Battery draining 2x as fast on DD motor with similar controller

[Aquakitty]

I suggest having more fun on your commute. Buy more battery and set the power setting on high. Ebikes can be as fun as an amusement park ride, but with no lines and literally pennies a ride, and still chuckle to yourself about the suckers in their steel cages stuck in traffic. If you really want to stick it to the man, as well as have post-apocalyptic transportation, then get some solar panels to charge your ebike(s).

While I totally agree with your sentiment, are you replying to the right thread? My question is basically if this heat/power usage is normal. I've never had a DD hub drive

I will buy a new battery if that's what's going on, I just want to be sure I didn't mess something up. Getting that hot going only 35 KPH?

 

[E-HP]

How many watts does the stock display show with the wheel off the ground and running WOT? Seems like around 70 watts would be "normal".

It spikes to about 200 on first hitting throttle then steadys at about 63.

Seems normal. Very odd on the hot controller.

 

[999zip999]

What's that continuity Grease between the fets and the case of the controller.

 

[Aquakitty]

What's that continuity Grease between the fets and the case of the controller.

Like put some on there? I put that on the connectors but haven't opened the controller. I'm wondering if maybe the open source firmware for this controller would help. It's ZWS model though so not sure exactly what i'd have to do. Maybe I will just buy a different controller lol. They are cheap enough.
Tonight I will test the controller with an infrared thermometer to see how hot it is.

 

[docw009]

Trying to decipher the numbers. I believe you said the whole trip is 7.5 miles and that drains a 500 WH battery (48V a 11.6 AH)? Or did you mean 15 miles round trip?

First is 60 Wh/mile and the second is 30 wh/mile. I could believe the second number is close to reality and you had a not-so-good battery that was really only 9AH.

 

[E-HP]

Well today after a commute home (I used "2" the whole way except for hill at the end, went to "3") and when I got home, the battery was down 2 bars. This is from a there and back commute of about 12 km total (~7.5 miles). 2 bars of the battery down from using "2" nearly the whole way. There are no hills on the way there...

Need a couple more pieces of information. How long is that hill on the way back, and what is the grade? The mid-drive is more efficient on hills, while your hub motor performs better on the flats. If its a long or steep hill, that would explain why your controller is hot at the end of the ride. What is the limiting factor on your system, the battery or controller? You said your motor is warm, controller is hot, and how about the battery?

You might be able to even things up a bit if you implement regen, but you might need to switch your charging routine to charge in town, to avoid overcharging.

 

[Aquakitty]

The entire trip is 7.5 miles/12 km. 6 km one way to town roughly. This battery has Samsung 29e cells. I have had no such problems with this the 30+ times I used it on the TSDZ2 so I have a hard time thinking it's just a bad battery. Running it through the simulator (I used a BBS02) the mileage I was getting seems about right, but that changes with this system obviously. For the record, I own a BBS02, 3 x TSDZ2 and this DD motor, as well as 5 batteries. So I guess my next step is simply switch batteries. That will be a pain in the rear though as all of the batteries are for different styles of bikes.

Anyway, on the way home today, despite the hills, the controller wasn't hot at all (it's out of the bag still). Yet as I mentioned earlier, it was hot on the flats going there. Like almost too hot to touch. What the heck?? is all I can say. And yea it nearly completely drained the battery again. Controller was below 30 degrees on the outside, battery case just felt a tad warm (but could be from sun) and motor outside casing was 40 degrees (celcius). I used an infrared thermometer.

Oh and I thought maybe the battery was draining while sitting, but I tested that the other day, left it sitting attached and switched on overnight but voltage was the same the next day.

Edit: Just another question. I was reading about this controller and found out it is "dual mode" meaning it works without hall sensors. So just now I d/c'd the hall sensor wires and it still seems to work fine (throttle with wheel in the air). If somehow the hall sensors were borked due to maybe the cables being shorted out or something, would that cause the drain?

 

[Aquakitty]

Ok just to bump, I tried the bike without the hall sensors connected. It rides exactly the same. I don't know much about hall vs non-hall sensors, but from reading it seems without hall sensors the motor is 100% all the time? Is this right? Maybe that could be causing the issues?

FTR I went for an mtb ride with battery today and it worked as expected. Didn't even use a bar from like 20+ km mountain biking.

