Replacement firmware for Dyson V10 Batteries - Page 1
Forum section: electronics / projects

author: davidmpye
author_rank: Contributor
timestamp: July 20, 2023, 09:00:02 pm
content: Hi!I've been working on producing a from-scratch firmware replacement for the Dyson V10 vacuum cleaner battery packs.Why?Well, because the original firmware on these boards permanently disables the pack when the cells fail/go out of balance, and even if you replace the cells, the BMS won't ever work again as it stores an error code in its' internal flash.I've managed to produce replacement firmware which mimics the functionality of the existing one, including a serial connection to the vacuum cleaner which tricks it into thinking it's talking to a genuine original pack.This is available under the GPL v3, athttps://github.com/davidmpye/V10_Dyson_BMS/In summary:What works: Charging and discharging are supported, and it can communicate with the vacuum cleaner so it powers up.What doesnt: I haven't implemented temperature protection yet, so while over/undervoltage are catered for, the temperature of the pack ISNT currently monitored.At the moment, if you'd like to try it you will need: Microchip Studio (free download) and an SWD programmer that Microchip Studio supports (eg ATMEL ICE, though other CMSIS-DAP compliant programmers might work too - please let me know if they do!)I've produced basic flashing instructionshttps://github.com/davidmpye/V10_Dyson_BMS/wiki/FlashingIt is possible to flash it using a Raspberry Pi and its' GPIO headers directly as well, but this requires a modified version of OpenOCD and some other hackery to get the Security Bit disabled from the MCU. In time, when the project is more complete, I will be able to produce SD card images which will auto-flash the packs to make things more accessible :-)If anyone fancies collaborating/testing etc, please do let me know :-)David

author: rulof
author_rank: Contributor
timestamp: July 21, 2023, 07:51:19 am
content: good afternoon, thank you so much for your work.I flashed using j-link v9. the battery came to life. I will conduct tests.after that, I counted through J-Flash 7.84., I can upload here a file for firmware using J-Flash V7.84. and j-link v9.

author: davidmpye
author_rank: Contributor
timestamp: July 21, 2023, 03:12:47 pm
content: Hi, that's great to hear. Please let me know how you get on - does it charge and operate the vacuum ok?When you unplug the charger it should give you short flashes (1 flash is 50mV) to tell you how unbalanced the pack is.CheersDavid

author: rulof
author_rank: Contributor
timestamp: August 14, 2023, 08:43:49 am
content: i have jlink v9 can you give me the firmware file, my damn dyson v10 just broke the battery today, thank youthis is not the final version. but the vacuum cleaner works with it.

author: davidmpye
author_rank: Contributor
timestamp: August 14, 2023, 08:46:19 am
content: Hi,Current version has quite a few improvements including error codes so you can work out what's wrong, as well as temperature monitoring.I can supply a binary but seeing as you'll need Microchip studio as a free download it's only one extra step to download the project and compile it yourself.Www.github.com/davidmpye/V10_Dyson_BMS/wiki/FlashingPlease do let me know how you get on!David

author: rulof
author_rank: Contributor
timestamp: August 14, 2023, 10:13:42 am
content: here is the file from the new version. I tried the new version. on charging error 6. tell me what it means?

author: davidmpye
author_rank: Contributor
timestamp: August 14, 2023, 11:31:20 am
content: Hi!Thanks for testing! Are you getting 6 red flashes when trying to charge? If so the error is BMS_OVERVOLT tripping the BMS chip. Are you using a Dyson charger or a PSU? I would suggest checking the supplied voltage and if a PSU, try lowering it a little? I haven't seen this with mine yet....This might have been happening to you before but the firmware wouldn't report it.Let me know.Thanks,David

author: davidmpye
author_rank: Contributor
timestamp: August 14, 2023, 11:56:40 am
content: Just realised, if you are using a psu and not a Dyson charger, you'll need to let the pack to go to sleep (60 seconds) before trying to charge again, as I've just noticed the error state isn't getting cleared properly. Will fix that tonight....David

author: rulof
author_rank: Contributor
timestamp: August 14, 2023, 12:42:36 pm
content: I use the original dyson charger. there were no problems with charging before.

