Help Diagnosing a faulty lifepo4

[amberwolf]

Ah, the way you stated the wattmeter info implied you already had it and had made measurements during the ride.


About the cable and programming thing: There's zero reason for you to do that, to make a pack that came with the scooter compatible with the scooter. In this case, it's not OSN's fault that the pack isn't sufficient--it's the company that sold the scooter, for not providing a pack that would run it well. Or if the pack came with the scooter from a separate manufacturer, then it's that manufacturer's fault (but it is still the problem of the people that sold it, as far as the customer (you) is concerned).


The most important info that you need to know about this pack isn't on the page (other than that it comes with a BMS capable of 30A discharge). The specs listed on the linked battery imply the cells have infinite discharge current ability, which isn't true. Since they dont' list what the actual cell capabilities are, it's safe to assume they're actually 1C cells, maybe 2C at best (if you don't mind a lot of sag). Especially since they only call them "powerful", which usually means a vendor either has no idea what cells they are or what they're capable of, or that they know how low-end they are and don't want to put that in writing anywhere.

However, OSN almost certainly knows exactly what the cells are and can do, so its' likely they simply don't want to admit how low-capability (or average, for this type of cell) they actually are. Instead they hype them up in a way that makes people assume they're better than they are, without actually lying to anyone about it.

Side note: the info about charging cut off voltage is incomplete; it doesnt' actually list the per-cell HVC.

Specifications
Model Number OSN-OS266-4812
Battery Chemicals LiFePo4 (Lithium Iron Phosphate)
Nominal Voltage 51.2V
Nominal Capacity 12Ah
Cell Inside LiFePO4 26650 CELL
Configuration 16S3P
BMS inside BMS-L16S3010-486
Standard Charging Current 2.4A
Continuous Discharging According to customers' requirement
Fully charged Voltage 58.4V(3.65V any single cell)
Charging Cut-off Voltage 62.4(any single cell)
Discharging Cut-off voltage 32V(2.0V any single cell)
Dimensions (L*W*H) 143x102x251mm
Weight 6.12kg
Working Temperature (Charging) 0°C ～45°C
Working Temperature (Discharging) -20°C ～55°C
Cycle Life 2000 times

 

[fechter]

Side note: the info about charging cut off voltage is incomplete; it doesnt' actually list the per-cell HVC.

It gets lost in the translation. 3.9V charge cutoff. This should be fine.

I'd be interested in exactly what the current draw numbers looked like. They do jump around a lot, but you can get a good idea during steady acceleration.

 

[ElectricBeam]

I have tested the current and observed a maximum draw of 117 amps during fast acceleration. The company says the controller should be programmed for 60 amps max. Since the controller runs hot, I am wondering if the controller is actually broken and drawing a phantom current, probably due to experiencing reverse polarity.

Update: The controller is drawing a sustained 45 amps at max cruising speed of 35+mph. Motor is running WAY to hot, and is to the point where it needs to rest after a 1/2 mile ride, with low power most of the time as not to damage the low power battery currently installed on it. The hot motor and wires going to it would explain the extra current.

 

[amberwolf]

I have tested the current and observed a maximum draw of 117 amps during fast acceleration. The company says the controller should be programmed for 60 amps max. Since the controller runs hot, I am wondering if the controller is actually broken and drawing a phantom current, probably due to experiencing reverse polarity.

Probably not--you'd said this was a 100A system, and 10-20% over that for a momentary spike wouldn't be unusual.

If it's 117A continuously the whole acceleration (several seconds+), that's another story, and probably means the controller is either not programmed correctly or it's shunt (or associated electronics) isn't reporting the actual current to the MCU, or similar problem.

The latter problem *could* happen if the shunt was overheated at some point enough to cause solder on the PCB to run up the shunts and blob on them causing decreased resistance, making the controller think that it's drawing less current than it actually is.


It's also possible that the input capacitors could be damaged (from the reverse connection), and allow too much ripple current, which would heat the controller up inside. I'm not sure what effect, if any, that would have on the motor or wires between motor and wires.

