Not just because it never got balanced.due to me not knowing it had to be switched on when charging.

The BMS does its balancing whether you have it switched on or not. The balancing is analogous to a row of buckets with small holes drilled an inch down from the top of the rim. When you fill them up, water will drain out of the holes until they're all at the same level.

Hi Hilly, another thing to consider when deciding whether to go centre drive or hub motor is what type of wheel hub the donor bike is set up for (in terms of the frame). The Planet X London bike that you linked looks like it has a QR through axle on the front, but can’t see what is on the rear from the pictures. Centre drive looks like it would be easier to fit.

 

So what type of axle would be best? say if i was going for the Q128c rear hub motor?

So what type of axle would be best? say if i was going for the Q128c rear hub motor?

Some modern bicycles have through-axles like a motorbike. The frames or forks are characterised by having a hole for the axle instead of a drop-out. You can only fit hub-motors in axles with drop-outs. The type of axle makes no difference with a crank or chain motor.

 

It makes no difference whether the axle is QR or fixed with nuts. It tends to be only the cheapest catalogue bikes that have axles with nuts these days.

 

Rear drop-outs are nearly always 10mm whether you have a 9mm QR wheel or not. In most cases, a motor will fit without having to file the drop-outs, though a bit of dressing to remove the paint is sometimes required. Forks are different. They often have 9mm drop-outs for a 9mm QR axle. so you have to do a bit of filing. Those cheaper bikes with bolted axles normally have 10mm axles and drop-outs.

Edited July 2, 20196 yr by vfr400

Thanks for that. I contacted Planet X and they said the bike comes with quick release front and rear. The guy selling the bike on ebay has changed the forks so i guess that's why it's got a through axle on the front.

 

Some modern bicycles have through-axles like a motorbike. The frames or forks are characterised by having a hole for the axle instead of a drop-out. You can only fit hub-motors in axles with drop-outs. The type of axle makes no difference with a crank or chain motor.

 

It makes no difference whether the axle is QR or fixed with nuts. It tends to be only the cheapest catalogue bikes that have axles with nuts these days.

 

Rear drop-outs are nearly always 10mm whether you have a 9mm QR wheel or not. In most cases, a motor will fit without having to file the drop-outs, though a bit of dressing to remove the paint is sometimes required. Forks are different. They often have 9mm drop-outs for a 9mm QR axle. so you have to do a bit of filing. Those cheaper bikes with bolted axles normally have 10mm axles and drop-outs.

Not all bms are the same most use a bleed off via a resistor crude but it works to a point others use the semi dumb charge- float- drain- trickle and repeat until balanced and require the pack to be switched on to balance and left on charge for longer once the initial charge has completed

You get what you pay for ,a fully intelligent system as used in car packs would be more than most of us would be prepared to pay but still does not show up which cell has the problem just which string and as most are glued/ bonded in the pack is still scrap mr tesla/musk might solve this at a later date

Just another quick concern big battery and higher speed will draw unwanted attention

So what type of axle would be best? say if i was going for the Q128c rear hub motor?

how to estimate the result:

That particular motor is specified as 48V, 328 RPM, 500W.

On 26" wheels, 328RPM = 25.6mph, you need 650W input to maintain this speed.

On 700C wheels, 328RPM = 26.4mph, you need 700W input to maintain this speed.

That means you need to allow 650WH/25.6mph = 26WH per mile.

For your 30 miles trip, you want to arrive at destination with at least 25% reserve in your battery, that means 30*26WH/0.75= 1015WH, or 48V 20AH.

You then need a fast charger, the normal charger would take 8 hours to recharge your battery.

At this rate, your 800 cycles will be all used up within 15 months. If you use a fast charger, you may not have as many as 800 charging cycles.

That's why I think you have to buy a battery that uses LiFePO4 which can take 4A charger and still lets you have 2,000 charging cycles.

