The eBike thread

SCOL

Very happy with my bike I have done over 100km so far, got her up to 52 KPH

A question about the battery. After using the bike should I let everything cool down before charging it ? or does it matter ?
also as I'm using a mid drive what would the best gear ratio for the bike ?
I have 32-12 tooth, normally I just leave it on the 12 tooth.

John Hutton

SCOL wrote: »

Very happy with my bike I have done over 100km so far, got her up to 52 KPH

A question about the battery. After using the bike should I let everything cool down before charging it ? or does it matter ?
also as I'm using a mid drive what would the best gear ratio for the bike ?
I have 32-12 tooth, normally I just leave it on the 12 tooth.

I basically use the gears to ensure that it never pulls big watts and strains the motor

Keep it spinning fastish without straining seems to be the way to go

SCOL

SCOL wrote: »

Very happy with my bike I have done over 100km so far, got her up to 52 KPH

A question about the battery. After using the bike should I let everything cool down before charging it ? or does it matter ?
also as I'm using a mid drive what would the best gear ratio for the bike ?
I have 32-12 tooth, normally I just leave it on the 12 tooth.

Ideally, if the battery is warm let it cool before charging and unless you intend to use the bike soon again only charge to around 50%, batteries are stressed more the longer they are at a high state of charge and also the hotter they get.

If the battery feels warm on the outside of the case then you can be sure it's a lot warmer inside.

loughside

SCOL wrote: »

Very happy with my bike I have done over 100km so far, got her up to 52 KPH

A question about the battery. After using the bike should I let everything cool down before charging it ? or does it matter ?
also as I'm using a mid drive what would the best gear ratio for the bike ?
I have 32-12 tooth, normally I just leave it on the 12 tooth.

Are you leaving it on the 12 ALL the time? You`ll end up blowing the motor if that`s the case, use the gears to keep your cadence up especially on the hills - those motors hate being dragged.

Joe1919

SCOL wrote: »

also as I'm using a mid drive what would the best gear ratio for the bike ?
I have 32-12 tooth, normally I just leave it on the 12 tooth.

The primary nylon gear also commonly gets damaged from using high gears, especially when starting from stationary and using throttle. The best setup if you dont want to use gears is the hub motor.

.

unkel

Jesus that's bad. Is that yours? Must have taken a hell of a lot of abuse. Like putting through at least 2-3kW to that 750W motor for prolonged periods of time and that in a high gear too, probably with a heavy rider?

Joe1919

unkel wrote: »

Jesus that's bad. Is that yours? Must have taken a hell of a lot of abuse. Like putting through at least 2-3kW to that 750W motor for prolonged periods of time and that in a high gear too, probably with a heavy rider?

No, its a general picture of Bafang. I have a TSDZ2 but has similar setup and problems. The nylon gear engages with the tooted end of the steel motor shaft. Its under maximum stress at take off from stationary, especially if bike in high gear and little assistance/weak pedal power from rider. If its start to slip at all, it will tear and shred the teeth. There is a brass replacement (about 20 euro?) but it can be noisy. Some argue that nylon is better as it acts as a sort of mechanical fuse by shredding and preventing further damage.

I remember those nylon gears were an issue in the MAC hub motors and similar but Paul from EM3EV later sold an upgraded motor with much better gear material, and later on again a much heavier clutch, no matter how much power or current I put through it, 3.5 Kw from the battery I had no issue with gears except the old clutch failed, this was the first gen clutch not the heavy duty one. They were dark grey if I remember correctly.

SCOL

I got my 58.8v charger in the post today. I got 2 e-scooter battery packs wired in series ( 29.4v each ) each of
the packs have a BMS.
I have the charger plugged into one of the packs and the charger light is flashing red. Is this the correct way to charge them up ?
On my other charger it's just a red light and then it charges it goes green.

unkel

SCOL wrote: »

I got my 58.8v charger in the post today. I got 2 e-scooter battery packs wired in series ( 29.4v each ) each of
the packs have a BMS.
I have the charger plugged into one of the packs and the charger light is flashing red. Is this the correct way to charge them up ?
On my other charger it's just a red light and then it charges it goes green.

