bike last Sunday during the worst of storm Ciara. Still lasted the guts of 20km. Or do you mean number of charging cycles? I don't give a sh1t tbh. If I get a few hundred cycles out of it (several years use for me taking the bike out maybe once or twice a week), that's fine for the €100 I spent on this pack 0
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I rode the bollox out of the bike last Sunday during the worst of storm Ciara. Still lasted the guts of 20km. Or do you mean number of charging cycles? I don't give a sh1t tbh. If I get a few hundred cycles out of it (several years use for me taking the bike out maybe once or twice a week), that's fine for the €100 I spent on this pack
Well at least you're having fun. 0 -
I rode the bollox out of the bike last Sunday during the worst of storm Ciara. Still lasted the guts of 20km. Or do you mean number of charging cycles? I don't give a sh1t tbh. If I get a few hundred cycles out of it (several years use for me taking the bike out maybe once or twice a week), that's fine for the €100 I spent on this pack
Do you have a link for these ? I assume I solder the wires together.0 -
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Bought another faulty 1000W electric scooter. As expected, turns out the lead acid batteries (*4!) were dead. Replaced them with one of my 58.8V packs and the thing is flying again
So might sell it with both my double packs, which means I will have to buy something else. Would consider spending a bit more to have a higher discharge rate pack, was still considering lipo as per Mad_Lad's advice, but came across this:
Andy Kirby says: don't use lipoOK, I think I fould them on Aliexpress they are $28. So I how many of these do I need ??
Depends on what you want to do and how much you want to spend. If you take it handy with the throttle (or don't use it at all), use mostly the lower levels of pedal assist and don't need much range, 2 will do. If you need more, get 40 -
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Deleted User wrote: »Well I suppose if Kirby says don't use LiPo then don't use LiPo, what would Mad_Lad know about LiPo I suppose ? Not like he built LiPo packs or anything !
Well, we can have a discussion here about using LiPo vs 18650 based battery packs.
The major benefit of lipo is that it can be charged / discharged at much higher rates than lithium ion. This is vital if you need a very high power application and it doesn't matter that it can only work for a very short time at max power. But what does matter is the weight of the pack. It is clear this would be a major benefit for say a remote control helicopter.
Is this a major benefit for an eBike though?0 -
Well, we can have a discussion here about using LiPo vs 18650 based battery packs.
The major benefit of lipo is that it can be charged / discharged at much higher rates than lithium ion. This is vital if you need a very high power application and it doesn't matter that it can only work for a very short time at max power. But what does matter is the weight of the pack. It is clear this would be a major benefit for say a remote control helicopter.
Is this a major benefit for an eBike though?
Depends on your requirements, if like me at the time and you needed high power from a very small pack then yes absolutely it does matter for an ebike.
It's not just about running power for a short time it's about having the power when you need it.
For a long time I was running just 5 Ah at around 60 volts, that gave me about 300 watt hrs of storage, this was plenty for up to 50 Km even with decent hills because I peddled a lot and lost a tonne of weight in the process, if only I had the time to do that again lol. My Bosch Ebike had 400 Watt hrs of storage new, 36v 14 ah.
Small pack for cycling that could give me the amps when needed, for instance, my old bike could do 60 Km/hr so if I was out on a nice summers day and I say a black sky coming or hear a clap of Thunder, I'd yank that throttle to get me home. or a hill I needed to get up quickly, or my legs were tired and I wanted to get up a hill quickly without peddling.
It's super easy to make packs out of LiPo bricks, charging is the only issue if you want to call it that, RC charger and Power Supply and the pack has to be charged in Parallel and then connected back in series/parallel for the bike but to be honest that didn't bug me at all.
If you have a BBS02 or BBSHD then this makes it easier to find a suitable battery these days if you really must have a BMS which is probably good for some people who might find it difficult to monitor cell voltages and the likes.
As I type this I have em3ev.com site open looking at his batteries and he has a LG HG2: ~ 44A Continuous, 55A Max Burst Current, voltage is 52 volts which would be more than enough to run my old MAC 8T motor at 50 Km/hr and still climb plenty of decent hills with no issue this would give me 2.2 Kw of power in a battery that is small and reasonable weight.
It costs 465 Euro's before shipping and import charges though which would make it probably 100 Euro's more expensive ?
I know Paul's batteries are pricey but they're built to the best quality and his reputation on endless sphere is excellent so I would pay more to have a pack of known good quality compared to a battery of unknown quality that might not even have the cells specified. Dodgy batteries are all too common.
He does have cheaper batteries of course with less current capability.0 -
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Geared hub drive pedals even easier than mid drive if battery runs out. Will even bring you home if the chain breaks
But you're right, mid drive is more efficient in a low gear up a steep hill. Is efficiency that important? For the cheaper price of the wheel kit, you can install a bigger battery and still have money left over. Less maintenance too. Nothing to go wrong with a hub motor if gently used (max 250W)0 -
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Geared hub drive pedals even easier than mid drive if battery runs out. Will even bring you home if the chain breaks
But you're right, mid drive is more efficient in a low gear up a steep hill. Is efficiency that important? For the cheaper price of the wheel kit, you can install a bigger battery and still have money left over. Less maintenance too. Nothing to go wrong with a hub motor if gently used (max 250W)
Can you get hubs with integrated controllers?0
https://www.youtube.com/watch?v=rylbFnTgFI8
![[Deleted User]](/applications/dashboard/design/images/defaulticon.png)
https://www.youtube.com/watch?v=u2cgm6ibecY
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