Known Issues & Problems with Rad Power Products + Help, Solutions & Fixes

[nitwitticism]

Hello, EBR forum—First up, thanks to all of you. Really benefitted from all the smarts here as I got serious about my first e-bike purchase this year. Hopeful you might be able to steer a little of that savvy my way to help me understand how to solve this particular challenge I'm having with my recently purchased and upgraded Rad Runner +.

Long story short, I implemented the 32a controller (via Electro Bike World: https://electrobikeworld.com/products/35a-controller-rad) and the matching display (https://electrobikeworld.com/products/kt-lcd8h-color-for-rad), and after initial concern about downtube connector pins getting compromised, have it working regularly. I've modified the settings a few times due to the problem I'll describe below, alternating between the guidance from Bolton (https://boltonebikes.reamaze.com/kb/radpower-upgrades/how-do-i-program-my-radpower-upgrade and

), from YouTuber SuPRCooPR (

), and most recently from Sideburn Studios (

), paying especially close attention to C5 and C14 attributes that I thought may be the path to solving my recurring battery issue.

The issue is that the battery cuts out regularly on hills, where anywhere between P3-P5 when exceeding 4770 watts of motor power (MOTOR W in the display)—typically a hill climb for me—the battery abruptly shuts off all power to the bike and will not recover without a charge.

What am I overlooking in my controller settings that can curb this issue?

I'm aware that what I'm probably experiencing is that the engine is no underpowered compared to the controller, and the battery's BMS is stepping in to present a bigger problem.

I didn't modify the Rad Runner Plus lightly. My issue is I live in a hilly terrain, rife with (according to Hill Attack app) 126% hills and lengthy rises, and have been trying to get my bike into commute-worthy shape for the hills it'll need to tackle. Right now, I can probably barely pull that off, staying close to the lower gears, but I'm being careful and meanwhile know that I don't have a safeguard in place to stop the Battery Management System from cutting off the bike's power at any given moment. (Incidentally, while the battery ceases to function, it only requires an hour or less of charging after a full charge and experiencing such a cut-out. I'm also concerned this is 'training' the battery poorly or potentially doing damage to it as I try to get to a better resolution.)

I've contacted Electro Bike World and yet to receive any reply.

 

[BKing]

Since it won’t turn back on after the cutout issue and requires charging an already mostly charged battery it definitely sounds like a bad BMS inside the battery or you are exceeding the design of it. Does it only cutout after going up a few hills and getting hotter?

 

[nitwitticism]

Correct @BKing. It seems closely tied to Motor Power wattage tripping the BMS, and I only get to the 5k mark with a serious hill.

Unfortunately, my neighborhood is lousy with these steep hills!

What's unclear to me is whether it's normal for a Rad Runner Plus with a stock battery to be able to comfortably exceed 5k watts.

Would love an answer to that from Rad, whom I've contacted also to better appreciate where to best address this issue.

 

[AHicks]

4500w (if that's what you are actually pulling?), is WAY in excess of your battery's capacity. By a factor of at least 2, maybe 3. It would be no surprise here to hear it's shutting you down.

I have a '17 Rad City, which uses pretty much the same battery you have. I have replaced the OEM direct drive motor with a MAC 12t geared hub motor, which is conservatively rated at 1000w+. I have a 35a (max) KT controller that I've limited to about 2000w - out of concern for the wire size used internally within the battery (yes, I've had it apart). It's only 14 or 16ga, I don't remember which for sure. In any case, there isn't a wire anywhere on that bike capable of handling the kind of power your talking about.

If you continue pulling/trying to pull huge wattage like that, I can almost guarantee you're getting "stuff" REALLY hot. It's just going to be a matter of time until you let the smoke out of something....

Figure 4500w, at 50 volts (average battery charge voltage) is about 90 amps.....

 

[nitwitticism]

I hear you, @AHicks. The question at hand: So what should be done about this?

Is there a maximum wattage controller setting I should be implementing, or are you unaware of the particulars of this controller? I certainly have hunted for this answer but haven't found it yet. I thought the controller, as the 'brains' of the bike, would be the place to solve for this but perhaps there are different approaches across battery, motor and controller that would make sense. I'm really not interested in becoming an extremely-amateur bike modder, but this is where I'm at.

I'm merely trying to climb these hills and have no interest in working my bike's components beyond their functional capabilities.

 

[BKing]

If your display shows wattage that high it’s not working right because you can’t get 5000 watts from your setup. Need to start with the basics, what tire size is your bike, 2.3in wide or 4in? If 2.3 it’s like the Radcity and should be at least 60psi. Lower pressures affect performance greatly for heavier riders. Even with correct tire pressure and if you are a larger person, like over 220 lbs you can’t get up really steep hills unless you get a running start downhill first. I’m down to 220 now and have the 35A Bolton controller with stock motor on a Radcity. It’s much better climbing average hills but I don’t push it for very long uphill because something might blow especially when under 10mph. I do ride around 400 watts for an hour or two including using the throttle on many starts and accelerating out of sharp turns on flat terrain averaging 19mph. The stock motor is really hot when I get home. I’ve been doing that for many months and no problems yet.