:eek:

Surely, you are not trying to charge a 24V battery with a 58.8V charger???

SCOL

SCOL wrote: »

I connected 2 hoverboard batteries in series for the bike and it's working great
now I need to buy a charger.

Do I buy a 29.4v charger and charge each pack up separate ?
or is it possible to charge them up at the same time ?

unkel wrote: »

:eek:

Surely, you are not trying to charge a 24V battery with a 58.8V charger???

back on the 23rd March I wrote up:
I connected 2 hoverboard batteries in series for the bike and it's working great
now I need to buy a charger.

Do I buy a 29.4v charger and charge each pack up separate ?
or is it possible to charge them up at the same time ?

and you came back with:
You can charge them up at the same time. That's what I do. You will need a 58.8V charger.

SCOL

Unkel
How do you charge up your packs ? How long would it take if I was to charge them up seperately with a cheap 29.4v €10 charger ?

SCOL

I need to buy a charger for these e-scooter packs they are 29.4v 6a each. I have 2 in series and I'm going to make up a four pack
2 parallel to make up a 58.8v. I'm going to use this as a spare and also hoping to do a few long spins this Summer.

What's the best way to charge them ?

I was looking at a cheap €10 29.4v 2a charger would this take a long time to charge them separate ?
Can it be charged by a 58.8 charger ? Is it possible to get a cheap 29.4v 6a charger would this make much
of a difference in charge time ?

What's my best option ?

Joe1919

SCOL wrote: »

I need to buy a charger for these e-scooter packs they are 29.4v 6a each. I have 2 in series and I'm going to make up a four pack
2 parallel to make up a 58.8v. I'm going to use this as a spare and also hoping to do a few long spins this Summer.

What's the best way to charge them ?

I was looking at a cheap €10 29.4v 2a charger would this take a long time to charge them separate ?
Can it be charged by a 58.8 charger ? Is it possible to get a cheap 29.4v 6a charger would this make much
of a difference in charge time ?

What's my best option ?

Hi. You need to know what you are doing when it comes to batteries and charging, so be careful. Batteries are a fire hazard. A little knowledge can be a dangerous thing! Anyhow, in theory a nominal 6ah battery fully charged with a nominal 2 amp charger should take about 3 hours but it can vary a little from this.
PS Don't buy a 6 amp charger. It will charge the battery too quickly and heat/damage the battery. A 2 amp charger is big enough.

insular1

Last of my parts arrived last week and finished my build at the weekend. Really not happy with my cable management but until I can shorten the cables and solder new connections the insulation tape will have to do.

Overall delighted with the build! Didn't bother installing pedal assist but full throttle it cruises at about 45km/hr on the flat. The resistance of the direct drive motor without power isn't too bad at slow speed in low gears but definitely notice it when trying to go quicker. Definitely not something I hope to ever have to cycle far on a flat battery.

It's surprisingly quite! Really very little sound at all, the bike itself makes more noise than the motor. Very happy with that.

One question, I got the SW900 display with the kit and using some online guides it appears the current limit is set to 12Amps. The controller I have is supposed to be capable of 20Amps. Most of the online guides recommend leaving the current limit at whatever the factory set it at but if my controller can take 20Amps would there be any harm in changing this figure on the display? What could I expect if I did this? Better acceleration, higher top speed or just a fried controller?

insular1

insular1 wrote: »

Last of my parts arrived last week and finished my build at the weekend. Really not happy with my cable management but until I can shorten the cables and solder new connections the insulation tape will have to do.

Overall delighted with the build! Didn't bother installing pedal assist but full throttle it cruises at about 45km/hr on the flat. The resistance of the direct drive motor without power isn't too bad at slow speed in low gears but definitely notice it when trying to go quicker. Definitely not something I hope to ever have to cycle far on a flat battery.

