EGO 56V Battery - What is the D-Terminal?

[@groeszs]

Thanks for sharing this. I'm currently working on reverse engineering and mapping out the electronics of the EGO batteries. Your videos and the community response to my idea has inspired me to look into what it will take to keep these batteries operating.

[@ThriftyToolShed]

That is awesome sir. I have give it just about all I have, not sure without trying to pull the program out of the microcontroller(s) if I could go any further on this D terminal. I also desire to keep these tools and batteries going, I do love the power of all my EGO tools. Thanks for your comment and Best of luck to you!

[@groeszs]

​@@ThriftyToolShed It would be impressive if the code could be recovered from the micros, but I very much doubt it. I contacted EGO briefly, but of course they have nothing set up to provide replacement parts to repair their products. The next thing to do would be to reverse engineer the OEM parts and make compatible parts. It all requires time, of which I wish I had more of. I would bet the D terminal is using a One-Wire or i2c communications bus. Using a logic analyzer, you should be able to record the communications between the the battery and the tool, and the battery and the charger. At best, the waveforms could be analyzed and a coherent protocol can be discovered. At worst, hopefully the waveforms can be recorded and then played back to simulate communication. No matter what, I don't think we'll be able to copy the firmware, so the communications protocol will need to be analyzed and replacement firmware written. Of course, if Ego suddenly decides to start providing parts, I would probably be less inclined to hack their stuff... Feel free to IM or e-mail me or contact me in the forums if you have questions or ideas. If you figure anything out I'm sure you'll share with us. If I create something, I'll share with you :) There are a few things I will not be able to repair or replace. First is the phase change material. As far as I can tell, it seems to be closely related to WAX, similar to used in candles. For now, that stuff is irreplaceable, so recover the wax sleeves from any battery cells that can not be recovered. The sleeves can be placed around new cells and new sleeves shrink wrapped around the cells. Also cannot replace the housings, I haven't found a source for the high power terminals, and of course the PCB and other miscellaneous hardware. though the PCB is just a matter of time before I will have a replacement available. Hopefully more reliable than the OEM BMS. Also need to figure out how different the new BMS is, maybe they made the new BMS more reliable, in which case I don't want to waste my time on the old model. Unfortunately, I don't have a new BMS on hand.

[@ThriftyToolShed]

@@groeszs I don't have a newer BMS either. I have been fortunate enough to get ahold of a dozen or so of older packs and repair so I do not need any for now. So it's hard to justify buying a newer pack although that Nexus power station with 7.5ah would be awesome! I feel as you do about the one wire protocol on the pack to tool, I assume they use it for several things. Obviously for tool shutdown when pack is depleted, overtemp and also I noticed they claim that the chainsaw can change performance depending on which pack is connected! I have a good many tools over the years and really enjoy learning, one thing I don't have is a logic analyzer! BTW one veiwer mentioned the phase change sleeves are paraffin wax and carbon graphite which seems correct after I examined some of mine. Thanks for the information and Best wishes!

[@maddmikemu]

@@groeszs I have been thinking about the D terminal also, in terms of cell balancing. The BMS has to communicate with the charger to switch off so that it can drain and balance the cells (assuming a typical passive BMS that balances that way). Have you gotten any further in your reverse engineering of the protocol? I'm wondering if there is a way for us to know when the pack cells are out of balance and how the balancing happens, how long it takes, and whether the BMS/charger indicates the pack is fully charged even if cell balancing is ongoing. I don't know if the cells on my 2 packs have never needed balancing or if they have but there is no way to know by looking at the charger or pack indictors. Many people use EGO batteries for ebikes and other PEV, sometimes using a non EGO charger so no D connection. I wonder if the EGO will still balance if charged without the D connection. Thanks!

[@groeszs]

@@maddmikemu I haven't had much time to pursue this. I am glad there is still interest. Currently, I am in the process of building adapters so I can listen in to the communications, so, soon (?) hopefully.

[@johnbriggs7514]

This is clearly still an ongoing challenge. I wanted to drop a link here, but I don't know if KZbin allows that. Suggest searching "I have reverse engineered some messages between my quick charger and 7.5 Ah battery." With the quotes to find more detail on Endless Sphere.

[@ThriftyToolShed]

Awesome, I will have to check it out! Thanks for sharing!

[@RogerLacasse]

I'd be interested to see a Nexus Escape teardown. I'm wondering if scavenging the Escape controller and using it to power projects could provide a way to get around the D terminal problem while preserving battery protection.

[@bkj242]

Great work indeed. This is most helpful as was your T terminal video. I’m working on a 2.5 Amp hr now with a very odd DTC resistance reading on the lower pack which I believe is causing a charging issue. Status monitor shows green but charging will stop after the first “blink cycle” (red-yellow-green), more later after one additional troubleshooting step. Thanks

[@bkj242]

I meant to say the NTC thermistor. The pack T terminal measures normal ~11K to the negative terminal but the thermistor of the low cells measures ~ 4 ohms when measured on the BMS. Pack will not charge with all cells balanced. Using another BMS where thermistor of low pack measures ~ 10K at BMS, pack charges normally. Ever encountered this with any of your packsaddles?

