Dynapack battery BMS wake up? Motocompacto battery dead

[100percentjake]

Hey guys. I have been working on adding a range extender in the form of a parallel battery on my Honda Motocompacto and goofed up and hooked it up in parallel without a balancer/balancing like an idiot. After a powercycle or two the internal battery in the Honda stopped outputting any voltage. Took it apart and I'm getting 38.12v across VG/VP but 0v out of the BMS itself. Nothing looks burned, I'm assuming the external battery just tried to pull a bunch of amps from the battery and it went into some sort of deep protect mode.

Found a few things on the board. Firstly, it talks to the controller/dashboard via Canbus. Pretty typical, potentially good news for aftermarket/DIY batteries. Found an unused header labeled J10 with pins 'pack-' and 'release'. Found another unpopulated header that appears to be... programming/JTAG header? 3.3V, SDWIO, SWCLK, REST, GND. Nothing obvious to reset the BMS.

A new battery is $321 (Honda Part number 08Z15-PR8-100R8) and I'm not entirely opposed to buying another one and sacrificing this battery to the DIY cause by putting an ANT BMS with CANBus in and seeing if I can make it work like OEM.

Any advice on getting this thing working again is welcome. The battery is a Dynapack model BL001.

 

[amberwolf]

Both the P 020-J that is circled in red, and the two 201 resisters are coated with heavy plastic. I had to puncture the plastic coating with an X-Acto knife to reach the solder, and I could detect small voltage on the side of the P 020-J pointing to the right, but not on the other side that points to V3.

Assuming that's a fuse, it probably means it's blown.

The "plastic" is usually conformal coating to keep humidity/etc out of the parts and the PCB; it probably glows with a UV light, and probably dissolves with acetone (qtip dipped in it and rubbed around an area, repeatedly until the light doesn't show much glow) or similar, if it's like the stuff I've typically encountered.

If there is no voltage on the main red wire, then I will probably punt, assuming that the red only becomes hot when the throttle is opened.

If red is the main battery output, and there isn't any other voltage source from it to the system, throttle wouldn't do anything if there's no voltage from the battery (unless the throttle has a switch in it to activate the system only upon usage...but taht would mean that at every throttle activation the entire system has to power up, reboot, then begin to respond to the throttle input, which by that time is probably above whatever the safety limit is for "stuck throttle" on the controller and then would fail to activate the system (it might not have such a limit, but they all should, in case of broken grounds or other throttle faults to prevent runaway operation).

It would also mean that the entire system would power off whenever you let the throttle rollback to zero. :/

 

[vintagegarage]

I took apart a second Motocompacto today. I initially had more than 30 volts on the red output lead from the battery in that one, but the voltage disappeared when I disconnected the other two black plugs. Plugging all the plugs back in, I was never able to duplicate that test, so that was a bit worrisome. In any event, I tried battery #1 in Motocompacto #2 and the battery wouldn't charge. Symptoms were the same for battery #1 in either Motocompacto, no charging, no going. I reconnected battery #2 to Motocompacto #2, and Motocompacto #2 still works fine. Took # 2 for a successful spin around the block. And while I didn't try battery #2 in Motocompacto #1, I concluded the #1 battery is fritzed.

 

[vintagegarage]

I'm just going to give up and order a new battery and wait for it to come in.. might be months. I assume others will have the same problem, as all I was doing was a range test. I also assume that at some point, Honda will have some sort of exchange program for the batteries if this is a common problem. So far, from what I know, it isn't a common problem though.

 

[100percentjake]

Sorry I forgot about this thread. If you take a look at your red wire coming off the pack, look at the huge trace that goes to it. That trace goes to the right to two FET packs, and then from there it goes to a rectangular surface mount device with three legs. This is the fuse, but it's not a normal fuse. It's a fuse that can be blown by either current or by the BMS intentionally triggering it. In my case, it is blown and it doesn't just result in an open circuit, it pulls stuff to ground (I think), so you can't simply bridge the legs of the fuse to bypass it, it would have to be removed and the two main terminals bridged from there.

TL;DR



Yes.