It's surprisingly quite! Really very little sound at all, the bike itself makes more noise than the motor. Very happy with that.

One question, I got the SW900 display with the kit and using some online guides it appears the current limit is set to 12Amps. The controller I have is supposed to be capable of 20Amps. Most of the online guides recommend leaving the current limit at whatever the factory set it at but if my controller can take 20Amps would there be any harm in changing this figure on the display? What could I expect if I did this? Better acceleration, higher top speed or just a fried controller?

Congrats on the build, nice and neat compared to my rats nest of a 1st build back around 2010 + 20 Kg Battery! :eek:

The controllers these days, some are sinewave and the motor will be much quieter as a result. Geared hubs will be notably noisier.

More current gives more torque, more voltage for speed, 12 amps is pretty low for a hub motor, particularly a direct drive hub, 20 Amps would be a little better but still not provide much hill climbing power, ok to me at least lol, remember I was running around 5.5 Kw through a hub like that it was mental. I think I must have been pulling 80 odd amps from the battery!

Your real limitation here will be the battery, you got to keep within the specs or it will have a very short life.

What are the specs of your battery by the way ? there are ways to mod the controller but I don't know what controller you have.

unkel

Deleted User wrote: »

I was running around 5.5 Kw through a hub like that it was mental. I think I must have been pulling 80 odd amps from the battery!

72V battery? If so close enough to 80A alright

unkel

unkel wrote: »

72V battery? If so close enough to 80A alright

Close enough, 66.4 volts hot off the charger charging to 4.15 volts per cell, I was running 16s.

I modded the controller for 80 amps by applying tiny amounts of solder to the current shunt until I got the result I wanted. I was amazed it never fried running 80 amps from a 40 amp controller and that wasn't peak power either.

Acceleration was so quick that max current was being pulled for a short time and even steep hills didn't fry anything which I can assume was related to going so fast up hills, the motor wasn't bogging down which helps a lot to prevent heat buildup.

Those were the days.

insular1

[Deleted User] wrote: »

Congrats on the build, nice and neat compared to my rats nest of a 1st build back around 2010 + 20 Kg Battery! :eek:

The controllers these days, some are sinewave and the motor will be much quieter as a result. Geared hubs will be notably noisier.

More current gives more torque, more voltage for speed, 12 amps is pretty low for a hub motor, particularly a direct drive hub, 20 Amps would be a little better but still not provide much hill climbing power, ok to me at least lol, remember I was running around 5.5 Kw through a hub like that it was mental. I think I must have been pulling 80 odd amps from the battery!

Your real limitation here will be the battery, you got to keep within the specs or it will have a very short life.

What are the specs of your battery by the way ? there are ways to mod the controller but I don't know what controller you have.

The battery is 10.4 Li-ion made of LG LGEBM261865 from Pswpower. Per their spec sheet its 4P13S with a continuous discharge current of 30A and a pulse/Max discharge current 50A. So in theory should be fine to increase the current? I'm not too bothered as at present it's fast enough for me even up hills but always nice to know I could experiment a bit. Out of curiosity what was your speed up hill with that set up?

Not really sure what type of controller I have but it's the same as the one in the attached picture.

Thanks for all the help in here. Really has been an enjoyable process!

insular1

insular1 wrote: »

The battery is 10.4 Li-ion made of LG LGEBM261865 from Pswpower. Per their spec sheet its 4P13S with a continuous discharge current of 30A and a pulse/Max discharge current 50A. So in theory should be fine to increase the current? I'm not too bothered as at present it's fast enough for me even up hills but always nice to know I could experiment a bit. Out of curiosity what was your speed up hill with that set up?

Not really sure what type of controller I have but it's the same as the one in the attached picture.

Thanks for all the help in here. Really has been an enjoyable process!

You'd notice a difference from 12 - 30 amps alright. Eventually get a geared hub and you'd have even more torque from the same battery and controller. I'd have to see inside your controller to see whether it would be capable of higher current but it should be easy enough to get 40 amps depending on the size of it, the FET's it uses and also the ability of the controller to dissipate heat. It looks like it has 12 FETs judging by the controller but I can't be sure. 12 should easily handle 40 amps battery current.