That's the requirements for a bike that does 25-26mph. 28mph will burn 20% more WH per mile.

Thanks for that. Surely the weight / aerodynamics of the bike and how much I'm pedalling will also have an effect?

 

8 hours charging time is not a problem.

 

Also as I mentioned earlier I'm not going to be doing the journey twice a day, day in day out.

 

At this stage I'm thinking that a more modest speed on a bike designed for road riding and and a modular kit (which won't have built in obsolescence) will be an upgrade from Haibike.

 

I'll probably install the kit with a smaller battery to make sure it all works the get a feel for the range and the speeds that are achievable then make a decision whether I want to put it through the DVLA test and how big a battery I will need for the commute. Only when all that's done will I sell the Haibike.

 

how to estimate the result:

That particular motor is specified as 48V, 328 RPM, 500W.

On 26" wheels, 328RPM = 25.6mph, you need 650W input to maintain this speed.

On 700C wheels, 328RPM = 26.4mph, you need 700W input to maintain this speed.

That means you need to allow 650WH/25.6mph = 26WH per mile.

For your 30 miles trip, you want to arrive at destination with at least 25% reserve in your battery, that means 30*26WH/0.75= 1015WH, or 48V 20AH.

You then need a fast charger, the normal charger would take 8 hours to recharge your battery.

At this rate, your 800 cycles will be all used up within 15 months. If you use a fast charger, you may not have as many as 800 charging cycles.

That's why I think you have to buy a battery that uses LiFePO4 which can take 4A charger and still lets you have 2,000 charging cycles.

That's the requirements for a bike that does 25-26mph. 28mph will burn 20% more WH per mile.

A 48v 20Ah LiFePO4 battery would be too heavy for a bicycle.

The BMS does its balancing whether you have it switched on or not. The balancing is analogous to a row of buckets with small holes drilled an inch down from the top of the rim. When you fill them up, water will drain out of the holes until they're all at the same level.

Hmm thats interesting.Everything ive learned so far from people says the opposite.when i had my issues recently with the badly balanced bbshd battery.i trickle charged with a mobile phone charger all the cells to the same voltage,when nearly drained. Then when i charged switched on, for the first time ever it went into balancing mode.with the charger turning on and off for several hrs after the green light. Until the cells all were equal at 4.1v. It had never done this before when the battery was switched off during charging.

The balancing is analogous to a row of buckets with small holes drilled an inch down from the top of the rim. When you fill them up, water will drain out of the holes until they're all at the same level.

if one bucket has a small hole at the bottom, all the buckets below it won't balance.

Hmm thats interesting.Everything ive learned so far from people says the opposite.when i had my issues recently with the badly balanced bbshd battery.i trickle charged with a mobile phone charger all the cells to the same voltage,when nearly drained. Then when i charged switched on, for the first time ever it went into balancing mode.with the charger turning on and off for several hrs after the green light. Until the cells all were equal at 4.1v. It had never done this before when the battery was switched off during charging.

You can't see any balancing mode from the outside unless you have a BMS with LEDs that light up when the bleed resistors are open, like the old Ping batteries. The only way you can tell with yours is to put your finger across the bleed resistors when the battery is fully-charged and the charger still connected. You should be able to feel them getting warm. Try it with the battery switched on and off to see if there's a difference.

 

When you thought that you saw your battery in balancing mode, what brought you to that conclusion?

30Q has poor cycle life according to threads on ES from users who have cycle tested them and use them.

ES is known for power bikes with high current demand, a lot of diy packs are made, you have to read between the lines to see what spec they build and how many parallel cells.

So much for the vaunted 30Q then. i thought it was supposed to be the best. with a 14s5p giving 37.5amps continous,well above a bbshd using 24-30amps for moderate periods. i doubt ive charged the battery 70-80 times over the year.