Update: The controller is drawing a sustained 45 amps at max cruising speed of 35+mph. Motor is running WAY to hot, and is to the point where it needs to rest after a 1/2 mile ride, with low power most of the time as not to damage the low power battery currently installed on it.

The power draw from the battery at 45A is in the 2kW range, which is in the ballpark for 35+MPH. So it doesn't sound like it's more than it should be.

Motor running hot could be perfectly normal for that scooter at those speeds; "way too hot" isn't sufficient info to say if it could be a problem. Even if it's too hot to keep your hand on, it may not be anywhere near too hot for operation.

Do you have access to an IR temperature gun? Even the cheap ones at Harbor Freight and the like would be good enough for this. You can use this to measure the case and axle temperatures of the motor, at any point in a ride. I'd stop and check it after minutes at a particular speed, if possible, to allow time for the heat to soak thru the motor and out of it's casing, then stop and wait a minute for the casing to finish heating with no airflow over it.



Another thing to keep in mind is that stopping and starting repeatedly will heat the motor and system becuase low speed high load makes much more waste heat from the motor than when it reaches it's natural cruising speed. You might not notice the heating for a few minutes or more, depending on the heatsoak time of the motor. At the point it feels hot from the stop/starts, you may already have been riding at speed for a bit, so it might seem like the speed is causing the heat, when it might not be.






But if you suspect a problem, here's something to check:

Have the wires ever been disconnected and reconnected between motor and controller?

If so, they might've been reconnected in the wrong order. Usually this results in a non-spinning motor, but there are combinations of halls and phase that can result in a smooth-running motor that takes way more current than it should. This often also results in the motor's unloaded speed being much higher than it should be.

The hot motor and wires going to it would explain the extra current.

[/quote]
Rather the reverse: The extra current would explain the hot motor and wires.

 

[ElectricBeam]

All that is good and well, the problem is that the company claims the controller is set at 30 amps continuous, 60 peak. I have however seen a video on youtube clearly showing the parameters set to what I am reading. Seems like something fishy is going on. What I want know is how on earth the low power battery they are sending with these units is supporting that kind of power draw reliably for most customers. Also, when i was talking about the motor running hot, I was saying it would explain where excess current that is not being used is going. Is it possible the controller Is broken from my abuse, and is running the motor hot? The motor is rated 2kw, but like you said, it is possible it may be rated for high temperature operation.

 

[amberwolf]

All that is good and well, the problem is that the company claims the controller is set at 30 amps continuous, 60 peak.

Ah. Well, then it isn't a 100A system and they shouldn't say that it is--that's straight up false advertisement and lying. Not that this surprises me in the least.

As to what it's actually set to...most typical controllers don't have a separate continous and peak setting. I doubt theirs does either. there's usually just a single current setting, at which point the controller begins to limit current if it exceeds that for more than a very very short time (less than a second), to prevent damage to the electronics of the controller itself, primarily. Secondarily, the limit can be set lower than that to prevent damage to battery or motor, or to otherwise limit capability of the system.

But it's still only a single limit, not separate ones for continuous and peak.

There are advanced controllers that are (much) more expensive that may have these capabilities, but I don't expect they'd be using them on a scooter that's been cheaped out on it's battery (which is the heart of the system; if the battery can't handle the power delivery, it doesn't matter how good any other part of the system is).

I have however seen a video on youtube clearly showing the parameters set to what I am reading. Seems like something fishy is going on.

I'd agree with that. I'd also say that it isn't that unusual for this type of vehicle where the marketing claims are unrealistic, and/or the accounting decisions overrode the engineering ones but marketing decided to say it is still what it was designed to be.

There can also be changes in a product line where what was originally shipped changes throughout a run, or in subsequent runs, and cheaper and cheaper stuff gets used, or mismatched stuff. Then you get "support" departments that have no idea what's actually on any particular scooter or bike, because different stuff was used on different scooters in the same product model.