All you'd have to do is put a tiny dab of solder on the current shunt and you would increase the current, but you really have to add a dot at a time or the current could shoot way up.

With the 5.5 Kw setup I was able to climb hills at 50-55 Km/hr, decent hills too but one word of warning, the stock motor phase wires will heat up at more than 1 Kw and you need to keep an eye on that, I was loosing a lot of power heating the wire to the motor until I re-wired it with 12G alpha wire ecowire, brilliant stuff and amazingly thin, can fit through the motor axle no problem.

A programmable controller is dead handy because you can make adjustments based on the motor and battery you have.

unkel

Sold another big electric scooter after I "fixed" it: replaced dead lead acid with lithium ion batteries. Also "overclocked" it to 52V. Only had a few trips on it, but I will miss it, seriously comfy and fast (1000W as standard)

Got my new 7S33P packs from China last week. These are brilliant. I have combined them into two separate 14S3P packs and I actually only need one of them to give me plenty of range. With both I could cycle to Cork (nearly)

insular1

Thanks mad_lad. I think I'll hold off modifying it for a while. I'm enjoying it enough at present. First modification I need is a bigger chainwheel though as 42t can't keep up with the motor on even the slightest down hill. If I get bored after that I'll stay playing with the controller.

unkel wrote: »

Sold another big electric scooter after I "fixed" it: replaced dead lead acid with lithium ion batteries. Also "overclocked" it to 52V. Only had a few trips on it, but I will miss it, seriously comfy and fast (1000W as standard)

Got my new 7S33P packs from China last week. These are brilliant. I have combined them into two separate 14S3P packs and I actually only need one of them to give me plenty of range. With both I could cycle to Cork (nearly)

Is that escooters like the xaomi M365? Damn 1000w in one of those! What sort of top speed you get?

7S33P? Where'd you get those? Get a good price? Thinking about building a cheap second battery to get some experience on the battery building side of things next and also cause my 10.4Ah one only gets me about 25km. More than enough for my current needs but would be nice to have the option of a longer range.

unkel

Haha, no the 33 was a typo

If you want to build a battery yourself, you are in for a bit of a learning curve if you want to do it properly and safely. YouTube is your friend here! The scooters I have fixed and sold so far were all big fat powerful heavy adult scooters. Not the sleek small Xiaomi type scooters

insular1

unkel wrote: »

Haha, no the 33 was a typo

If you want to build a battery yourself, you are in for a bit of a learning curve if you want to do it properly and safely. YouTube is your friend here! The scooters I have fixed and sold so far were all big fat powerful heavy adult scooters. Not the sleek small Xiaomi type scooters

Yeah I've been watching a few videos on it and been put off by how time consuming it's be to solder all those tabs and get the BMS on right. Might just try connecting some cheap 24v batteries from Ali express in series first to dip my toe. See if I get hooked. I'll keep an eye on prices anyway.

Where do you get the scooters? Adverts? I had been looking at getting one for the craic before but never thought of looking for a fixer upper. Will be a while before I have the money for another project anyway.

unkel

No need to solder / weld if you use something like the Vruzend kit.

And yeah, I buy the broken scooters on adverts and sell them on there too

Jeff2

Hi.

This is not mine but does this wiring look wrong for 4 12v battery pack on an electric bike.

SlowBlowin

Jeff2 wrote: »

Hi.

This is not mine but does this wiring look wrong for 4 12v battery pack on an electric bike.

Cant see it ?

Jeff2

Hi.

This is not mine but does this wiring look wrong for 4 12v battery pack on an electric bike.

https://imgur.com/a/x5fRvWz

Jeff2

I try code on phone to embed it.

SlowBlowin

Ignoring the connectors/wiring do you know what voltage the electric bike is ? Its all wired parallel, so the final output will be 12v (assuming 12v modules).. A bike is more commonly 36v or 48v or more..