author: davidmpye
author_rank: Contributor
timestamp: August 14, 2023, 12:58:00 pm
content: I see. That shouldn't be happening then. I'll run some more tests tonight and see if I can replicate it. Can I confirm : 6 red flashes when you plug in the charger?David

author: rulof
author_rank: Contributor
timestamp: August 14, 2023, 01:10:31 pm
content: the battery is almost charged. when the charger is connected, it starts charging. after about 20 seconds, the error 6 red flashes. if you disconnect the charger, the error will be reset. but when connected, everything repeats.

author: davidmpye
author_rank: Contributor
timestamp: August 15, 2023, 08:16:35 am
content: OK, thank you both for the reports.I'll try to make an update in the next day or two and produce a new version for testing, if you don't mind!I will adjust the overvoltage settings and delay times for them, as well as the error handling. I have a 'clone' Dyson charger, and my pack doesn't hit this issue, but it's possible the Dyson original charger is a bit more aggressive.Cheers,David

author: sneek
author_rank: Newbie
timestamp: August 16, 2023, 11:37:13 am
content: Wow, impressive work!I have a Dyson v11 (the swapable kind if that matters) that is not indicating any sign of life. The V11 battery board looks quite similar to the V10 so I'm thinking of giving this a try. I think the modelnumber on the board is367051-01/04(I've already pulled out the cells and measured them and they showed being ~400mV. Me being stupid thought it would be enough to revive or swap the different cells but apparently not.)So I have no programmer but a spare raspberry pi just laying around. The modified OpenOCD version you are talking about, are there any information about it online so I can read about it and try it out? If not that's alright, I can wait til you release the SD card image. I don't want to add any burdens on you!Thanks,sneek

author: davidmpye
author_rank: Contributor
timestamp: August 16, 2023, 03:01:46 pm
content: Hi Rulof and Quy,Thanks for your feedback so far - I have updated the firmware on github to set a slightly more forgiving 4250mV overvolt trip, which I hope might fix your 'flashing red' fault.Would you be able to test for me please by redownloading and building in MC studio? I'd really welcome your feedback!Thanks again,David

author: davidmpye
author_rank: Contributor
timestamp: August 16, 2023, 03:03:42 pm
content: Hi Sneek,I've not had a V11 battery to play with but looking at the photos, I am not convinced it will work at all.There don't appear to be any LEDs (?), or at least, certainly not the same arrangement in V10, and also I suspect Dyson have updated the serial 'handshake' between the battery and the vacuum, so even *IF*, and it's probably a big IF, everything else was the same, I doubt it would just work.Are you able to identify the BMS chip, and the MCU? I can't tell (because of dyson glue!) whether it's the same BMS / MCU.CHeers,David

author: sneek
author_rank: Newbie
timestamp: August 16, 2023, 05:01:30 pm
content: Oh, that's a bummer!It does have two small SMD LEDs on each size of the board.MCU is anATSAMD20 E15B-U.I can't decipher the fifth character on the BMS but the others are BQ769?003 so I guess the BMS is aBQ7693003.Thanks,sneek

author: rulof
author_rank: Contributor
timestamp: August 17, 2023, 07:36:13 am
content: Quote from: sneek on August 16, 2023, 05:01:30 pmI also tried downloading the firmware to dyson v11.the LED blinks when turned on. the vacuum cleaner does not turn on. when the charger is connected, the LED also blinks, charging does not start.

author: davidmpye
author_rank: Contributor
timestamp: August 17, 2023, 11:29:35 am
content: Disappointing but not surprising. I suspect Dyson have changed the Comms protocol but it sounds like it might be possible to produce a v11 firmware but would need a cleaner and a working pack to try to reverse engineer the protocol....Did you have a chance to see if the updated v10 solved the red flashing issues, rulof?David

author: rulof
author_rank: Contributor
timestamp: August 17, 2023, 01:42:28 pm
content: Did you have a chance to see if the updated v10 solved the red flashing issues, rulof?Davidchecked it out. it seems that the problem has been solved, after charging is completed, the indicator stops flashing.there is one nuance, when it is almost charged, it flashes strangely. I made a short video.