BTW, posting links to specific info you find could be helpful to others helping you, so anytime you have a specific source for information, like a video, or a product webpage, etc., it'd be good to include that in your post. Quoting the actual page info is also helpful, in case they change the info later or the page goes away or is inaccessible for whatever reason.

What I want know is how on earth the low power battery they are sending with these units is supporting that kind of power draw reliably for most customers.

It probably isn't. They may just not be complaining about it, or maybe they don't know what to expect so when it doesn't work very long or have as much range, etc., they either just live with it, or give up on it, or sell it to someone else, or even return it.

The company would never admit they have a problem; they'll always say that no one else but you have an issue, and wherever possible try to blame it on you. That's the nature of most of these businesses. They may even go so far as to make sure all bad reviews or problem reports anywhere get deleted, if they can bribe or coerce someone to do that. We've seen it here on ES with Luna and Lyen, for instance. Sometimes it works and sometimes it doesn't.

Also, when i was talking about the motor running hot, I was saying it would explain where excess current that is not being used is going.

Well, any current drawn from the battery is actually being used somewhere. What I think you mean is that it's just not being used for work that makes motion, and may be turning right into heat instead.

Since the speed you're going takes about the same amount of power that's being drawn from the battery, I don't think the heat is from wasted current though. (no more than the usual efficiency losses).

Is it possible the controller Is broken from my abuse, and is running the motor hot? The motor is rated 2kw, but like you said, it is possible it may be rated for high temperature operation.

As I noted in the previous reply, the shunt or input capacitors *could* have been compromised, but it's not very likely.

You can open up the controller and examine them; most of the time capacitor damage is obvious (swelling, leakage, exploded cans, etc). Shunt issues would be visible too, in that you'd see solder bridges at the ends or along them, or blobs along their length, etc.

If you're not sure what you're looking for you can take good sharp well-lit close ups of those areas, attach them to the reply, and we can look at them and see if antyhing is visible.


It's also possible FETs could be damaged, but those would usually just burn up and fail shorted, then explode the next time power is applied if they didn't already during the initial reverse incident.

 

[ElectricBeam]

I don't see why I shouldn't open up the controller and have a look tommorow. About the controller. It is a BAC-0501 from golden motor, Specs claim it can take 50 amps continuously, and 100 amps max. It can be seen at this link https://www.goldenmotor.com/frame-controllers.htm under the controllers section. The progming interface for it does actually show a max and constant currrnt, though the max may be fake or unconfigurable. The reason the setting are low is because this is actually taken from the smaller version of this controller.

You were mentioing a cover up of bad reviews by Luna? I knew Eric had a history with endless sphere but I didn't know it involved that. I actually know Eric, and was considering buying a replacement battery for the scooter from them. Can you tell me more?

 

[amberwolf]

Only that you can search for threads that either have a topic title with the word, or posts with the word, and find some that have had their OP self-delete or self-edit the problems away. There's implications in some that the OP wouldn't have had their problem fixed until they did this.

AFAICR, we've only seen this type of self-editing/deletion happen with a limited number of specific vendors/manufacturers. There are, of course, members that just delete *all* their stuff in hissy-fits and the like, but that's not what happens in these cases; it's just the specific problem thread. (sometimes that might be the only thread the OP has, but it doesn't appear to be the reason they did it).


Whether Eric had anything to do with that I don't know, only that the threads exist and were self-edited by their original poster, not someone else. And that there's no normal reason to do that, even if the problem was resolved, because someone else might have benefited from the issues raised and results that occured, if the information had been left in place.

I believe that the post history feature should allow you to view the original as well as the edited posts, and decide for yourself what might have occured and why.

One example of a self-deleted problem thread:
https://endless-sphere.com/forums/viewtopic.php?f=14&t=83781
I poked around for a few minutes but didn't see the others, however I know at least one member (etrike) was completely deleted in relation to posting Luna products (I don't know the details; none of his posts exist anymore so I can't go look to find out), and it's possible some of the threads I'm recalling were removed or remanded to the hidden moderator area because of the incessant arguments and trolling (bordering on flame wars) that popped up whenever Luna came up for a while. I don't have access anymore so can't check that.