[@ThriftyToolShed]

Yeah, I figured you meant NTC. I have not experienced that exact issue. The T-terminal sounds good. You are saying the NTC on the cells with the small black leads are reading fine (around 10K or so) Then you plug it in the BMS and then it shows low ohms reading, like it's on the board that low ohms? I have seen the NTCs themselves give issues, but not the board on the Thermistor input other than corrosion / bad connection. I haven't seen it have a low ohms reading like that on the NTC terminals!

[@bkj242]

@@ThriftyToolShed yes on the BMS with the harness connected to the BMS the resistance across the thermistor at the L pack terminals reads under 10 ohms. Have not the thermistor leads on the connector when it isn’t connected to the BMS. Swapping another BMS, charging is normal. Something on the one BMS is pulling the L pack thermistor low. Thanks

[@OhioWhitewater]

JS, did you figure out your problem with the ohm reading between ground and T dropping when the BMS is connected? I have a water damaged battery which was working until I tried to charge it before it was completely dried out and after charging for maybe 10 minutes something fried both on the battery and on the charger. Now there appears to be no continuity at all when I measure between ground and T. The battery still has almost 56 volts and still runs the tool so the D terminal seems to be working. It will not charge on another good charger I have so something is clearly wrong with the T circuit. I'm running a 18-in chainsaw with it which uses both D&T so I'm not sure how the saw is working without T functional.

[@toolscientist]

Looks like maybe a bidirectional UART. The presence of R19 (the 200ohm between D-pin and Q13 collector) means that when the micro opens Q13, the tool won't see ground, just a lower resistance. I guess if the tool/charger also has 10k on that line, it'll be close to zero. I'm guessing it's a similar dual purpose pin like M18. Maybe serial data in charging and an enable/disable pin for the tool. Those pulses look more like motor noise than serial data. I'm fairly sure XGT has a separate isolated ground for communication so that it can communicate whilst the tool is running - otherwise there's just too much noise when data shares a ground with the main power path. It could still have serial data during charging as the charger can keep the power input fairly clean.

[@ThriftyToolShed]

All good points. I also feel the same way about the noise on the oscilloscope. Especially since it would only show up once the tool started and I feel like the communication starts when inserted in the tool. Most tools blink the packs fuel gauge when inserted so surely at least a small amount of data is tx/rx. I should have mentioned on video that the 15Khz was most likely a carrier frequency of the motor output. I am used to seeing that in industrial drives to a degree.

[@toolscientist]

@@ThriftyToolShed good point, there could definitely be some data transfer before the trigger is pulled. That would be enough for the battery to give some parameters to the tool. I looked for that specifically on M18, but pretty sure there's nothing. Could be something on One-Key or newer tools.

[@fishinman69]

Thanks. I was wondering if you would make a video of that d terminal I asked on your other video

[@youtubular007]

Thrifty - what would be your advice on how to set up a protection to 4 EGO batteries wired in parallel to run a non EGO motor so that the batteries do not damage each other if the bank becomes unbalanced and also that any battery would shut off or cut off if the SOC or remaining capacity drops too low? Since it seems the D terminal would normally handle the low voltage or capacity shut down via a conversation between the BMS and the tool I don't know how we can leverage the BMS's at all to help with this. EGO must have some way they are addressing the multiple battery safety since they have several tools that use multiple batteries like the Zero turn, the backpack blower, and the snow blower and maybe others but perhaps that relies on the D-terminal as well.

[@ThriftyToolShed]

Yeah, the D-terminal is a strange one, and it is going to be hard to get to working in our favor for sure. I can not speak from experience at all on these packs with 4 in parallel to be clear. I have not had to do that myself, but schottky diodes are most likely needed to keep from back feeding and then maybe the individual packs can be monitored individually with either a low voltage cut out board as I have discussed and shown before or a simple trick is the cheap battery voltage indicators that have an alarm feature. I would imagine you could even remove the buzzer and make the output trigger a mosfet or optocoupler, etc. and then, hopefully, all will be monitored individually with 4 of those circuits. It's always a risk with any design, and that is 4 packs, so be careful as with any modification. Be safe and have fun. Wish I could help more, and best of luck to ya!

[@martinair329]

Thanks for the videos. Interested in how the battery shuts down if Volts get too low. Repurposing batteries for e-bike project and from what I gather, the shutdown sequence on low volts is partially on the Battery BMS and partially in the tool. As I will not be using the tool, I'm curious as to how I can gather the parts from a tool (if required) to have the EGO low voltage shutdown function operational on the e bike. Any suggestions or other videos you can suggest?