When you thought that you saw your battery in balancing mode, what brought you to that conclusion?

well the charger has a loud cooling fan and i always charge indoors.so im aware of it. The leaflet that came with it said "the charger will continue to switch on and off after charging ,this is normal,this is the battery balancing do not unplug" .However it never did while i had the battery switch off. Since i started recently charging it switched on, the charger does that turning on and off, after the green light. just as the leaflet said it would.

However it never did while i had the battery switch off. Since i started recently charging it switched on, the charger does that turning on and off, after the green light. just as the leaflet said it would.

Did you check to see if it does that with the battery switched off now that you've adjusted the battery?

 

The balancing is basically an overflow system. If the charge MOSFET is open and the charger connected, then you can't stop it from working. If the charge MOSFET is closed, no charging can happen. On some batteries the charge MOSFET is switched off when the battery is switched off, which is why you have to switch them on for charging.

 

When your charger does that switching on and off at the end of the cycle, it's normally a sign that your battery is out of balance.

When your charger does that switching on and off at the end of the cycle, it's normally a sign that your battery is out of balance.

true, but it's also indicating that the battery is being rebalanced.

The LED is set to switch to green when the voltage goes over the 41.5V preset. If some of your buckets need topping up, then it causes the voltage to fluctuate around the preset.

true, but it's also indicating that the battery is being rebalanced.

The LED is set to switch to green when the voltage goes over the 41.5V preset. If some of your buckets need topping up, then it causes the voltage to fluctuate around the preset.

It shouldn't switch on and off. It should stay green in CV mode, when it goes red, it means CC mode, which shouldn't happen when balancing. It's a sign that one cell is substantially higher than the others. The charger goes to CV mode when the voltage is close, so to be in CC mode, the overall voltage must be off.

 

What happens is that charging is allowed until the first cell reaches its high voltage point to switch off the charge MOSFET. The charger will then switch to CV mode and go green. When the battery is out of balance, the overall voltage is below the CV switch-over. The bleed resistor drains down the high cell until the cell is low enough to reopen the charge MOSFET. As the voltage is still well below the maximum, the charger switches over to CC mode and goes red again for a short time until the high cell switches off the MOSFET again. The cycle repeats until the battery is balanced, which will take a long time.

 

You could watch all that happening with those BMSs that had LEDs, which lit up when the bleed resistors are open.

Edited July 3, 20196 yr by vfr400

it's not quite what happens though. When you watch the power consumption (with an energy meter) of the typical 2A charger, you can see it stays at around 83W-87W all the way until the last hours then gradually decreases to 60W, 50W, 40W, 30W etc until about 10W then below 5W when the LED goes green.

If it were to stay on CC until the LED goes green (CV) then you should have seen power consumption goes straight from 83W to 5W without decreasing slowly in the last hour. In other words, the LED does not indicate which charging mode (CC or CV).

I just found a thread on another forum where the guy had converted a Haibike to a road bike by swapping the forks, putting a drop bar on it and putting road wheels / tyres and a bigger chain ring on it.

 

This is the thread

 

I made it to work in 1hr 30m this morning with an average speed of 18.5mph so maybe doing this will give me the increase in efficiency an speed I'm after.

 

It seems like the kit market is really taking off at the moment so maybe if I ride the Haibike until it dies then by that time the kit options will be better.

 

Anyone got any thought on this?

A hub motor is much better for commuting, especially in winter when you have cold hands and hypothermia sets in. Also, the running costs will be much lower as your chain and sprockets would last about 5 times as long.

I've had the current chain and sprockets on the Haibike for just over a year. I think with a 250w motor and by learning to change gears more carefully than you would with an 'analogue' bike you can greatly reduce the wear on the drive chain.

 

How does the hub motor keep your hands warm in winter?

 

I'm not saying that in an ideal world a hub motor wouldn't be better, just trying to make the most of what I've got. Buying a bike and hub kit at the moment and making sure you've got all the right stuff seems like a right old ballache at the moment. It seems like the mid drive kits like the Bafang are taking the lead at the moment. Hopefully in a few years when the Haibike bites the dust the kits will have progressed a bit.