For Lyen, I know that he has asked moderators (and been refused) to remove posts and threads that were negative about his products/etc. AFAICS he eventually stopped posting here, though if you look at his profile he still logs in.

There have been others over the years, mostly companies with already bad reputations complaining about members' reviews or troubleshooting posts. Some of those were messages to moderators, some were public posts. I dont' recall any specific ones ATM. The other two above only stand out because I had respected them for the most part until I saw that and other things happening.

 

[amberwolf]

Regarding the GM controller, I don't have any experience with that type; they may be more advanced than the typical ones seen on scooters and ebikes. I've read threads about them in the past, but dont' recall anything specific other than the BAC series in general isn't laid out like a common controller in an extruded aluminum case with wires out one or both ends, but has it's own custom-molded one with no cabling built in, just connectors on the face.


FWIW, a controller that is only 50A continous isn't a 100A controller, so they definitely shouldn't be claiming the scooter has a 100A system. (especially since the battery can't support that either).


It's probably not helpful, but:

There's some posts about the BAC series here on ES, but because that acronym is a part of many common words it's difficult to create a search to show only the relevant ones. BAC 501 finds nothing because the hyphen in the actual posted data isn't present (and the search engine wont' allow searches *for* hyphens because it's a modifier to the search itself). BAC-501 can't be used because the hyphen causes it to return zero results. Similarly, BAC*501 returns hundreds of thousands of results. 501 on it's own returns even more than just BAC. BAC* finds tens of thousands of posts becasue ti's part of too many words. Etc.

by post
https://endless-sphere.com/forums/search.php?keywords=BAC&terms=all&author=&sc=1&sf=all&sk=t&sd=d&sr=posts&st=0&ch=300&t=0&submit=Search

and this by topic
https://endless-sphere.com/forums/search.php?keywords=BAC&terms=all&author=&sc=1&sf=all&sk=t&sd=d&sr=topics&st=0&ch=300&t=0&submit=Search

 

[999zip999]

Not much info in that battery link.

 

[ElectricBeam]

Was going to test the temperature the motor got to but dumped that idea once I realized the heat damage on the positive terminal had gotten worse. I should have mentioned this earlier, but basically ever since I got the scooter the positive battery terminal on the controller has been heating up to a degree where the screw and metal clip over the terminal have welded themselves together. Not sure if this is actually tied to the rest of the situation, but thought this was worth mentioning now that I have it open. It would appear this is due to too much current going through the connector, but it may be because between the positive ring terminal and the terminal block, there is a auxiliary ring terminal, which all the power flows through, and maybe this is enough resistance to cause the problem. It has even melted the solder where the block connects to the PCB, making the connection weak(on top connection right of the middle, a hole in the solder where the contact for the terminal block is can be observed). After posting this I resoldered it. But since there is no damage to the board, I don't think this is the origin of the heat. The rest of the PCB looks ok, albeit a little sloppy, particularly one bridge which was is clearly just a hand soldered blob. It has even touched the capacitor next to it, and burned it a little, but otherwise it looks ok. here is a picture of the top of the PCB
And here is one of the bottom
Zip mentioned a lack of information on the battery page, and I first thought it might be because that post is more of a general product showcase then a specific product, but looking, back, even the specific products have very little information for a supplier direct product. This one doesn't even mention anything about the cells inside. https://osn.en.alibaba.com/product/...ricycle_scooter_48V_20ah_Lifepo4_battery.html

This is off topic but hilarious. While on OSN's alibaba page, there is an advert for an Lifepo4 18650 they make which can supposedly do 40c. what do you think of that claim? https://osn.en.alibaba.com/product/...ry_for_electric_tool_and_starter_battery.html

 

[amberwolf]

Was going to test the temperature the motor got to but dumped that idea once I realized the heat damage on the positive terminal had gotten worse. I should have mentioned this earlier, but basically ever since I got the scooter the positive battery terminal on the controller has been heating up to a degree where the screw and metal clip over the terminal have welded themselves together.