[@ThriftyToolShed]

I still have not figured out the communication between the D-terminal so the tool controller has to communicate with the pack so when BMS senses low voltage it tells the tool to shut down. The only progress I know of is slow. I did a video on the Ruzuit 56V battery for the EGO equipment. It is aftermarket, so good news is someone has reverse engineered the pack and figured it out. Not so good news... I have contacted company about BMS parts etc. But as I suspected, no response back. As mentioned in that video the price is not that great of savings, I bought one simply out of excitement to see how close the BMS is and if it communicates and it does. The only other work around for yours that comes to mind is wiring in a separate BMS of your own off of the + and - of the EGO pack and not even bothering with the EGO feedback. If you really wanted to, you could build your own low voltage detection but may cost in components the same or more than a BMS on the market. Best of luck to ya!

[@martinair329]

@@ThriftyToolShed Yes, just seems like a shame to not use what is already there. This e-bike forum has an EGO following and on page 4 of this thread a guy seems to have made some progress...endless-sphere.com/forums/viewtopic.php?f=14&t=93563&p=1557318#p1557318

[@jaydavis852]

For anyone having similar issues, I had an issue where my mower, wipper snipper and leaf blower would run for ~5 seconds before they shut down, the fuel gauge on the battery also didn't light up when the tools were turned on (although the fuel gauge worked when you pressed the button on the battery to check the level). I tried powering the tools using my home made ebike battery but had the same result (ran for only ~5 seconds before powering down). I figured that the issue must be with communication over the D terminal. I pulled the board out and checked it under a microscope and found that the 200 ohm resistor (R19) across the data line had blown and had gone high resistance. To test, I removed the blown resistor and temporarily bodged in a 200 ohm through hole resistor and it fixed the battery. I will order an SMD resistor to replace it and all should be good. Hopefully this helps others.

[@ThriftyToolShed]

It will be interesting to see how many viewers have that same issue. I have not seen it. Very unusual to have a blown resistor on a data line. Thanks for sharing!

[@timkostka]

Do you by any chance know the part numbers used for the battery terminals? Both on the battery side and on the tool side. I'm sure I can use a generic spade terminal on the tool side, but it would be nice to know what the genuine part number is. Can't find anything similar to them on Digikey. Thanks!

[@ThriftyToolShed]

I am sure it's a custom item EGO makes for their own manufacturing. You can find some generic battery blade style adapters on Amazon and eBay and may even find some similar to the below example. But basically that or you have to make your own. www.ebay.com/itm/275986283413?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=o5qkd7YgSJW&sssrc=4429486&ssuid=D_qZMHXJQNK&var=&widget_ver=artemis&media=COPY

[@captaincanuck7110]

did you try a serial decoder through your scope on the d (data) terminal?

[@ThriftyToolShed]

I have not. I was hoping to get to that point since all I really seen on the scope is likely a carrier frequency from the controller output. It has been several viewers that have taken it that far and were much closer to decoding it, but I have not heard back from them since. Once I seen aftermarket clones of the board (in aftermarket packs) I backed off spending anymore time on it since I know it has been done to a degree and we have a possibility of getting spare boards. I hope to eventually see these BMS boards for sale. I have asked a couple manufacturers about buying a bulk quantity, but no success yet.

[@mikecastillo3809]

Thanks for all your research into the d terminal. I have looked all over and it does not appear that anyone has totally figured out the 'protocol'. My use case might be a simpler problem that you might have some ideas about how to solve. So much of the information I have found on the d terminal is about it's communication with the charger. My interest is on the 'tool' side. So what I want to be able to do is power my EGO lawnmower with a non-ego source of power. It sounds like if I put the right voltage and current to the lawnmower that it will likely run for 10 seconds and then stop since it can't communicate and get the proper information it needs from the d terminal. At least that is what it sounds like happens on then leaf blower. Can you think of a way to 'fool' the lawnmower into not stopping after 10 seconds? Maybe just put a high voltage value on the d terminal line, or maybe connect to ground (negative)? Probably not, but maybe there is something simple that just tells the lawnmower it's OK to run. Any ideas would be appreciated. It would be interesting to know what the tool's controller and the battery's BMS are discussing over that channel, but as you, and others, have found, this is not an easy thing to do. If knew the protocol, I could do program a microcontroller to make the tool happy, but without the protocol, no way what I need to tell it. Thanks again for all your great information on EGO batteries. Peace, Mike

[@ThriftyToolShed]

Hi Mike, Yes,I am at that exact spot for sure. I have not gotten any further with the D-terminal communication. I have had a guy contact me and he mentioned he had some better equipment for testing and was working on the serial data bits etc. Unfortunately he has not contacted me with any further updates. I also shared a few aftermarket packs in videos that are 56V replacements and I was impressed with the fact that they did clone the BMS board and it works well with the EGO equipment. Some people are not thrilled about those packs nor did they like the idea of purchasing these Chinese packs. My Main point was simply wow, they figured out that pretty quick. I am atleast impressed with that part. I have tried my best working with the manufacturer and they still will not sell the BMS board separately. I tried. The only way I know of at this point to run the mower with other than EGO or the knock off EGO pack is replacing the mower controller which is not what anyone wants to do really. I have a video replacing the mower controller and I can run it from 40V - 60V source. The only reason I done that of course is I bought a mower non-working and saved money by doing it that way. Thanks for your comment! Best of luck to you!

