I burned my new 48V controller with a 52V battery

[Robert S]

Hello ESFMs,

I have got a overvoltage protection error on a new build. Do I need to buy another controller? If so, what do I have to look out for?
Here are the facts:

Bought this kit:
Motor: 1000W geared rear hub motor
Controller: Rated voltage 48V, Limit current 28A, Nominal current 14A, rated power 1000W
Display: XT-LCD W108
https://www.aliexpress.com/item/Free-Shipping-36V-250W-350W-500W-1000W-powerful-motor-wheel-No-Battery-Electric-MTB-road-bicycle/32895012500.html

And bought this battery:
Hailong 52V14ah, Continuos discharge current 25A-30A, Peak discharge current 45-60A
https://www.aliexpress.com/item/Hot-sale-48V10-4Ah-B-05-ebike-battery/32690721323.html

More info:
Display shows continuously overvoltage protection error (Er07) after turning on the battery.
When I have the motor disconnected the display only shows this error. With motor connected I first get another error (Er30) and after some seconds with the controller getting warmer I get the overvoltage protection error. I cant find the Er30 in the display manual and there is not much information about it.
I opened the controller and found that there are some copper strings from the power supply cables disconnected (see attached photo) Could this cause malfunction?

Thank you in advance for any advice!
Robert

 

[pwd]

Hi Robert,

I cannot see your attached photo...
my first guess is that the controller has be programmed for a 48V battery instead of a 52V battery. The 48V battery max voltage would be something around 54.6V and the 52V max voltage would be something around 58.8V. The controller is probable complaing about that. If it can be reprogrammed; that could fix it. Was your battery fresh off of the charger?

 

[Robert S]

Hey pwd, thank you for your advice!

I now attached the photo, where you can see one string disconnected on the black cable. The red cable power has also some damages strings.

You are most certainly right with the voltage of the controller being 48V and not 52V. Unfortunately the display I got with the controller has no such option to adjust the voltage. If I would for have a display with that function, this would be the way to solve it? Is there another way?
Which controller and display would be a good replacement for my build? The motor is geared 1000W brushless.

 

[SlowCo]

If your controller is getting warm just by plugging in the battery and without running the motor then there is another problem than over voltage. Is the polarity correct (+ to + and - to -)?

 

[docw009]

I would not be concerned about the stray thread of wire in your picture.

You might be overvolted, A 52V battery normally is used from 58.8 to 45V, while a 48V battery goes 54.6 -42V. If you're going to build ebike kits, you really need a voltmeter. Verify that your 52V battery is actually above 55 volts to confirm the overvoltage condition,

If it is, then I would run the battery down below 54Volts and try it again on the controller. This will tell you if your controller really works. For me, I would just use another ebike to do that, but you will need to find a safe way to drain it. You're on your own here. You need an appliance that will also work on DC. I've found that my wife's hair dryer will spin and take almost 3 amps at 52V DC. Maybe 5-10 minutes to bleed off 4V? Don't go away and let the battery run flat. That will ruin the battery. or the appliance might overheat too. Also, you're only at 50V, but if you had wet fingers, 50V will bite you. Be aware of safety. Lots of bad things can happen with loose wires and an ebike battery.

So now, if the kit runs, you can get a 48V charger (not expensive) and partially charge your current battery. You will go slower and lose 20% of your capacity but it might suffice as opposed to buying a lower voltage battery.

Changing controllers? You have a nice kit with molded round connectors, if I believe the pictures. Controllers that use those are hard to find as stand alone items. Any 25A controller should work, but it will probably come with cheap JST connectors and you will have a terrible splice job to connect your old peripherals. Maybe your vendor can sell you a higher voltage model that uses the same connectors.

 

[Robert S]

Thank you for all your good ideas on this problem! I found this battery has a usb connector. So i can discharge safely (and slowly) via this port. The poles for sure are connected correctly (++, --). Fully charged, the battery gives me 58V.
I just opened the controller and it looks (and smells) burned and damaged (see attached image). So I probably caused this damage with just the 52V battery. So much to the overvoltage protection...

Now I need another controller (and display?). Any recommendation would be welcome. I cant really find 52V controllers. What would be a good 48V controller to do the job? Also I guess to avoid the problem I could buy a 48V charger for not fully charging the battery and avoid damages with 48V controllers.

Thank you guys again for your experienced help on this.
Greetings Robert

 

[Robert S]

I burned my new 48V controller with a 52V battery and I´m a little alone in my region of Colombia(Latin-America) as ebikes have not gotten here by now.

Which controller can I buy to get my build working?

Rewiring is not the problem, but I did not find effortable 52V controllers on the web and I don´t know which 48V controller has good parts to use with my 52V battery. And I would also need to get a new display, as the one I have can not be adjusted to 52V.
Thank you guys very much in advance!

my kit:
Motor: 1000W geared rear hub motor
Controller: Rated voltage 48V, Limit current 28A, Nominal current 14A, rated power 1000W - burned
Display: XT-LCD W108
https://www.aliexpress.com/item/Free-Shipping-36V-250W-350W-500W-1000W-powerful-motor-wheel-No-Battery-Electric-MTB-road-bicycle/32895012500.html

my battery:
Hailong 52V14ah, Continuos discharge current 25A-30A, Peak discharge current 45-60A
https://www.aliexpress.com/item/Hot-sale-48V10-4Ah-B-05-ebike-battery/32690721323.html

 

[Volt_Ampere]

I can't believe they used 50V caps in a 48V controller! Very marginal design.