This means the connection is poor, so the resistance is high, and power is dissipated as heat at the terminal instead of passing thru it to it's intended destination.

Why the connection was poor to start with could be that the controller's terminal wasn't properly soldered to the controller itself, or it could be that the screw wasnt' properly tightned into the terminal, or the ring terminal was deformed during crimping and so it never allowed teh screw to seat correctly (tightne screw, ring deforms more to flat, now screw is loose), etc.

I'd recommend replacing the terminal block on the controller, or at least removing the existing damaged one and replacing it with some other connector (even if it's just another new screw terminal). Same with the ring terminals on any wire that goes to it.

Otherwise you will continue to have a high resistance there, and continue to have heating there, and power loss, and voltage drop, and all the problems these create. You might even have a fire in the wiring.




Regarding mentioning issues, whenever you have any problem that you're troubleshooting, it's a really good idea to note down *everything* that is unusual *in any way* even if it has nothing to do with the problem being troubleshot--because it could actually be a part of the problem indirectly, or even the root cause.

It's sometimes quite frustrating to be helping someone and not be able to find a definitive cause for a problem, and then suddenly have another symptom sprung on you that was actually known to be there all along but never mentioned. :/




In this case, such a high resistnace point in the battery to controller circuit will cause a voltage drop under load.

That means there will be less voltage avialable for the motor to use, so it won't reach full speed that's possible otherwise (assuming no speed limiting in the controller).

If the voltage of the battery is already low, near the controller's LVC when under load, then this extra voltage drop means the controller might not see enough to stay over LVC, and it can shutdown when any load is applied (even though the battery itself and it's BMS have not run empty and shutdown).

Zip mentioned a lack of information on the battery page, and I first thought it might be because that post is more of a general product showcase then a specific product, but looking, back, even the specific products have very little information for a supplier direct product. This one doesn't even mention anything about the cells inside. https://osn.en.alibaba.com/product/...ricycle_scooter_48V_20ah_Lifepo4_battery.html

Not surprising at all. If they said what was in it, they'd have to make them all with the same thing, and have to make sure they honor the same specs all the time. It's easier if they can just use whatever they've got that makes a pack of that capacity and voltage--even if it doesn't have the same performance as other packs (better or worse).

This is off topic but hilarious. While on OSN's alibaba page, there is an advert for an Lifepo4 18650 they make which can supposedly do 40c. what do you think of that claim? https://osn.en.alibaba.com/product/...ry_for_electric_tool_and_starter_battery.html

If they were actual A123 pouch cells, they could probably do that. I don't know if A123 can cells can do that (same as were used in the original DeWalt tool packs).

Whether any of the other LFP cells out there can actually handle that, I don't know. OSN did at one time sell scrapped A123 pouch cells as new (I think they were ones that were supposed to have been destroyed and recycled for materials, but you'd have to search around ES and/or google to find the real story on that part). I don't know if they ever had scrapped A123 can cells.


But if those are supposed to be 40C cells, why do they use 15C in the URL, and say 20C in the short description next to the image? And later in the specs they say 20-40C continous, which isn't a rating, it's a marketing lie. Either they do only 20C, or they do 40C. If they *might* do anything in between, it's not a valid spec.

I'd venture you'd be lucky to get 1C out of them without sag, and 2C would probably , and charging them at their "2C" rate would probably shorten their life, or worse.

Seeing things like that combined with everything else seen on their site and what they've said as support info is when you can say with fair certainty that they are just making up numbers to sell things, and that you can't trust anything at all that they say about any product they have, make, or sell, no matter what it is. Maybe it's true, maybe it's not, but you have no way to tell without buying first and doing your own tests.