[@dustinsutton4282]

Dude your so advanced I want so badly to learn this stuff

[@dustinsutton4282]

Quick question I have several ego batteries that I've charged to the voltage by an unorthodox means however once inserted into a tool I only get until motor startup then red flashing I went through all temp transistors to no success. Could I possibly run a 10k resistor from neg to D terminal and confuse the motor controller.

[@ThriftyToolShed]

The D-terminal seems to communicate so there is no easy bypass that I have seen. Thanks for your kind comment!

[@dustinsutton4282]

Yes, think I'm going to have raise the white flag on this one. Geez, I don't get my ass kicked often

[@DIYGuy85]

Do you think you would be able to charge a DIY 14S battery with the charger without the D-terminal of charger connected to anything? T is easier to jerry-rig as I just have to get a NTC termister as you mention in the video. Not sure if the charging will work without the D.

[@ThriftyToolShed]

In my experience with the chargers, you will need the D-terminal communication between the pack and charger to charge. Some maybe different, but all I have seen have to be connected to D-terminal. A 60VDC supply or so and a Drok DC-DC converter is one easy way to charge 56V packs. I have a similar video showing the Drok in action, but similar converter should work as well. I have not tried to charge without the D-terminal enough to know much about it honestly, just my thoughts... Best of luck with your project!

[@DIYGuy85]

@@ThriftyToolShed Thanks! The only reason I don't want to use a 60VDC power supply is that it will not have the characteristics of a lithum charger. Which may damage the cells in the long run. Generally, proper lithum chargers (like the Ego) would provide constant voltage & constant current until the battery reaches a certain voltage (4.0V/1 cell) then the current will slowly be reduced over time to lower and lower amps until the battery is fully charged (4.2V/cell). This is hard to replicate in DIY setup. Ofcourse I can buy a dedicated charger but it will be extra cost when I have 3 ego chargers laying around.

[@ThriftyToolShed]

@@DIYGuy85 That is the entire point of the DC-DC Converter. In may videos I discuss the CC and CV relationship and the Drok or any CC CV converter makes it very simple and easy.

[@DIYGuy85]

@@ThriftyToolShed oh ok. I will check it out. Thanks

[@tylertakes2241]

I haven't seen go over how the battery powers the BMS board. You reference it a bit in the video where you fix the BMS with the flashing green light. Ive got a pack where all the cells are good and balanced at about 3.6v and im getting 50.4v at the main terminals and 50.4v into plug that powers the BMS board(two small red wires) Yet i cant get the power button to light for anything at all. And it wont charged on a known good charger. Any ideas?

[@ThriftyToolShed]

Well I have not had to troubleshoot that problem specifically, but I do know the test button wakes up the DC-DC Converter on the board. I mention this breifly in this video that is really all I have checked in to that part. Hope it helps a little bit, all I know is to check the bus voltage accross the capacitor when pressing the button and see if the converter is powering on!

[@tylertakes2241]

@@ThriftyToolShed ​ I was taking a closer look at my BMS board and came across something i thought might be helpful and you would probably be able to put it to better use then I'd be able to. I was getting a light on my board and it shined up from the bottom through the board and it revealed all the traces and how they travel from each component through the board like a map. Hopefully that made sense. I could get you a picture of what i mean if you need but it could be useful on other projects as well. Thanks again!

[@ThriftyToolShed]

@@tylertakes2241 Yes, it does help. I do that often with boards for sure. Some boards have so many layers and vias from one layer to another that it can be difficult to see. Yes when I am following a Trace, I always have a flashlight close by it will help some for sure, at least see the direction it is going. Thanks for your comment!

[@robertogodoy4882]

I'm having trouble with one of these batteries, 56v 5ah ego, where the bms button doesn't light up, it doesn't charge, and if I use it on a mower, the mower runs for a few seconds then the mower itself blinks green and orange. I have tried to use your videos to help me troubleshoot it, the battery has a whole 54v left, but I am uncertain how to tell what else could be the problem if its something on the circuit board. Any chance I could get some assistance?

[@ThriftyToolShed]

It's good that the pack has 54V so hopefully the cells are ok. You will have to measure across each cell group to make sure they are truly balanced, but at least that is a good sign to have 54V. The problem is most likely with the BMS board. If the button will not even light up and you have 54V on it then the board is faulty. The mower will only run for a few seconds and shutdown if no communication is established with the pack. I would check the connectors to the board and make sure they are making a good connection with no visible corrosion. The cause many times of this symptom is the DC-DC converter on the board is not working. It can be any components causing this in that part of the circuit. One of the most common is the small silver cube. it has 3 coils and many times one of those coils is open. I have not found a replacement for these. I will sometimes use one from a donor board since I have collected a few over the years of working with these from time to time. Best of luck to ya!

