JAG35 40 cell LG MH1 Battery BMS 3rd Pin Hack
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- เผยแพร่เมื่อ 16 ก.ย. 2024
- Many people were having issues with getting the BMS on the 40 cell LGMH1 packs from jag35.com to work, so here is a fix which makes the built-in BMS usable by connecting a wire to the 3rd pin.
The batteries can be purchased here: jag35.com/prod...
Erik, Thanks! I ordered 4 more. after doing the BMS replacement on one, this looks MUCH simpler (less work).
I appreciate your hack!
Guys I did the 3rd pin hack to TP6 and it works, here 3 quick short video that show (not as cool of Erik's video but hopefully useful)
The 3rd pin hack to TP6
Search for: "Scooter Battery 3rd pin hack - 40 LGMH1 18650 - Simple Hack to activate the BMS (ep 01)"
The BMS max discharge amps is 30:
Search for: "Scooter Battery 3rd pin hack - 40 LGMH1 18650 - Max Amp test (ep 02)"
The BMS does have low voltage disconnect at 29.5v:
Search for: "Scooter Battery 3rd pin hack - 40 LGMH1 18650 - BMS Low voltage disconnect test (ep 03)"
Thanks Erik and @jehugarcia
I received a different version of scooter batteries, you wanna try and hack one? I’ll send you a few to play with
Ooh! Yes I would be happy to try to hack one. I will DM you.
thx 4 this content!
Hi Hello Eric
I did the hack and i worked the battery charges now and discharges. But the resistor and wire get extremely hot so i
Put a Small swiTch to
Turn it off and on. Is this
Normal for the wire and resistor to get sooooo extremely hot ? Thanks in advance for the reply. Ed
Just got my battery. When testing for voltage, I get 17.5 volts without any modifications. Should I sit proceed the same way? Also, can I use any resistor that I have laying around?
Edit: I did exactly what you described and it appears to be working perfectly. Got the voltage to show the same at both locations. Charging now. Will report back after I test it out. Thanks.
Is there another ground I can use? That pad is underneath wires that I'm going to keep as is. Are the screws grounded?
I used the ground pad labeled TP7 which is much closer to the chip needed without the need of a jumper wire. Just the resistor directly.
Any updates? Hoping to learn more about these packs before I start modifying them. Thanks for your video.
I have been cycling my packs with this modification daily since before making the video to make sure that everything is ok. So far the cells still seem balanced etc and I haven't run into any issues.
Erik Meike thank you so much. I have 8 of those battery packs. I will be using them for my DIY RV Build. I figure 8 is enough to start my build with. I will start using your hack and charging them soon. Thanks again for your efforts.
will the bms charge the pack without doing this hack?
Erik, is there any specific wattage you'd recommend for the 1K resistor?
Thanks
Quick question - what wattage would you recommend for the 1k resistor?
But the 3 PIN Is a positive PIN if connect to ground Is Dangerous ?
Do you mod the packs for a price.
Thanks for the info!
With this bypass, would the bms always be on? (if yes, would that be good for the battery/bms health?)
Awesome! What gauge of wire did you use for the charging wires?
So the ground pad you have is where they scraped off the word "JUMP" and below that mine says REV:10 E-BIKE BMS. A little research looks like they were from Ubers JUMP E-bikes. scootertalk.org/forum/viewtopic.php?t=6208
Hi Eric, my battery pack doesn't come with a ground pad like yours does. Mine is Revision 10. Where are the other ground pads I could use?
its the same. they just rubbed off the jump logo
does this have over charge protection when charging ?
Erik, thanks for this post!
I have a few of the JAG35 40 cell LGMH1 batteries and plan to attempt the 'hack' on at least one of them. I will disassemble the others for other uses. One appears to have relatively accessible motor and battery wires and measures 34.5v. I want to test it (add motor wires) before doing the hack but I have a couple questions.
1) Do I need to leave the wire 'hack' on the BMS after the 'hack' and the BMS wakes up?
2) What happens if I attempt to charge the battery before 'waking up' the bms? Bad things....?
1. Yes you need to leave the extra wire in place for it to work.
2. It should be fine to charge it before you do this hack. It would be the same as if someone plugged in the ebike this pack was installed in without turning on the ebike.
I plugged in an ebike charger to this battery before doing this ‘hack’ and i heard a LOUD BANG from my ebike charger, and then the charger stopped working immediately after that
What gauge wire should you use for the hack
Is there a connector on the BMS board for the scooter controls that has the pins that need to be jumpered together?