 

[SlowCo]

That can't be right. Does the label say it's a 48V controller? It almost seems they sent you a 36V controller.
A normal 48V controller should be able to handle up to 60V. But not with 50V caps in there. I would claim a new controller with the seller as they sent a wrong one.

 

[billvon]

That can't be right. Does the label say it's a 48V controller? It almost seems they sent you a 36V controller.
A normal 48V controller should be able to handle up to 60V. But not with 50V caps in there. I would claim a new controller with the seller as they sent a wrong one.

Agreed. The LM317T is a regulator that can handle a max input of 41.5 volts, so you _might_ get away with a 36V system (42V max battery voltage.) If it's a controller for 48 volts nominal that means it has to handle ~56 volts max, and neither the caps nor the regulator will handle that.

It's remarkable that that controller worked at 56 volts at all.

As for which controller - I like the Phaserunner; it's very versatile, handles a lot of power and is fairly small. But it's not cheap.

 

[markz]

Which controller can I buy to get my build working?

Go ahead and just buy a generic controller from ebay seller hksunwin, very easy to hook up, very easy to modify the LVC from stock, plus there is an entire thread on that sellers controllers. I myself have used one for a cpl yrs now, and its solid in stock form. Buy his 48V and the controllers internals will be good to atleast 60V.

You could also buy on Aliexpress from Greentime, EVFITTING or something similar is their store name.

Also, its good to have two controllers, two throttles, and a few other odds and ends for spares, like connectors, soldering iron, solder, wire, heat shrink.

 

[dustNbone]

Yeah normally a 52V battery will work just fine with a 48V controller, usually the only issue is the battery level indicator on the LCD is incorrect. Occasionally they'll complain of overvoltage, but they should not be damaged.

That is almost certainly a 36V controller, and a marginal one at that. I'd get in contact with the seller and demand a replacement because they sent you the wrong one. It's possible that it was mislabelled at the factory, and they weren't aware of the mistake, but ultimately they're responsible for what they sell.

 

[markz]

Oh I see, you got the display going on, then you need to find something suitable for that display.
BMS Battery will work with it
Greentime might because they have display's but do confirm.

 

[amberwolf]

The LM317T is a regulator that can handle a max input of 41.5 volts, so you _might_ get away with a 36V system (42V max battery voltage.) If it's a controller for 48 volts nominal that means it has to handle ~56 volts max, and neither the caps nor the regulator will handle that.

While it's true teh regulator wouldn't handle the input straight, common ebike controllers use them anyway, and those huge resistors are used to drop the voltage down to a range the LM317 can handle, with their resistance calculated based on the expected current draw of the LM317 at the specified voltage. It's been done this way for more than a decade, successfully, if inefficiently and with some risk.

In the last several years there have been more and more controllers that have an SMPS LVPS instead of the linear types, but the old way is still more common, especially in the cheapest of the cheap.


The 50v cap is also fine if it's connected to the input pin of the LM317, since it won't see anywhere near it's limit under normal use. However, it's placement right next to the resistors means a shortened lifespan from the heat given off. Those resistors, while not normally charred, are often discolored even in a normal-usage controller, not overvolted.



Regarding the OPs problem, I'd say this controller is probably defective; manufacturing mistake most likely, wrong components somewhere, for this unit's intended voltage, or more likely, incorrectly labelled (built for a lower voltage, so the resistors were too low a value, allowed too much current, and overheated and burned; possibly blowing up the LM317 in the process).

Regarding finding a compatible controller, anything that works on "48v" should work on "52v" as well; though it is possible it may have an LVC too low for a 52V pack, and may give an overvoltage error when the 52v pack is full (but not when it's half-full or so). if it's programmable, like it has an LCD with settings you can change, that may be correctable.

 

[ScooterMan101]

I am thinking the same thing, poor quality control on the controller.

Robert S

I would get a 9 fet or 12 fet controller ( you can get ones that are 36-72 volt )
And
A Cycle Analyst is always good.

A good 9 fet or 12 fet controller can be bought from places like ...

em3ev.com

Grin Technologies

Luna ?

or you can get a good sinewave controller from powervelocity.com ( in Sacramento California )
He does tend to like the larger controllers more, but he has had some 9 fet and 12 fet controllers in the past. with his Blue Tooth dongle or built into the controller, you can use your smartphone as your display and voltage and amperage settings.

Regarding the OPs problem, I'd say this controller is probably defective; manufacturing mistake most likely, wrong components somewhere, for this unit's intended voltage, or more likely, incorrectly labelled (built for a lower voltage, so the resistors were too low a value, allowed too much current, and overheated and burned; possibly blowing up the LM317 in the process).

 

[Robert S]

Thank you all so much for you help! It all makes sense now to me. I will follow your advise and post an update when I got my bike on the road

Robert