[@robertogodoy4882]

@@ThriftyToolShed I have in fact checked all the cell packs and got 3.91V on each. I’ve also checked the connections on the connectors and there is no corrosion on any of them. I’m sure it’s something on the board, but not sure which component, thanks for the help!

[@maukaman]

Nice videos Thrifty Tool Shed! I recently acquired an Ego nexus inverter that didn’t come with a battery. I have the guts from an Ego battery that I dismantled a while back. I am attempting to re-assemble it with a fresh set of cells, but I want to be sure that I connect the bms leads to the correct cells. Can someone tell me exactly which color wire goes to the correct side of which cell? I’m really hoping I can get this pack operating like it’s supposed to so I can use my new nexus inverter! Thanks!

[@ThriftyToolShed]

Which pack did it come out of a 2.5AH? It is a older style pack correct?

[@maukaman]

Thrifty Tool Shed thanks for the prompt reply! Yes I believe it was a 2.5 AH pack, older one. 14 cells. I assume the colored wires would be the same in all the 2.5 AH packs? I could probably figure out which color wire goes to which cell set by studying screenshots from your videos but I want to make sure I get it right the first time and that is a bit difficult. I’m hoping I can get the pack reassembled and working then hopefully add additional cells later to increase capacity. Hope you had a nice Thanksgiving, Thanks for the help!

[@ThriftyToolShed]

@@maukaman Thanksgiving was in deed great, hope yours was as well. I will try to get a video uploaded showing the pack, most likely the best way to communicate the wiring? Someone else may find it useful as well..

[@ThriftyToolShed]

Eric, I posted a quick video showing a lot of detail about the BMS wiring hope it helps! if so please share.... kzbin.info/www/bejne/iJe3e4J6pM1rh5Y

[@hjc0706]

is it possible to keep the mower at full torque by adding a switch? I'd like to keep it at full torque to pick up leaves better. As it's not adding enough resistance for the sensor to demand it.

[@ThriftyToolShed]

I am not aware of a way to do so with a switch. It seems to be monitoring motor load within the controller which is hard potted as shown in my LM2100 mower troubleshooting and controller replacement videos. Of course I can cut my repaired mower up full output from the replacement controller with a potentiometer. The original controller has no way to adjust this available to us. The only possible way might be installing 2 high lift blades 90 degrees apart similar to the select cut style and it's possible to keep it loaded at all times that way. Just a thought, I have not actually tried it myself. On some models the high lift blade alone may keep the rpm up more?

[@hjc0706]

@@ThriftyToolShed I also have the older self propelled model and it's always been my complaint that none of the ego mowers have a "turbo" button to keep the RPM high. I used the high lift blade and since switched over to the cross blade, but on both blades the RPMs drop when its not actively cutting tall grass. Hence making it really useless for mulching or bagging leaves, since it just idles.

[@ThriftyToolShed]

Man, if it even idles with 2 high lift blades offset 90⁰ it will be hard to keep it loaded with small debris for sure. If you ever do have a controller go bad you can just install the cheaper one like I did and run it whatever speed you like.

[@matgyver2360]

D terminal = Digital terminal? Communication terminal between processors for battery protection. If battery overheats or depletes, it tells tool to stop in order to protect battery? Do you suppose two batteries could share this D terminal to tool? I haven't checked the system on a dedicated dual battery tool. I suppose a dual/multi battery tool has two or more processors (one for each battery). I'm looking to add more batteries to my mower. I could do it without D terminals, but the protection wouldn't be there anymore. Any Idea? Thanks, Mat

[@ThriftyToolShed]

I mentioned alot of this in the video. The tool will only run for about 10 secs if no communication between the tool and pack on the D-term. At this point the only way really is putting another pack in parallel, the + and - . It would have to be done properly or at the very least care must be taken to make sure the charge level of the packs are the same and the capacity of the packs must be extremely similar. The pack added will not have the protection of the low voltage cut off or temp monitoring of course. That is the only way that I would know still. I did check out the Ruzuit battery pack made for EGO equipment and I only done so for one reason, to check out how well they done the BMS board. They copied it well, so that means they figured it out. Unfortunately I have not had success getting up with them to see if they would sale the board as a spare part. That would be very helpful. I did a video on the battery because it is a very close copy of the newest EGO BMS. Not really worth the money, but interesting that they figured out the D-terminal.

[@matgyver2360]

@@ThriftyToolShed Yes, you did mention that the tool would only run for about ten seconds, this is why I asked about parallel connections, not absence of. Sounds like you haven't attempted parallel D terminals. I plan, of course to use similarly charged packs, but I will be installing fusing between packs to avoid an expensive dummy mistake. I may test this out to see what happens as far as parallel D's. You haven't tested with any multi battery systems such as ego snow blowers?