 

[nitwitticism]

@BKing, thank you for the clarity that this number is in itself inaccurate! Very helpful to know that about my setup.

To your question, this new 2021-issued RR+ is using the stock Kenda K-Rad 20" x 3.3" tires, which I've set to 23 to offset another setting per this user's approach:

. It's also the stock Bafang-for-Rad engine.

I'll check the psi today, was planning to do that already.

I'm at 250 lbs, so trying to be very mindful of the basic physics in play and what's feasible here! That's been top of mind throughout this process of diagnosing the cut-out issue.

I've not been hand-checking engine or controller temp as it's felt to have been a moot point with the cut-outs happening as predictably as they are. But if my watts are not accurate, there is something more fundamentally askew with my configuration that I need to get right.

 

[AHicks]

Confirm the max wattage you are pulling (tire PSI might have a little to do with it, but not when talking the 4500 you're claiming). 4500w seems WAY high.

Then use C5 to reduce max wattage as necessary. Example: While full available power is C5=10, you can use C5= 03 to cut whatever your max reading is by 1/2.

Once you get that close to something you can live with, you can use C14 to fine tune the wattage being used in PAS 1 for example. My "target" wattage for PAS 1 will be in the area of 80-150 watts for good low speed handling and compromise between assist and exercise.

 

[nitwitticism]

@AHicks, if tire PSI is likely a minimal factor, what's the surest path to confirming the max wattage?

I'm not sure why this would be such a task given the relatively simple state of my bike: stock RR+ with the seemingly ubiquitous 32a controller (https://electrobikeworld.com/products/35a-controller-rad).

This seems like good guidance, really appreciate your perspective. Thanks again.

 

[AHicks]

@AHicks, if tire PSI is likely a minimal factor, what's the surest path to confirming the max wattage?

I'm not sure why this would be such a task given the relatively simple state of my bike: stock RR+ with the seemingly ubiquitous 32a controller (https://electrobikeworld.com/products/35a-controller-rad).

This seems like good guidance, really appreciate your perspective. Thanks again.

It's just a matter of getting on it and pointing the bike at one of your big hills. Give it full power and watch the watt meter climb, but don't let it get up into the exotic numbers. If it climbs above 2500w or so, shut it down and finish your ride while limiting power to no more than say 1000w.

If you have to shut it down as it climbs through 2500w, when you get home, it'll be time to get on the phone or start firing off emails asking you sellers (elektrobikeworld) about your experience. Something isn't working properly.....and I don't think it's got anything to do with improperly set parameters.....

I'm staying positive though. My bet is you aren't going to see 2000w on your ride. More likely something less than that. We'll see. Let us know.

 

[BKing]

You mentioned the bike was newer so I assume under warranty. If so you need to put the original controller and original display back on it. Then if the problem is still there you can get a battery under warranty. They won’t give you any warranty on anything related to your problem if you have the kit on it.

 

[AHicks]

You mentioned the bike was newer so I assume under warranty. If so you need to put the original controller and original display back on it. Then if the problem is still there you can get a battery under warranty. They won’t give you any warranty on anything related to your problem if you TELL THEM YOU have the kit on it.

You stay with RAD warranty for things like you battery, frame and motor. For controller and display issues, you don't call Rad, you call Electro Bike World.

 

[BKing]

You stay with RAD warranty for things like you battery, frame and motor. For controller and display issues, you don't call Rad, you call Electro Bike World.

They required pictures and/or videos on all warranty issues I had. I don’t think he will get any help from Electro bike world when the problem appears to be battery related because it requires a charge to wake it up after a cut out episode.

 

[AHicks]

They required pictures and/or videos on all warranty issues I had. I don’t think he will get any help from Electro bike world when the problem appears to be battery related because it requires a charge to wake it up after a cut out episode.

Sorry, I was so focused on the big wattage I missed that comment, and you would have to be careful with any pictures that needed to be taken/supplied. It does sound like the state of charge could be an issue - but that's not what's causing these 4000w+ readings he's getting.

 

[nitwitticism]

Love your game plan, @AHicks.

Here's the update on what went down:

1. My PSI was low, around 10. I got it to 25 PSI (the spec calls for a range of 20-30 PSI). Good guidance, thank you!
2. I did not modify any controller settings yet.
3. I went up the steepest hill where I've been benchmarking the power cut-out events, sticking with P1. I assumed I would be fine as I've been able to climb the full hill once or twice by keeping it on P1.
4. I didn't max out the throttle, but do think the PSI change definitely impacted the max wattage #s downwards, bringing them to a lower level overall.
5. Instead, it cut out at 1370 watts, around the same location on the hill it has cut out previously.
6. This was at full battery, and I expect the battery will register as fully charged with an hour's charge (or less).