 

A hub motor is much better for commuting, especially in winter when you have cold hands and hypothermia sets in. Also, the running costs will be much lower as your chain and sprockets would last about 5 times as long.

How does the hub motor keep your hands warm in winter?

because you don't have to keep changing gear, so you can keep your fingers together in a warm mit.

Did you check to see if it does that with the battery switched off now that you've adjusted the battery?

 

The balancing is basically an overflow system. If the charge MOSFET is open and the charger connected, then you can't stop it from working. If the charge MOSFET is closed, no charging can happen. On some batteries the charge MOSFET is switched off when the battery is switched off, which is why you have to switch them on for charging.

 

When your charger does that switching on and off at the end of the cycle, it's normally a sign that your battery is out of balance.

ill try charging it off this time to see and check the cell voltages after. in my case where some cells still show more wear than others (the same 4 finish 0.05v lower than others )isnt it wise to always do balancing if they are less than perfect now. it seemed to correct the sagging problem i was having before.the battery goes to the 42v LVC now and seems to handle higher amp draw to the end.

 

when i e mailed electron cycles they said "you have made sure the battery is on when charging?"

Edited July 4, 20196 yr by minexplorer

Mopeds, thought i read somewhere that they could only be run for 30min at a time @ 30mph=15miles. Or was that only 2strokes?

 

Does that battery calc go: 29miles × n wh/m = total wh + (total × 0.25) = grand total wh, maybe?

Anyway? 1kwh+ of battery would be great

 

V.interested in question of charging with battery off vs on, it's not mentioned in the manuals I've seen. I'll try it tomorrow, my batt prob needs a balance! Would like a batt & charger that let me know cells status, give me 50+ more things to worry abouto_O, hehe.

 

Aerodynamics would help speed and if space tight a semi-recumbent with folding bars & pedals good for a narrow entrance hall. http://practicalcycles.com/products/370180--via-vt2-folding-ahead-bicycle-stem-os-318-space-saving-fold-bars-no-tools.aspx

 

Cheers, Mikel.

Edited July 4, 20196 yr by MikelBikel

I just found a thread on another forum where the guy had converted a Haibike to a road bike by swapping the forks, putting a drop bar on it and putting road wheels / tyres and a bigger chain ring on it.

 

This is the thread

 

I made it to work in 1hr 30m this morning with an average speed of 18.5mph so maybe doing this will give me the increase in efficiency an speed I'm after.

 

It seems like the kit market is really taking off at the moment so maybe if I ride the Haibike until it dies then by that time the kit options will be better.

 

Anyone got any thought on this?

 

Nice find! You have the Haibike, go for it! Schwalbe has a wider tyre out this year with fast e-bike certification https://www.schwalbe.com/en/road-reader/schwalbe-e-one.html - wider = more comfortable over a long distance like yours.

 

44 tooth chainwheel = 45 km/h at cadence of 90 + a wide range cassette and how about an aero bar adaptor on your flat bars?

I spoke to the bike shop man this morning, he said it would be extremely expensive to convert it to something like the one in the picture. Basically because most of the components would have to be replaced because road bike and mtb components are incompatible. He also said the geometry of the bike might be a bit dodgy at the end of it : (

 

I'll check those tyres out. I'm put off aerobars by the fact that you can't reach the brakes. people drive like idiots around London, wouldn't like to compromise my stopping distance going down a hill.

 

Nice find! You have the Haibike, go for it! Schwalbe has a wider tyre out this year with fast e-bike certification https://www.schwalbe.com/en/road-reader/schwalbe-e-one.html - wider = more comfortable over a long distance like yours.

 

44 tooth chainwheel = 45 km/h at cadence of 90 + a wide range cassette and how about an aero bar adaptor on your flat bars?