[@ThriftyToolShed]

I don't have snow blowers at all since I live in the south. That is a very good point though. I don't think the D-terminal should be paralleled due to this being a 2 way communication link between the tool and pack. I was simply referring to the one pack using the D-terminal and the other pack + and - being in parallel and of course the protection as you mentioned at least a fuse, at best battery isolation using high current diodes etc. on each pack.

[@matgyver2360]

@@ThriftyToolShed Not to worry, EGO has a rider mower coming to you soon! The rider will have up to six battery compatibility. I may investigate a bit into one of my snow machines to see the communication methods. BTW love your channel. I must say, the first video of yours that I watched opened my eyes to a lot of basic troubleshooting. Thanks!

[@ThriftyToolShed]

The mower looks cool for sure. Thanks so much for your comment!

[@fishinman69]

So how do we mimick term d so I can put non ego batteries on ego products

[@ThriftyToolShed]

I have tried all I can as mentioned in the video. "Sorry" I can only show what I know. I am hoping someone else can take it further. Trying to ignite an Electronics Engineer, designer or microcontroller expert! I have had more than one comment that the viewer has a desire to reverse engineer it, so let's hope!

[@groeszs]

Why would you want to use a non-ego battery? (serious question) The answer to your question is two words - Logic Analyzer.

[@fishinman69]

@@groeszs I have 4 5ah batteries from another blower 60v that I hooked up onto my ego backpack blower. It would only run for 4 to 5 seconds because of the D terminal. I found that out because I hooked the ego battery without connecting the D terminal and it did the same thing. So 2 reasons why I want to use diff batteries (1) I have 4 extra non ego batteries and (2) the extra couple volts was enough to blow leaves so much better without using the boost mode! Oh and the boost mode turned into beast mode lol

[@groeszs]

@@fishinman69 Interesting. Hopefully we'll eventually be able to accomplish what you want. I wonder what would happen if you connected the power terminals from your 60v battery with the D and T terminals from a charged EGO battery - would it be smart enough to know...

[@fishinman69]

@@groeszs didnt work when I tried.

[@WargateXGWU]

I need help! I have an Ego 4AH 56V battery. Testing each cell via the B1-B14 terminals, I have the right voltage on each cell, except that B13-B14 gives me negative 3 volts. What would cause that? How do I fix it?

[@WargateXGWU]

I did find it's definitely on the board. I tested the individual cells.

[@ThriftyToolShed]

I have found the connectors on the BMS where the cell wiring plugs in have bad connection and I cleaned them up really well and it can sometimes solve the issue.

[@superspeeder]

Great video! I was wondering if you had any insight into the boards that cover the ends of each cell stack and have a component contacting the end of each cell with some sort of silicone or thermal transfer medium? If I remember right, each board only has two leads connected to it.

[@ThriftyToolShed]

I think you are referring to the end of the pack halves? The are simply jumpers across the cells and it is wires attached for individual cell monitoring. The only board is the BMS and then the connection board!

[@superspeeder]

I’m looking at a defective 4Ah battery I got on EBay. There’s a board on the end of each cell stack that has 14 “Q” components, one for each cell, touching the top of each cell (or the strap welded to the cell). They are in the middle of the battery pack. These boards appear to be connected in parallel and go back to the large black connector (top right) on the BMS board. Wires are green and red. The connector on one board has four pins, two in and two out to the other board which just has the two pins. This almost looks like part of the temperature circuit, but I’ve never seen an arrangement like this before and I don’t have the experience to trace through the BMS.

[@ThriftyToolShed]

Sorry, I am not familiar with the 4AH at all. I was thinking it be identical to the 5AH just 2000mAH cells instead of 2500mAH cells, guess I was wrong! I haven't seen a EGO pack like you are referring to! BTW, it's not the newer style pack with the charge level indicator by chance is it?

[@superspeeder]

So I looked at both a 2.0 and 2.5 Ego battery and neither had the middle boards I'm describing. I looked at a 5Ah and it has the same boards as the 4Ah. None of these batteries have the new charge level indicator. I'd be interested in your thoughts if you ever get into a 4 or 5Ah battery.

[@ThriftyToolShed]

@@superspeeder Well it is very odd that the 5AH you have is not the latest updated pack. I have repaired one 5AH pack and it is similar to the 2.5AH really as far as the BMS and monitoring goes. I am wondering if EGO may have a intermediate version of the packs that I am unaware of. This link is to the 5AH if you want to see inside of the one I have for comparison. kzbin.info/www/bejne/an-ohH6AZceYd8U

[@nomadchad8243]

I bought a ego+ inverter that i was going to power with my 56volt ebike battery but I think im being stoped by the D terminal. :(

[@ThriftyToolShed]

Yeah, that's a tough one. I have tried to learn more about it. Without schematic and microcontroller program it's really difficult! At least if you have a ego pack you can still use the ebike pack as parallel extra capacity! Good luck to you!