Where does this leave me in your mind? Should I not let motor power wattage climb above 1000w at all and try that? I could also start that process with C5, which is set to 10 for the moment.

I'm glad for the progress but feel as foggy as ever on the root cause.

I'm dedicated to figuring this out.

I do have a replacement wiring harness coming from Rad that would enable me to test whether I did damage one of the pins in that cable (when I was implementing the new controller) in a way that is impacting bike performance, but my suspicion is that this is an edge case and unlikely (as it would likely throw an error code on the display if that connections were unsound).

 

[AHicks]

If you look at the owner's manual, it will mention somewhere where they don't recommend the use of full power while climbing for any extended period of time (was it 2 minutes?). I think you can read that as them saying you can't use full power more than a few seconds.

Whatever, we're beyond a lot of that with the updated controller. It shouldn't have too much trouble at 1370 watts (1370w a MUCH more believable number by the way).

My suggestion would be to use the C5 parameter to lower that max 1370w you have now to 1000w and see what happens. Maybe try C5 = 05 (1370/1.33=1,030)?

How long is this hill? Can you climb it in a few seconds, or is it going to take several minutes?

 

[BKing]

Love your game plan, @AHicks.

Here's the update on what went down:

1. My PSI was low, around 10. I got it to 25 PSI (the spec calls for a range of 20-30 PSI). Good guidance, thank you!
2. I did not modify any controller settings yet.
3. I went up the steepest hill where I've been benchmarking the power cut-out events, sticking with P1. I assumed I would be fine as I've been able to climb the full hill once or twice by keeping it on P1.
4. I didn't max out the throttle, but do think the PSI change definitely impacted the max wattage #s downwards, bringing them to a lower level overall.
5. Instead, it cut out at 1370 watts, around the same location on the hill it has cut out previously.
6. This was at full battery, and I expect the battery will register as fully charged with an hour's charge (or less).

Where does this leave me in your mind? Should I not let motor power wattage climb above 1000w at all and try that? I could also start that process with C5, which is set to 10 for the moment.

I'm glad for the progress but feel as foggy as ever on the root cause.

I'm dedicated to figuring this out.

I do have a replacement wiring harness coming from Rad that would enable me to test whether I did damage one of the pins in that cable (when I was implementing the new controller) in a way that is impacting bike performance, but my suspicion is that this is an edge case and unlikely (as it would likely throw an error code on the display if that connections were unsound).

I’m thinking the Rad battery BMS has been changed to prevent using these stronger controllers. This way the batteries last longer especially during the warranty phase for them. They won’t tell you about the BMS, probably just the battery designer knows about it. Glad to hear your tire pressure helped. Even engineers on endless sphere don’t believe it.

 

[nitwitticism]

@BKing and @AHicks, I think there may be something to this theory.

So I received some guidance from Electro Bike World (C5 to 6, C12 to 0) and went out on P1 to the same hill with a fully charged battery. It only made it to 1260-1270 before kicking out again.

I'm going to raise this with Rad but expect I know what they'll say in response. Since it's clearly triggering the BMS (this happens to a fully charged battery each time), I wish there was another way to test whether it's defective in some way.

This hill is minutes long in terms of ascent, with some points where it eases off midway, but I'm not seeing improvement with these modified settings at all—if anything, it's getting worse in terms of performance. I have been pedaling little to not at all in part to make this a purer test, but I'm not sure if that might be playing into the issue in respect to some other controller setting.

My guess is Electro Bike World will next suggest I replace the battery entirely, which I was hoping to avoid, but I suppose you're in for a penny, in for a pound once you customize? Just want to get to a stable solution and put the safety issue to bed so I can get some miles on this otherwise wonderful machine before the winter hits!

 

[BKing]

Try C5 = 3
Leave C12 at zero.
It will be less power but hopefully in range of the unknown BMS firmware or the BMS’s problem.
I’m still saying to put the original controller back in. Then if it fails you can get a battery under warranty. If it does not fail you will have to wonder whether they limited that BMS on purpose or that it just fails under high load.

 

[nitwitticism]

Success on full hill climb at P1 with your recommended setting C5 setting, @BKing!! Cannot thank you enough for all of this.

Now, would I have been able to progress through P5 without issue?

I’m trying to sit and think what the takeaways are here given this new success. I’m going to try doing a trial commute soon to see if the hills I hit will be surmountable or not given my present physical abilities. Based on that, I think I will mull a complete custom battery upgrade.