Unfortunately no. There theoretically probably is a way to do everything from that connector, but I have not been able to figure that out yet.
Wouldn't this eliminate the BMS's ability to shut down the output when the voltage goes below a certain threshhold?
It turns out that it does not affect the low voltage cutoff on the cells. There are several other locations where the BMS can disconnect power, and it appears to use those instead. I did some overdischarge, overcharge, and cell balance testing to make sure that this does not affect that functionality, and it appears that those still work correctly.
Hey Erik, not sure if you have seen Jehu Garcia's videos with regards this packs. He mentioned he could not make the onboard BMS to work (not sure how much electronics knowledge needed) but that becomes an interesting point since you mentioned on one of the first comments on this video that the high-low voltage cut off as well as the balancing seems to properly be working. (Colin's comment 2 wks ago).
My question is; how were you able to confirm the BMS is properly functioning? BMS typically only shunt few tenths of mA's and while connected to the the cells is very difficult to measure which cell is under balancing and which one is not.
I found one of those packs on the sidewalk when walking on the streets here in San Francisco, and those packs where originally manufactured for that Uber JUMP e-bike ride-sharing company, which where scrapped a few months ago. Wonder why so many of those packs around now.
I can't answer for him but any BMS will stop drawing current once the battery is charged. That's a pretty easy way to tell.
Yes, I saw that, and that was part of what made me make this video since I figured it would be helpful. I was able to confirm that it performs some BMS functions by that it has overvoltage and undervoltage cutoff. It also appears to do most of the balancing when charging. If I charge a pack, the cells go from slightly different to exactly the same according to my multimeter as it fills, and I repeated this test after a couple more weeks of daily cycling. I think all of these are signs of it balancing properly.
My guess is that the bikes were all scrapped and some company finished tearing them all down, and thus they are quite available now. It may be that some quantity of them don't work since they are not sold for the BMS, so I guess that part is luck of the draw.
I also have not been able to find the original manufacturer of the packs. If someone can find the manufacturer, someone there may be able to help with getting actual data out of the BMS which could include more interesting data since they do look nice.
Any luck on the can bus data?
@@ErikMeike So I grounded pin three as indicated and the motor port is enabled. I noticed it charges to around 41.5 then levels off at 40.5 after a while. My question is: This is overvoltage protection? So if we use the motor port does it have undervoltage protection? if it is balancing do we still need an additional BMS?
@@ErikMeike On one of the packs I found, it states "BYD Company Limited". I suppose BYD stands for "Build Your Dreams" pointing to the big chinese battery manufacturer. I don't know whether they produced the BMS too, but maybe it's a hint...
it worked for a couple of mins then, motor out shut off. cant get it to output again. Ive tried linking link_a and link_b for a few sec to wake up bms. nothing. The battery is fully charged around 41v. i can read 41v on the mod pin 3 and ground, but it will not output power thru MOTOR + -
suggestions?
Any luck?
Hello!
Is there a specific direction to solder the resistor?
No, it´s bipolar.
I don't have that big ground pad, instead, I have the words JUMP in that area. Was it just scraped away? Do I have to go that far? I see a pad labeled TP7 just above the chip with continuity to the area you originally used. Looks close enough to solder the 1K resistor directly without any wires needed.
Is that going to work? I don't have that much experience with these, just enough to get me in trouble.
Did you end up using tp7?
@@jphein yes I did, but I only got voltage from MOTOR +/-, and I don't get anything from BATT+/-
@@rlsoriano There is an ideal diode on the BATT+/-. By design it only allows you to charge through it. Use the MOTOR+/- for your load. =] I ended up using one of the TP pads too. It works well! =]
@@jphein are you charging and discharging from the same pads or did you separate them out?
@@rlsoriano I did what you suggested, and soldered the resister straight from pin3 to the TP7 pad. Then I charge through BATT+/-, and discharge through MOTOR+/-. although I think you can charge AND discharge through MOTOR+/-if you want.
I only got voltage from MOTOR +/-, and I don't get anything from BATT+/- is this correct?
The same, I have the voltage only MOTRO+/-
Do you have description of that , I can't see clearly
Here is a closer-up picture of the pin on the IC: photos.app.goo.gl/9SJSyfEGRS1nfBSm9
Two questions. I shorted pin 4 on the IC of one of mine and I'm wondering if you know the name of the IC so I can replace?