 

[vintagegarage]

Thanks. I appreciate the info very much. In any event, to get under the circuit board to see what is going on, I think I would have to unsolder all the battery packs. Is that what you did? I think that is more than I will do for now and do that only as a last resort.
I don't know if Honda will want the old battery, but I will go over there this morning, and order a new battery. Batteries are backordered, perhaps forever. I don't know of an alternative source for a battery, so I may try to repair this one as a last resort if a new one never comes in.
I think the BMS intentionally blew the fuse, but I am not sure why. I don't think it was an overload condition, as I was starting my last lap of the range test with 7% battery, after about a 3 minute stop at a stop sign to record data, and was going down a very slight hill when everything shut off. The last reading of the app before Bluetooth and the dashboard and lights shut down was this;


I was also able to get the last battery health reading that the app saved, even though Bluetooth has crashed. I do not know if that battery temp is normal at the end of a 10 mile ride, or if it is too high:


The range test I was doing was similar to the Mode 1 range test I did the day before. In the Mode 1 video, I got a normal shutdown at 5% as expected. Bluetooth, dashboard, and lights all stayed running while I walked the Motocompacto home. I didn't get a battery health screen print on that test unfortunately. The battery charged back overnight to 100% after the Mode 1 test. This is the Mode 1 test, sorry it is "Old and Slow", but the pace of the video picks up after the first lap:

 

[vintagegarage]

For what it's worth, here is the log from my successful Mode 1 test, followed by the log from my Mode 2 test that ended in failure. On the Mode 2 test, the dashboard went from 2 bars to flashing 1 bar in only one lap. I started the last lap at 8% battery, with a flashing 1 bar on the dashboard:

 

[100percentjake]

Batteries are backordered, perhaps forever.

Oh. Crap.

 

[DaLanMan]

Thoughts and musings....
first off, when it comes to Honda, who you talk to has a lot to do with your odds of success. Differing dealers and so forth in the bike world have better in-roads with the mothership. My fav mechanic worked on my Honda, but would not order parts. Why? he was not friendly with the ordering system and just hated having to deal with politics to get parts. I eventually just started taking the car to the local big Honda shop, paying them 15 bucks for "analysis" giving them the list of parts that my guy had and walking out with what I needed. They had good connections and I have ordered parts from them late last year (10 years after I sold the CBR) and got parts from them, shipped up to Norcal when everyone up here said "parts are not available"

So, look for the biggest Honda dealership you can find, call their parts counter and explain the problem. They often will help out if you are doing a weird thing...

WHich brings me to the other musings.. That beast does give all new meaning to the term "box bike"

And lastly... there is a guy here in Cali trying to sell one of those things that is still in the factory shipper (I assume he got it delivered on a foam pallet thing) he is actually asking for exactly what he paid for it which he has so far not gotten. I pinged him and pointed out that I have seen his ad like 12x and it might help if he stopped using the Honda name and pointed out "electric bike" Because I had no idea wth a motocompacto was until this thread...

 

[vintagegarage]

I have a very good relationship with my local Honda dealer. They always treat me right. Next door to the Honda car dealer is the Honda Powersports dealer, and both have the same owner. Motocompactos are my first experience with working with the car side, but I bought 8 Honda Motorcycles from the Powersports side in the last four years. I bought four Motocompactos from the car side, two in November, one more in December, and the fourth at the end of February. The Parts Manager on the car side put in a priority order this morning to try to get me a Motocompacto battery. The Service Manager has also been helpful in giving me the green light to see what I can find and is interested in helping me understand the circuitry. I started working up the YouTube video today of the Mode 2 range test, and at the end I take apart the battery and include the photos and information I found in this thread. I appreciate everyone's help here. It will take me another day or two to edit and post the video, but it ends with me ordering a new battery. The main part of the Mode 2 video is almost identical to the Mode 1 video, except the battery drains faster as you would expect, as the speed is about 5 mph faster in Mode 2. The Mode 1 test ends normally with the battery at 5% and all systems still alive. The Mode 2 test ends abnormally with a hard shutdown.

 

[DaLanMan]

Well bugger, I was hoping your battery solution would be just finding a parts guy with juice.

I am not super clear on this vehicle, like I said never heard about it til this thread. I am surprised Honda is not supporting it. I ran across the first "out of service contract" part while trying to fix a trans on a 98 Accord. Honda actually had stopped dealing with them... I ended up getting an after-market swap that worked out.. mostly, it still needs a lil hand holding to pass smog, but what ya gonna do, If you have a honda with 490k miles on it.