 

[dustNbone]

Unfortunately reading "bars" doesn't really provide much in the way of useful data, especially across different systems. What would be far more useful is actual voltage readings from the battery before and after the same rides, then you at least know you're comparing apples to apples.

 

[Aquakitty]

Unfortunately reading "bars" doesn't really provide much in the way of useful data, especially across different systems. What would be far more useful is actual voltage readings from the battery before and after the same rides, then you at least know you're comparing apples to apples.

I realise that. Earlier I mentioned I have ordered a watt meter so nothing I can do about that at the moment, but I know at least the battery is draining very fast on the hub bike compared to the mid-drive bike.

I'm just trying to understand what disconnected hall sensors means for the motor, I will just search around and look. Just wondering if that could be the issue, if my original install shorted them out or something. Like is it worth taking all the wires apart and testing at this point (till I get the testers etc.).

 

[amberwolf]

Ok just to bump, I tried the bike without the hall sensors connected. It rides exactly the same. I don't know much about hall vs non-hall sensors, but from reading it seems without hall sensors the motor is 100% all the time? Is this right? Maybe that could be causing the issues?

No, it won't cause the issues.

It also eliminates the possibility that you could be running a wrong phase/hall combo, because if you're not using the halls, there are no combos at all.

The only difference between "sensorless" and "sensored" operation is that startup is rougher in sensorless, sometimes you must pedal forward first before the motor will be able to turn on it's own, because it doesn't have the sensors to know what it's position is.

Some controllers that can operate in both modes work in different ways for each. For instance, the Grinfineons I have won't use the sinewave mode unless the sensors are working, and there are some ohter limitations I forget. But these GF's also have a fallback mode where as long as two sensors are working it'll still use sensored mode. Every controller can be different, depending on design.


As has already been stated, if you are going faster on one bike than another, that alone can take twice the power.

If you do not track the speeds you are going, you will never know if this is the case.


It can also be from the acceleration from a stop, and any hill climbing, becuase the DD hub is less efficient than a middrive in the right gear at that; it can easily take twice the power or more.

 

[Aquakitty]

Ok just to bump, I tried the bike without the hall sensors connected. It rides exactly the same. I don't know much about hall vs non-hall sensors, but from reading it seems without hall sensors the motor is 100% all the time? Is this right? Maybe that could be causing the issues?

No, it won't cause the issues.

It also eliminates the possibility that you could be running a wrong phase/hall combo, because if you're not using the halls, there are no combos at all.

The only difference between "sensorless" and "sensored" operation is that startup is rougher in sensorless, sometimes you must pedal forward first before the motor will be able to turn on it's own, because it doesn't have the sensors to know what it's position is.

Some controllers that can operate in both modes work in different ways for each. For instance, the Grinfineons I have won't use the sinewave mode unless the sensors are working, and there are some ohter limitations I forget. But these GF's also have a fallback mode where as long as two sensors are working it'll still use sensored mode. Every controller can be different, depending on design.


As has already been stated, if you are going faster on one bike than another, that alone can take twice the power.

If you do not track the speeds you are going, you will never know if this is the case.


It can also be from the acceleration from a stop, and any hill climbing, becuase the DD hub is less efficient than a middrive in the right gear at that; it can easily take twice the power or more.

I got ya. I just didn't want to accept how much more power this setup can use. Just ruling stuff out I guess, but like y'all say nothing I can do till I can accurately measure the wattage being used.

Thanks so much for the replies though I've learned more about batteries/motors from this than from all my other builds!

 

[john61ct]

Sorry if a repeat

Buy a GrinTech CA v3

 

[Aquakitty]

Update: Well I feel dumb because I didn't know till I happened on another thread that there was a huge array of settings that were adjustable on the KT-LCD3 for my controller. So, I simply turned down the "max current" from 10 to 5, which prevents the wattage from going above about 975 watts. This made it so I use way less battery power (obviously). The only difference I notice is on hills, it's not quite as much boost but still perfectly fine till I get a new battery. Oh and I also took advice and mounted the controller outside of the bag I had it in (rear double rack under a top bag). No heat problem at all now. And whoever mentioned the hills were the issue was right. The hills are really not long but they were the cause of the battery being drained.

Conclusion: DD motor sucks the juice, and I bought more motor/controller than I really need without upgrading the battery. I'll probably build my own battery upgrade for this particular ride in the future but for now it's fine. I do appreciate now how efficient the TSDZ2 is though.