Also the Bat +/- terminals don't show any voltage and don't accept charge. What's that about?
Thanks.
If the batt terminals don't take power or give power, that means the battery is probably full.
For your second worry, I would still complete the hack to see if it survived since I think it would be a fair bit more work to replace the IC, and if you were quick enough it probably didn't damage it too much. I believe this is it on Digikey if you do need a new one: www.digikey.com/product-detail/en/infineon-technologies/BTS500851TMAATMA1/BTS500851TMAATMA1CT-ND/2231100
@@ErikMeike The IC partially exploded haha. I have the equipment to quickly replace it so I should be good. The battery terminals show no voltage on any of the packs I have hacked thus far. The batteries are not full either. The battery terminals take current if force charged via a variable power supply but the lithium ion specific chargers don't recognize it.
@@ErikMeike Are the Batt +/- terminals supposed to show voltage? There is no voltage showing on any of the 6 battery packs I received. Thus my charger does not recognize it.
@@colinleamy6199 It has an ideal diode IC, so it will only accept power input on the battery terminals and not output any to the charger sense circuit. You can probably trick your charger into thinking it is a direct connection to the battery by adding a resistor between Batt+ and Motor+ after you perform the hack. A maybe 10Ω-1kΩ resistor probably would work fine as long as the wattage is high enough.
@@ErikMeike Yeah I found a way to force charge on the charger. Thanks :)
I tried to take out the IC on the one that I broke and holy crap this thing is a serious heat sink. I dumped 480 Celsius full blast for 10 minutes with my heat gun and it did nothing and cooled down very quickly after letting off the heat. I think it's safe to say that I cannot use the BMS on this one without getting hold of a beast of a heat gun.
What voltage 1k resisor
I have two LEMH1 batteries. Both have the pin3 hack in place. One is working even remove the charging input from BATT(+/-). The other one's BMS shutdown immediately if I remove the charging input. May be I need to do something on SP2(WKUP) or SP1(1-WIRE)?
What voltage are the cells at/how much did you charge the pack to?
@@ErikMeike the pack is at 40.4v now. try to charge it to 42v. it seems that output BMS is enabled but not charging (no charging current). If I put load on BATT(+/-), I see charging current-maybe the charging current drive the load, not the battery.
@@yanmingpeng645 Does it charge if you discharge the battery a little? It seems like the BMS may cut off at close to 4.15v per cell and then they drop down to about 40.5v after they sit for a while while the BMS still doesn't allow charging.
@@ErikMeike I discharged it to 37.8v. still not able to charge it via BATT+/- (no charging current), however, the MOTOR+/- will be activated as long as charge is connected..
@@yanmingpeng645 I have the same problem, received my battery pack yesterday. I charged my pack to 40.9v via the CELL+/-. With the resistor installed charger connected to the BATT+/- pack does not seem to charge but the MOTOR+/- passes through the charger voltage, battery pack voltage does not change or charge.
Great thanks! 👍😁
Any updates on your testing?
Well I tried it today... but it did not work on my pack... unless I did it wrong. I did have to use a 1.5K resistor (all I had). I just ordered an aftermarket 36v BMS. Thanks anyways.
@@cocojones3479 I am currently waiting on shipping for getting some CAN breakout boards to try with the reverse engineered CAN code. I had some at home but moved and they got lost in the reorganizing stuff.
@@ErikMeike that's great Erik. Thanks 😁👍
@@ErikMeike Any pointers to that CAN code ? Couldn't find it on the Jehu video even though it was mentioned.
@jonansan github.com/alex3dbros/LGH1ScooterPackPower
Is there any documentation I can see ? Can NOT understand what your on about. Where does the jumper go ?
Look further down in the comments. Someone else has the same question and he posted a link to a picture.
_edit_ Built a shunt and measure ~25 to 28amps on a fully charged battery before BMS shuts down.
-Anyone able to use a single pack and pull more than 10-15amps?-
-With Erik's modification (thanks Erik!) the pack works great as long as I don't pull much more than 10amps-
Too late. I already ripped the BMS off of the two I own... :(
@ZEN ONE I'll give it a try...
From top to bottom I read: LNK_A , LNK_B , GND , CAN_L , CAN_H , VSYS , WKUP , 1-WIRE
@@StarFyter1 what colors correspond to these labels? Could we possibly short WKUP and GND together and get the same outcome?
Damn, I can't hear the narration over the noise .