[@jacobecorder]

@@ThriftyToolShed i was under the impression that 2 lithium batteries in parallel without isolation would be dangerous. What do you know about this? I isolate because of this. But I would rather not if I didn't have to because I am currently not able to utilize regen braking on my remote controlled mower because of this barrier. I pasted this before but I'll post it again for reference to what I'm talking about here. kzbin.info/www/bejne/oXfUoKiQq7SEd6c

[@ThriftyToolShed]

Jacob, I have watched your video and subscribed, I think I commented last time that I did really like the mower and I actually have a design drawn out very similar for my own mower to work extremely similar from several years back. I ended up moving to a much smaller yard and unfortunately I really could not justify the money to build it for my yard size now. My dad used to have a small engine shop before he retired and I used to have ideas of building and maintaining remote control and robotic mowers. Over 15 years ago, you really did not see that around. I was playing around with Basic Stamp microcontrollers etc. Way before Arduino became a thing really. I had plans... I was planning on using similar tires to 4 wheeler front tires. Yours seem fine, I really like it. Anyway, as far the batteries, you are very correct, you need isolation. The only time that I would not would be in the example of the Inverter power station in a emergency situation and no power, as long as they are very close in charge (I would absolutely check that first) then I would parallel off the + and - in that situation. Any other common repeating use absolutely should be isolated in my opinion. Did not mean to add confusion to that, really just talking about the D-terminal and the best or really only way around it for the Power Station in a needy situation.

[@walterwessels5158]

Its prob SPI or I2C bus telling the nexus what size battery is plugged in.

[@timg1585]

Anyone know if you can buy replacement parts for battery. It looks like the newer batteries have the BMS potted so you can't trouble shoot problem. I tested all the cells and they all measure 3.9v.

[@ThriftyToolShed]

I do not know of any where to get parts. I ordered several faulty packs from eBay a couple years ago and got some going and also had some spare cells and BMS board and connectors. BTW: On my first EGO pack repairs video I do show the process of getting out the grey potting material if interested. kzbin.info/www/bejne/e3mTeIZmnrqtsK8

[@JerryMosur]

Could someone help me please? I need a value of R126 on the control board. I want to fix blinking green light issue and started removing the potting but I accidentally knocked it off the board. Thanks in advance

[@ThriftyToolShed]

The R126 is a 10D or 124K 1% by the EIA-96 SMD standard.

[@JerryMosur]

thank you very much@@ThriftyToolShed

[@JerryMosur]

It didn't work, battery doesn't communicate with charger or any tool. No Lights. It's a shame because it still holds 50V charge. Is the a way to reset the control board?

[@ThriftyToolShed]

Unplugging the BMS and plugging it back in would be a reset on these. If you are not getting any led when the button is pressed then it could be something going on in the DC-DC converter part of the circuit. I mentioned this in some videos I know. The little square silver transformer area has some Electrolytic caps around it and I believe this is the buck converter circuit to drop down to 10VDC or so for the control circuit.

[@JerryMosur]

Thanks, I'll check them next.

[@wienst123]

Love your videos. I know this is an older video. But I figured that I would comment anyway. I'm in the process of modifying a 54" John Deere zero turn to an electric and found a guy on Ebay that is selling new Poulan electric mower motor assemblies for just $50. This comes with the motor housing and controller. I found that an Ego battery works just fine when hooked up to the Poulan controller using both the T and the D terminals. So it seems that there may be an industry standard to the communications and temperature monitoring. I wont be using ego batteries however. I'm using Lifepo4 56v 100 amp hour with built in BMS. my problem you may have guessed is the D wire. I dont have a scope to see the wave pattern/ frequency and was wondering if you have any idea of what is being generated that I could re-create to talk to 3 controllers. BTW the hrdo unit will be ran by 3000w bike motor. I would have loved to use independent gear motors for each wheel but maybe next time. Any help would be appreciated. Thanks

[@wienst123]

Sorry, i should have watched to the end before posting above comment.

[@pomonabill220]

SO it looks like the battery micro tells the power tool to shut down when the battery is low. There isn't any kind of MOSFET in the battery itself to turn off the output. Interesting! Thanks for your investigation!

[@ThriftyToolShed]

That is correct these packs have no Mosfets controlling the cut off. So more like the Milwaukee, DeWalt and Makita style of pack. They use intelligence in the tool and or communication between the two to help with low voltage protection. Where Ryobi, Ridgid (AEG) and Kobalt use the Mosfets to turn on/off the high current output. The Mosfets have to be sized for high current and will also add more heat inside the pack so I tend to like the EGO style better, but it does make the tools controllers a bit more costly to manufacture. Thanks for your comment!

