My 1st ebike, request for helpno.1

[Ant0ny]

Hello,

After a year of looking i have taken the plunge and got a kit to convert my Kona Coiler into an e-bike. For a 1st stab i decided to go for the 36V 350W off-road 8fun kit from Alien, I know it could have been cheaper but to get going i thought that it would be a good way to start.

Generally the kit is what i expected knowing that i would want to upgrade a few things (and that anything that i don't use now would be ok for my wife's bike when i get round to it.

So now for my 1st questions on this forum!!!

1. I set the wheel in the rear forks originally by using a single washer on the disk side to get the spacing right to align with the caliper, Then cobbled the rest together to give it a test (10 km), result being generally good other than the wheel made a lot of noise which i put down to possibly an imbalance due to the single washer spacing. So i added a second washer to the other side and noticed straight away that the wheel had become buckled - I will true it up but does anyone know if my thinking of the imbalance is correct and the buckle is a result of this? Also, how much noise should i expect from the motor (running unloaded it sounds like a motor would, but with me on really tends to rhythmically whine.

2. The Phylion XH370-10J battery i've got seems to cut out if it is under too much load (according to Jim at Alien), is this normal? does anyone know what this battery should be able to output? To me it should be able to deal with the 18 or so Amps peak going to the controller? and if it is an over protective BMS what could be done to increase this limit.


ANy advice or tips will be extremely welcome!

 

[Deleted member 4366]

If the wheel buckled, it was because the spokes hadn't been properly tensioned - nothing to do with washers. The BPM hu motor is not symmetrical with regard to the spoke flanges. If the wheel builder didn't take this into consideration, your rim won't be central. You need to dish the wheel a little. The two anti-rotation washers must be fitted and they should go on the inside of the drop-outs with the tabs facing outwards.

The motor should be relatively quiet. A little bit of whine when new is normal. Check that the calliper isn't rubbing on the disc.

Unless you use an ammeter or wattmeter, you've got no way of telling how much you're drawing from the battery. My opinion is that a 10aH battery wouldn't normally be enough for that motor, but Alien have sold loads of kits and bikes with that set-up so it should be OK, but the battery shouldn't cut out. Without a meter it's not possible to say whether it's a weak battery or strong controller. Have you got LEDs to show the battery charge state? If so, do they go down to red brfore cut-out?

 

[Ant0ny]

Hi d8veh,

So i've checked the spokes and it appears that they were never really that tight, i'll true the wheel up and have another go. Concerning the anti-rotation washers, they are fitted but as i didn't want to spread my rear forks that much i've had to fit them to the outside, i can't see that it makes that much difference.

I know that the disc rubs slightly (it was bent during a fall in the alps) but the noise really seems to be coming from the motor. I've read other threads which suggest that it can take a while to bed in so will have to see.

I plan on checking with a watt meter at the weekend, when the battery has cut out and is reset i still have 2/4 leds on (i don't know how linear this is) but the battery only takes 2 hours to charge rather than the 5 specified so assume i have more than 50%. At the point when it cuts (steep up hills) all of the leds will go out but come on again when i let of the throttle.

 

[flecc]

I had one the Phylion 370-10J batteries on long term test for eZee Kinetics from January 2008, the testing done on a setup that could draw 27 amps. I deliberately tortured that battery daily with both a very long gentle climb over 5 miles and a two 1 in 5 hills, deliberately avoiding any pedalling that wasn't absolutely necessary, doing that for six months. It refused to cut out at any time during that test. Afterwards I continued to use that battery for over two years on the same bike, and the first cut-out I experienced was at 20 months old on a long slogging climb.

Based on that, and the assumption that today's version of that battery would be at least as good as the 2008 one, I'd say your battery could well be faulty. I can't say that's definitely the case without knowing how far it's discharged when it cuts out, but it seems very likely based on my experience.

 

[Ant0ny]

So, just done a 20km ride with the wheel trued up and the bike ran almost silently so that is my 1st problem fixed. However, i ran with a power meter today to check what is happening with the battery and it cuts out with a pack voltage of 35 V after drawing a third of the capacity from the pack, I had the impression that each cell could go as low as 3.2 v per cell, not 3.5 v, any suggestions?

 

[flecc]

You are right, that is an early cutout, it shouldn't happen until the voltage drops to around 31.5 to 32 volts. I'd suggest you get back in touch with Alien to get that battery replaced.

 

[JuicyBike]

Is the battery BMS cutting the power, or the controller? Both battery and controller can have a protective logic built-in within some systems.

 

[Ant0ny]

So, the problem is i live in France and needed to get someone to bring the battery over, while they sent the kit direct, otherwise is was 300 pounds to send due to the dangerous goods (lithium battery). With this in mind i have just opened the battery up (void guarantee) to check each cell. There are 9 of them quite happily sitting at 3.8 volts and guess what - one at 3.1 volts. Will get in touch with Alien to see what he can do!

 

[flecc]

I've received and sent lithium batteries by post at normal courier rates, including between countries.

If it's the first cell that's low it's not unusual, it still totals to over 37 volts and you were getting cutout at 35 volts, far too high. That Phylion BMS has a nominal 32 volt cutout, but I don't know if your bike's controller has one as well. I still suspect the battery most though.
.

 

[Ant0ny]

It is the 1st cell that is low, does the battery BMS look at each cell or only the pack? I think that it is the battery BMS that cuts as everything goes including the watt meter which is before the controller.

Just fully charged the battery, took around 2 hours, the cell voltages are as follows;

cell 1 - 3.95
cell 2 - 4.01
cell 3 - 4.17
cell 4 - 4.03
cell 5 - 4.00
cell 6 - 4.00
cell 7 - 3.99
cell 8 - 4.00
cell 9 - 4.01
cell 10 - 4.02

To me it doesn't seem that the charger (BMS) has done a very good job balancing it, is it possible that the cells are ok but it's the BMS which is duff?

 

[flecc]

Very often the BMS is powered by the first cell, so that can account for some voltage drop on that. The BMS does look after each cell individually.

I tend to think it's the battery's BMS that's at fault, on the early cutoff and possibly on the balancing.

 

[Deleted member 4366]

If you can, charge the single cell until it matches the rest. It can be done with any charger that gives 5v, but you must keep an eye on it not to go over what thie other cells are at. With one low cell, it will sag a lot under power causing the BMS to trip. If you can't charge it on its own, try a few charge cycles to see if the BMS can get it a bit higher. it might settle down after a bit.

I have noticed this problem on several of my batteries when I haven't used them for a while, but they do improve after a few charging cycles and normal riding. The range was also substantially reduced. Recently, we've had quite a few forum members also suffering cutting out and low range, so I guess they've got the same problem. Often it seems to be cell 1 and I've heard that some batteries use cell 1 to power the BMS even when the battery is disconnected, but I can't say that this is definitely true, but it probably is.