If they *really* had good batteries, they'd have all sorts of charge/discharge curve charts along with their exact testing methodology, etc., like "real" battery companies do (Samsung, panasonic, etc).

Even if companies like OSN make their own cells and don't just get containerloads of someone else's recycled trash to rebrand (look up anything with *fire in the name), there's nothing they provide to show that they or their products can be trusted to be reliable or consistent.

 

[999zip999]

I think osn buys odd lots of what they can get there hands on the time. Like one time they where selling A123 38650 or some odd A123 with screw tops 10ah and 30c or so. Just some small left over lot. Plus didn't Archimedes buy some A123 20ah pouches for 35.00 plus shipping.. They also made some junk not working packs to. So there other vendors that are less a gamble.

 

[ElectricBeam]

Ok, Ill note down everything that might be helpful in this post.

1) A loud metalic hum/vibration when starting acceleration from 0. Think mix between amplified chain noise and creaking. Always assumed it was just the startup of the very powerful motor. This has happeded since day 1

2)The first battery I had in this scooter actually worked, but i sent it back. I now realize I was just seeing the poor battery sag low under high stress. I exchanged it for the current battery this thread is about. (Further testing has revealed it will if you pin the throttle for more than a second. It appears as though the controller really is taking 100 amps for more than just a split second)

3) Even though the 12ah 48volt lifepo4 battery I have in the scooter now is rated for nowhere near the same current level as this scooter, The BMS doesn't cut off even where the other battery would, albeit with profuse voltage sag. I don't know who manufactures this battery, or if it even has a BMS

3)I believe the motor on this scooter is just a BLDC-108 from golden motor with a redesigned can shaped case so it can fit in this scooter. It can be found along with the recommended controller pairing(the same one in my scooter) at the bottom of this page. https://www.goldenmotor.com/ This seems to imply the motor is rated for this controller,even at full power. Here is a performance chart.

4)This youtuber is somewhat affiliated with the company, but does have detailed videos about the scooter I have, the super lithium 1500.
This is where I saw the setting the controller was set to, and he also claims a range of nearly 30miles at 30mph,
which seems very high considering the current draw I have observed. https://www.youtube.com/channel/UCMASzMeiFQZZT2xCMi1WXLA

5)the scooter is fused for 100 amps yet the fuse hasn't blown or melted, and the scooter is mainly run with 12 gauge wire. The phase wires to the motor are maybe 15 gauge.

6)If I think of anything else I will post it. If you wan't to know something I haven't mentioned, I will do my best to find the answer.

About the connector with a high resistance. I spent some time cleaning up the contact and ditched the ring connector in favor of a direct connection to my watt meter. This seems to have eliminated the problem, as the contact doesn't even get warm now, albeit the controller is in open air. The problem must be where the wire connects to the ring terminal, and maybe also the fact that the main power ring was stacked on top of the auxiliary one, meaning the current had to flow through an extra layer of resistance before entering the controller.

Well anyways, I am not sure exactly how to proceed now, And everything so far seems to point out that the problem is simply a bad battery and controller match.

Hope this helps.


Edit: After the longest ride I was willing to do with the small battery currently installed (maybe 2 miles), I tested the temperature of key components with a thermal gun.
My motor reached 110, and the cables going to it about 88, and the controller reached 98. These numbers alone don't seem to alarming, but the motor feels way hotter than the controller despite the relatively small temperature difference. Perhaps the reflactive metal motor case is interfering with the reading. The Terminal just won't heat up above ambient, so the connection is much better now.

 

[fechter]

I guess it would be good to recap exactly what's going on at this point. The controller terminal was obviously overheated by a bad connection and it appears you fixed that.

Is the controller still cutting out?

Do you know what the current draw actually is when running?

One possibility is the hall/phase match is incorrect, which would make the controller draw much more current than normal, this would also give you the loud noise on startup. The key is to measure the actual current when running. A no load (wheel off the ground) test at full throttle would tell.