[@larrywoo7055]

@@ThriftyToolShed What if you connect a generic battery (with same voltage) in parallel along with an EGO battery? this way the tool will communicate with ego battery and the generic simply adds more AH

[@ThriftyToolShed]

@@larrywoo7055 That was discussed as well. I have done this in certain situations when everything is set up almost perfectly. Not only do the packs have to be charged to the same level to be equalized they also have to be matched so they even discharge at the same rate. If not they will fight each other and it can get bad enough to damage one of the packs if not both. Some protection circuits would need to be added to be more like a battery isolator.

[@jiaoyu-zs3cf]

@@larrywoo7055 Ego seems to control the parallel connection of batteries through an external control board, similar to MOS shutdown. Control whether to parallelize each battery by assigning a set of MOSs to each battery. There is an independent MCu control

[@ThriftyToolShed]

Yes. You are referring to the Power station or the zero turn mower setup. I would surely assume so. I don't have either one, but they have to have that for sure.

[@offgridwanabe]

That D terminal should have been named P for propitiatory firmware which is what keeps EGO in business and all other battery / tool makers. Too bad we can't have some sort of standard in batteries so we could use them where we want. The bms could be replaces with a generic one so charging would not be a problem with any power supply but the tool wants to get the signal that it needs to run so that is where we should look next. I already used Snow Joe batteries to run my 36 volt lawn mower so it all works just a matter of configuration.

[@ThriftyToolShed]

I agree. That is why I did give it a good effort and I also shared the Ruzixt style replacement pack made by AMZ on my channel as well. They impressed me with at least figuring out how to copy the BMS to use it in the EGO equipment. Its not a popular option and I understand that. I bought the first replacement pack myself to see how the quality is and to test and share it on video and I recently shared a update on it because the pack has did well for me in the last year honestly. The cool thing is the company AMZ that makes the 3rd party packs has got up with me and sent the 6AH pack to look at as well. I will be testing it and sharing that soon also. I was at least able to have a conversation with the manufacture, but as far as being able to purchase the BMS board alone, they are not allowing me to do that yet, I am still hoping though....

[@offgridwanabe]

@@ThriftyToolShed Thanks for all you share it is a big deal to do all that. I guess the next step would be to try and dump the cmos chip which is where all the operating instructions are. Thanks again you have a great channel.

[@ThriftyToolShed]

Thank you!

[@wdavidson4761]

Even if we all figure out how to “just” use the dinky battery as the means to keep the tool happy and use our big li Ion ebike batteries (and maybe .22 ohm series resistor and automotive 10A fuse) to keep the dinky battery charged, then that is workable IF the BMS doesn’t freak out . May have to use 2 diodes and a summing node to prevent BMS from “seeing” the ebike battery...... I think “that’s the ticket!” What do you all think? As long as the summing nodes are done before any and all BMS, it should be completely clueless !!

[@ThriftyToolShed]

Yes, I did mention in the video that the only solution to running other packs on say the Nexus inverter would be just as you mentioned a parallel configuration with a EGO pack in place to supply the communication. Dead on!

[@jacobecorder]

I would isolate the batteries. From what I have read,connecting a dead lithium battery in parallel to a charged one would be terrible. This is why I isolate mine with the schottky diodes. Very low voltage drop You can connect the ego battery to anything you want. You will just overdischarge it without some other sort of cut off system. A relay with a low voltage cutoff circuit will handle this. Battery displays on Amazon for 30$ can handle this for you. You set low limit and it can output to a relay

[@ThriftyToolShed]

Yes, absolutely needed. Most people that watch my channel know I am so against videos telling people to "JUMP" battery to battery to "FIX" a bad pack. Such a wrong thing to do, especially in ignorance. Batteries should absolutely be either isolated from each other or almost dead on same exact voltage level and discharge rated in a tight.

[@Rendus4]

Don't worry, a bunch of electrical engineers in China haven't reverse engineered it yet, either, or else you'd see a bunch of generic Ego packs on eBay by now.

[@ThriftyToolShed]

Very true, lol!

[@jacobecorder]

I've been running this for 3 years now. My next goal is to connect to the d terminals. I'm using 4 batteries in parallell but through schottky diodes otherwise the dang things will charge each other but they would be bad. Probably blow them all up. I am using a roboclaw mcp260 controller on the drives. So I will be able to output some data to d. It's just hard because it seems to be software driven. kzbin.info/www/bejne/oXfUoKiQq7SEd6c

[@jacobecorder]

I did just get 7 ego snow blower battery combiner control boards. I am hoping to replace the schottky diodes with this. But I can't without the d terminal figured out.

[@youtubular007]

@@jacobecorder I know this is super old but did you ever solve this? I'm trying to connect 4 ego batteries in parallel to run my project but don't want to a) have an unbalanced batteries damage each other; or b) over discharge. Did those snow blower control boards work out?

[@fishinman69]

Yay lol

[@ThriftyToolShed]

I decided to show what I have learned so far. Its hard to explain how much I have looked into it and that I still do not know a whole lot about it in comments , hints the video...... I hope maybe an EE or someone with more knowledge of these microcontrollers can take it further! Thanks for your comments!