Looking forward to finding out what ya find inside that battery.

 

[vintagegarage]

Please do a search on YouTube for Motocompacto, and you will quickly get up to speed. It will surprise me if there isn't more than 100 Motocompacto videos there by dozens of content providers. Honda announced them in September, and began shipping them in November.
What I found inside the battery is back a few posts in this forum, and the first post in this thread by 100percentjake is the best to read to see what is inside. I've already put the battery back together so I can send it back to Honda when my new battery arrives. There is a one year warranty on the Motocompacto, so the chances are very good that the cost of the new battery will be covered by Honda. Honda is supporting the product. The only problem is that the Motocompacto is so new that you can't expect any Honda tech to know much about it. I also think that repairing the battery would take more labor than the cost of a new one. As far as I know, there is no aftermarket battery yet.

 

[100percentjake]

I've already put the battery back together so I can send it back to Honda when my new battery arrives. There is a one year warrantee on the Motocompacto, so the chances are very good that the cost of the new battery will be covered by Honda.

I'll be mildly surprised if Honda accepts a battery that has been disassembled for a warranty replacement.

 

[DaLanMan]

I know the feeling. I have a BMW hybrid, and no, it is not economical, it is a twin turbo that has a 60hp booster electric motor to assist getting over the turbo hump and make your low end launch better... :: it is way too much fun for being what it is...

But every time it goes in for service it is all nervous shifty eyes in the maintenance bay, the only guy "local" to me is like 130 miles out... So I end up with a loaner 2x/year when I bring it in for it's health check...

THey have replaced.. stuff. I have never even opened the hatch where the battery lives. Don't wanna know.. I will pretend it is just a much cheaper slightly crusty M series something.

 

[vintagegarage]

I'll be mildly surprised if Honda accepts a battery that has been disassembled for a warranty replacement.

I hear you and wondered the same thing when I asked the dealer if it was ok if I took it apart to see what was going on in there. I think it is a better than 50% chance that they will. I am pretty sure the dealer will try to honor the warranty, but I guess the request might bounce back when it goes up the chain of command. I am thinking it might be months before the new battery comes in, and then we'll see what happens. It is worrisome that the battery simply blew up on a long Mode 2 ride. If that is a common problem, I think we would have heard about it by now. I guess if they don't honor the warranty, the education of how the battery works is probably worth about $350 to me, so there won't be any tears... LOL

 

[amberwolf]

My guess is the reason for the backorder / delay is that they have had problems with the batteries (perhaps in internal testing or something else they can keep quiet vs end-users that they can't really), so a redesign and testing could be delaying replacements as they build up a stock for a recall, etc.

 

[vintagegarage]

I was going to give up as I am so old, I didn't understand what surface mount meant, as my knowledge is also old. Now that I understand it better, I think I will take the battery apart again and test the fuse. I thought to test it, I would have to test it from below. Now I see that I don't. I ordered a 10 pack of the fuses from AliExpress for $10 including shipping, and they should arrive in 10 days. Later this week, I'll take the battery apart and test the fuse. If the fuse is bad, then I need to learn how to swap a surface mount part.

 

[vintagegarage]

I took the battery back apart and tested the 30 Amperes SFK Series Self Control Protector(SCP). It was indeed open.. 33.1 volts on the right side when looking at my previous photos, and zero volts on the left side, using the corner ground post as ground. The battery has dropped from 33.2 to 33.1 volts in the course of two weeks sitting on the shelf. I remeasured the voltage at V10, and it is also 33.1 volts, so I don't think there is voltage difference between V10 and the right side of the SCP. Now I guess if new batteries are impossible to get, my backup plan is to learn how to change a surface mount SCP. I also did decide to make a video of the Mode 2 range test and what we found here. I spent the whole day today doing the Thai and Japanese translations for the video. In the video I mention endless-sphere.com and 100percentjake and refer the viewers to this thread. I do not know how many viewers might be interested, but I don't have a lot of viewers on my channel. Once I post the video, I'll put the link here.

