Upgrade my controller?

Gazzgo

Pedelecer
Jan 6, 2018
27
6
49
Lancaster
Hi

Still new here and learning!

I have 250w Dillinger kit which is helping me greatly. However this evening I went out for a short (8 mile) ride at dusk. I hadn't charged the battery since I rode to work the previous day (20 miles on full assistance - level 5).

After the commute to work the battery meter hadn't dropped a bar. Today in the cold it quickly dropped 2 bars but left 3. On climbing a really steep hill the whole unit cut off. I switched off and on again and shortly after it did the same. I also have my lights running from the same battery (led's).

Once up the hill it performed without issue all the way home. My thoughts are the controller supplied with the kit has a 30v cut off and perhaps with all this load in the cold with a part used battery it had dropped under 30v? Once home I checked the battery voltage 36v no load before charging.

I was considering adding solder to the shunt to increase the amps a little as the motor is rated at 350w and the controller is 7a nominal 15a max. Although I've never seen more than 450w in the display at max load climbing at slow speed.

So should I upgrade this controller to a different one or just add a little solder to the shunt and be aware of part charged, cold weather performance?

The battery is brand new Samsung cells 470 Wh (36v 13ah).

If I change controller will I need a new led display? Any advice on a good quality sensibly priced compatible controller? Maybe with a slightly lower voltage cutoff :) I wouldn't want to run more than 500w into the motor. I think that would be more than enough... or am I wrong?

Advice and thoughts greatly received.

P.S. My future hopes are to make a 2 wheel drive ebike... with a motor in each wheel, but that's way off in the future!

P.P.S. If you're someone reading this wondering if you should get an ebike... do it! They are brilliant! Even low power legal ones a great.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,780
The European Union
Hi

Still new here and learning!

I have 250w Dillinger kit which is helping me greatly. However this evening I went out for a short (8 mile) ride at dusk. I hadn't charged the battery since I rode to work the previous day (20 miles on full assistance - level 5).

After the commute to work the battery meter hadn't dropped a bar. Today in the cold it quickly dropped 2 bars but left 3. On climbing a really steep hill the whole unit cut off. I switched off and on again and shortly after it did the same. I also have my lights running from the same battery (led's).

Once up the hill it performed without issue all the way home. My thoughts are the controller supplied with the kit has a 30v cut off and perhaps with all this load in the cold with a part used battery it had dropped under 30v? Once home I checked the battery voltage 36v no load before charging.

I was considering adding solder to the shunt to increase the amps a little as the motor is rated at 350w and the controller is 7a nominal 15a max. Although I've never seen more than 450w in the display at max load climbing at slow speed.

So should I upgrade this controller to a different one or just add a little solder to the shunt and be aware of part charged, cold weather performance?

The battery is brand new Samsung cells 470 Wh (36v 13ah).

If I change controller will I need a new led display? Any advice on a good quality sensibly priced compatible controller? Maybe with a slightly lower voltage cutoff :) I wouldn't want to run more than 500w into the motor. I think that would be more than enough... or am I wrong?

Advice and thoughts greatly received.

P.S. My future hopes are to make a 2 wheel drive ebike... with a motor in each wheel, but that's way off in the future!

P.P.S. If you're someone reading this wondering if you should get an ebike... do it! They are brilliant! Even low power legal ones a great.
Battery sag... we need to know the type of Samsung cells, they make several different ones ;) And the gradient of the hill would help too.
 

Gazzgo

Pedelecer
Jan 6, 2018
27
6
49
Lancaster
Thanks for the quick reply

Dillinger say this;

"Samsung 26F cell is a 2,600mAh Lithium ion cell manufacturer by Samsung SDI for various applications. The longevity and stability of this cell at low to medium discharge loads make it ideal for this conversion kit. The cells are protected by an advanced BMS that controls everything related to the discharging and recharging of these cells to ensure they last a very long time and maintain good performance over the lifetime."

Hill was variable fairly short maybe 20-25 degree, sorry difficult to tell. But short and took a standing effort in low gear to crest it without assistance once the motor stopped!
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,780
The European Union
I feel your pain... I have the same cells in my 10.4 Ah bottle battery.

Use a lower assistance level and pedal harder, your battery will help you then. It is incapable of pulling you up steep hills without you giving any input.

Do not try to modify the controller that battery isn't up to anything more than about 10 Amps constant on hilly terrain. That isn't so bad if like me you provide 150 W of leg power.

What went wrong is you didn't charge it before going out and you were just a couple of volts above LVC, if you charge to full before going out it will be fine.
 

Gazzgo

Pedelecer
Jan 6, 2018
27
6
49
Lancaster
Thanks

I was certainly pedalling hard but I now also remember I still had it on level 5. I normally drop it to level 1 or 2 if I'm going up a steep, slow hill so that the motor isn't trying to achieve max speed. Its around the speed that I'm going so that is just fills the gaps in my pedal strokes.

10a constant is a bit naff really. I would have expected better of this kit. You live and learn I guess.

I'll make sure it's fully charged next time and always!
 
D

Deleted member 4366

Guest
How old is the battery? You need to establish the reason for cutting out before doing anything. Does the LCD go off when it cuts out?
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,780
The European Union
Thanks

I was certainly pedalling hard but I now also remember I still had it on level 5. I normally drop it to level 1 or 2 if I'm going up a steep, slow hill so that the motor isn't trying to achieve max speed. Its around the speed that I'm going so that is just fills the gaps in my pedal strokes.

10a constant is a bit naff really. I would have expected better of this kit. You live and learn I guess.

I'll make sure it's fully charged next time and always!
What you can do is get a second battery and connect them in parallel, you can climb mountains in assistance level 5 then :)
 

Gazzgo

Pedelecer
Jan 6, 2018
27
6
49
Lancaster
battery is 3 weeks old as is the kit. Everything went off and come back on with a reset. It would appear that the low voltage threshold had been reached due to the combination of factors discussed.

I was considering upping the current to everything to increase assistance but maybe not now.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,780
The European Union
I have gone to the dark side of the force - I use LiPo bricks :D
 
D

Deleted member 4366

Guest
A new 13Ah battery shouldn't shut down with a 15A controller until it's empty.
 

Gazzgo

Pedelecer
Jan 6, 2018
27
6
49
Lancaster
A new 13Ah battery shouldn't shut down with a 15A controller until it's empty.
The display showed 3 bars, the voltage measured at home was 36v but it did shut down under heavy load. Lights on, climbing a steep hill slowly as per my description. Controller has 30v low volt cut off according to specs.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,780
The European Union
A new 13Ah battery shouldn't shut down with a 15A controller until it's empty.
Samsung 26F is the keyword d8veh. Even in 5P those cells are incapable of giving 15 A constant without sagging badly.
 
D

Deleted member 4366

Guest
OK, I missed the bit about 20 miles on level 5. that would flatten any battery. 36v is the recovery voltage. It was most likely running at about 33v and sagging down to 30v.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
11,939
4,631
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West Sx RH
So the lesson is to charge my battery before a ride :)
If you want more range stay out of assist 4 & 5 and just use these for hills other wise try and use more pedal power in 2 & 3 on flatter ground.
 

Gazzgo

Pedelecer
Jan 6, 2018
27
6
49
Lancaster
I know. I was trying to see if the battery level meter works. It doesn’t seem very good. Doesn’t move then suddenly drops 2 bars out of 5 which is actually almost flat it would seem.
I’ll just use miles travelled and how I’ve used the motor to gauge the battery I think.


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