 

[ElectricBeam]

Yes, to recap, it appears as though the current problem stopping the scooter from working as intended is a battery who's BMS is cutting out due to overload. The battery does sag to 46 volts before cutting out, achieved by pulling the break well the scooter is up off the ground and at full power, and well I can't say for sure that the same thing is happening when the scooter is being ridden, it seems to be the exactly the same mechanism.


The company claims the controller comes set at a current that matches the battery, which would in theory fix the problem. I have seen a video on line which appears to show the controller set at full power stock. The link to the channel is posted in a previous response, and I might add it to this post once I'm back to working on a computer. I have measured the current the scooter is drawing with an inline watt meter, and have observed a long lasting peak of 117 amps or 4kw with the 48 volt battery installed, and 45 amps to maintain 35 mph with a 170 pound rider, a nearly perfect match for the BAC 0501 controller's rating. The controller can be programmed, but I have not purchased the expensive cable needed to do so.


The scooter's acceleration is very high, which would suggest most of the power is being turned into motion, however the motor does reach over 100 degrees with even a short, light ride, and feels even hotter than that reading, while the controller reaches 100 degrees and the phase wires are very warm.
Amber has suggested that the sealed motor could be rated for this, and from my personal experience, many of these compact scooter motors run hot, likely due to lower efficiency and poor cooling. This particular motor is rated for greater than 85% efficiency, far from great.

The charring of the positive battery connection appears to have been caused by a poor crimp connection at the base of the ring terminal that was screwed into the block. All the testing I have done has been withthe battery that was in the scooter for a smaller one from a weaker scooter from the same company. The voltage will sag far down and the bms will cut off if the controller is given full throttle for more than an instant, suggesting the controller dress over 100 amps until it reaches full speed. But keep in mind this is a weak Lifepo4 battery.


I will test the current when the scooter if off the ground in an hour or so when I get home, and post it here.


I have wondered about just removing all the main electronics except the motor, and replacing them with a high quality 48 or 72 volt battery from lunacycle, and either using the same controller, or one rated for 72 volts with the same hall configuration to eliminate the problem while improving the system at the same time.


What are your thoughts? Also, thank your for all the help you guys have given me.

Edit: Unloaded, the motor draws 6.4 amps at 53.4 volts.

 

[fechter]

The no load current sounds about right, so it seems the controller is working properly. It seems the cells are just sagging too much under load. If you reprogrammed the controller for a lower current limit, you could probably keep it from tripping, at least while the pack is full. This would mean significantly slower acceleration but top speed would be the same.

The fact that the motor heats up so quickly would be another indication that maybe the controller current limit is set too high. At a lower setting, the heating will be less.

Of course once you've used it at a higher current, it's no fun to downgrade the power. A new pack with a higher rating would be ideal, but pretty expensive. 100A burst is quite a bit so you would want something with 25-30Ahr to keep the C rate reasonable. If you go to a higher voltage, the pack would still need the same current rating, so would be larger and more expensive and you'd be able to drain it faster with the higher top speed. All this might be too much for the motor.

 

[ElectricBeam]

I think that is exactly what is going on, and the only way to keep the power level at the thrilling amount it is at now is to replace the battery, which I am willing to do. Yeah, the motor runs a little hot, but you are absolutely right about not being able to go back once you have experienced real performance. I many also look into cooling the motor in the future. I am looking at lunacycle's batteries, and many of their triangle packs can handle the current needs this setup has. This 52volt pack is 14s7p, and made of panasonic GA cells, which boast a continuous 10amp discharge. The BMS is 50amps continuous, 70maximum with the whole unit able to peak at 93amps, Which i think is close enough, and nothing a little programming of the controller can't fix. https://lunacycle.com/triangle-52v-panasonic-ga-18650-24ah-pack-high-power-long-range/ I could also use a 72 volt pack like this https://lunacycle.com/72v-triangle-panasonic-ga-17-5ah-with-luna-charger-ebike-battery/, but would have to get a new controller, and replace all the accessories, but it would appear as thought the scooter would gain 5mph. May be worth it.