 

[DaLanMan]

I am gonna assume this scp is fairly sizeable.. if it is bigger than your pinky nail you are gonna want a reflow system. I have one on a soldering station I paid like 60 bucks for, it is not high end and I would not want to dish about with Delicates with it. But I am gonna assume anything that goes on an ebike should not be labeled delicate..
I just peeked at Amazon and yup, it ain't even painful Looky here: you use that to bring the whole board up to closer to soldering temps, reduces the curve for getting solder to the melting point, release the unit, lil cleanup by gooing flux on and using the soldering iron and your preferred method of solder removal (I am old, I use solder wick) little IPA for washup afterwords and bobs yer uncle, you have the chip off. Putting it back on works pretty much the same.. but backwards...

 

[amberwolf]

30 Amperes SFK Series Self Control Protector(SCP)

The good news is that phrase makes it easy to find out about them:

https://www.dexerials.jp/en/products/surface-mounted-type-fuse/sfk0630.html

I may have missed the exact configuration but based on the voltages, presumably it's a 10s battery, with about 42v full voltage? If so, then for this manufacturer's version, you need p/n SFK-4030 (3030 for 9s or lower).
I don't trust ali* or other similar sites for parts, but if you do then here's a source

https://www.aliexpress.com/i/3256801854706549.html

I was going to link to the Mouser specific page for them but for some reason it won't open right now.



others:

30 Amperes SFK Series Self Control Protector(SCP) - Google Search

 

[100percentjake]

I do not endorse doing this in any way because it defeats safety features of your e-bike's battery, but I'll be (ok, my friend who has a hot air station will be) desoldering and jumpering T1 to T3 on mine, taking the T2/heater section out of play entirely. That way I can then probe T2 on my own time and figure out if the BMS is still upset and trying to trigger the fuse. I feel like, to avoid the battery becoming e-waste, I may end up jumpering the pack positive directly over to the positive lead, bypassing the discharge FETs and fuse entirely (these are the only two things in that path to begin with). I doubt I'll be able to retain communication with the motor controller/dashboard that way, though.

My pessimistic side says that some sort of programmed-in limit has been hit and not only has it lit off a hardware failsafe, but there is likely a software failsafe that has bricked the immutable spaghetti in the BMS itself. $300 for a new battery isn't a huge deal for me so I'm fine making mine irrepairable in the pursuit of figuring out what's going on here, but if I can't get a new battery period that's super annoying because I'd like to ride my Motocompacto around at Cars & Coffee this year.

 

[100percentjake]

The battery has dropped from 33.2 to 33.1 volts in the course of two weeks sitting on the shelf.

I wonder if this is because there is still a constant flow of current through the "heater" portion of the fuse at a fraction of an amp?

 

[vintagegarage]

I just put up the video on YouTube. It is currently "Unlisted" so the only way to find it is to click on it here in this forum topic. All of my videos are "Old and Slow" and this one is no different... sorry about that. I'd prefer not to make it public until 100percentjake and others in this thread have had a chance to review the ending of it to let me know if the ending makes sense. The video has chapters so you can skip around in it to see any or all parts of it. If you skip to around 42:25 and then watch it to the end, it will take about 12 minutes and that is the important part. If you find errors, I'd like to fix them before making the video public.

 

[vintagegarage]

I also wonder why a blown SCP prevents the charger from charging the battery.

 

[amberwolf]

Where in the circuit is the SCP? If it's not between the charge input and the cells, then it can't directly stop a charge. But if the system uses the discharge output (that the SCP cuts off) as a reference to know if it's ok to still charge (vs measuring at the cells), *or* it sets (or leaves) the state of the BMS MCU/etc in the "hey, something went wrong" mode where it blew the SCP, and knows also to disallow charge.

(because if something is so wrong with the pack that it would have to blow the SCP *on purpose*, it would almost certainly be so bad that it would not want to allow it to charge)

Also...just to be sure, are the control FETs in the *negative* wire to the batteries, or in the *positive*? It's usually more complex and/or requires different, usually more expensive, FETs for the positive switching, than for the negative, which is why almost all these systems switch just the negative main cell cable.

 

[vintagegarage]

way beyond my knowledge, but it sounds like replacing the SCP may not fix anything. How does the Motocompacto know when a new good battery is installed?