author: davidmpye
author_rank: Contributor
timestamp: August 18, 2023, 09:53:25 am
content: Hi Rulof,This was deliberate - the quick red flash was used to indicate that the charge had paused because a cell had hit target voltage, and was waiting for 30 seconds to see if it stabilised at a lower voltage, and if charge could then be restarted.I think it is probably confusing, so I have updated the code to remove that feature now, if you wanted to update again!Thanks for the feedback :-)David

author: davidmpye
author_rank: Contributor
timestamp: August 19, 2023, 09:52:24 pm
content: Another project update!Got the images generated to flash the BMS using just a Raspberry Pi (Any Pi or Pi Zero should work just fine). No programmer needed.Have a read ofhttps://github.com/davidmpye/V10_Dyson_BMS/wikiand ask me any questionsDavid

author: davidmpye
author_rank: Contributor
timestamp: August 22, 2023, 08:18:21 am
content: Hi,It is available as the .elf file from the project releases page.Do let me know if it fixes that problem.CheersDavidhttps://github.com/davidmpye/V10_Dyson_BMS/releases

author: davidmpye
author_rank: Contributor
timestamp: August 22, 2023, 02:22:35 pm
content: Hi quy,thanks for letting me know v10 is now fixedI haven't ever tried a v11, so I am not surprised that the firmware would need adapting to make it work properly on v11.. Sorry!If somebody fancies lending me a couple of v11 packs and a clearner, I'll see what I can doDavid

author: rulof
author_rank: Contributor
timestamp: August 26, 2023, 11:08:14 am
content: Quote from: davidmpye on August 22, 2023, 02:22:35 pmI would love to send you v11. but it's almost impossible from my locality. maybe I can run some tests? and provide you with information?

author: davidmpye
author_rank: Contributor
timestamp: September 05, 2023, 02:37:16 pm
content: Hi Rulof,Alas I think that'll be difficult, just because of the amount of hacking about that'll be needed to get it working.If I can find a V11 somewhere cheap on ebay over here, i'll see if I can pick one up for the challenge....David

author: suenbrad
author_rank: Contributor
timestamp: October 21, 2023, 02:21:57 pm
content: davidmpye Hello: I would like to ask you for advice. I followed the instructions in the article you published and used Raspberry Pi to complete all the procedures. Now the battery pack has changed from a red light to a blue light. I don't know how to proceed with the next procedure. Can you teach me how to proceed with the next step, because I really want to Save the unusable battery pack. Thank you for sharing the article. It makes me full of hope that the battery pack can be saved.

author: davidmpye
author_rank: Contributor
timestamp: October 21, 2023, 03:45:17 pm
content: Hi,What next step are you looking for?Does it work in the cleaner?David

author: suenbrad
author_rank: Contributor
timestamp: October 21, 2023, 11:31:08 pm
content: I hope the battery can be used normally. At present, it only flashes blue light and cannot operate when the vacuum cleaner is installed. I only use the Raspberry Pi to update the firmware. I don’t know which aspects still need to be cleaned to completely solve the battery problem.

author: davidmpye
author_rank: Contributor
timestamp: October 22, 2023, 07:44:22 am
content: Hi,Does it charge if you connect the charger? (Flashing blue segments until all 3 light)A good next step would be to check the voltages of each cell with a multimeter.Does the red led flash at any point and if so, how many flashes?David

author: suenbrad
author_rank: Contributor
timestamp: October 22, 2023, 12:36:07 pm
content: It won't charge when connected to the charger, and the red light will flash twice.Please tell me what procedures I need to perform after refreshing the firmware using Shumei Pie, so that the battery can be successfully unlocked!

author: davidmpye
author_rank: Contributor
timestamp: October 22, 2023, 01:40:57 pm
content: Hi,I would use a multimeter next:Check the voltage of each cell in turn.When you push the black button, check the voltage that appears at the two battery terminals.Let me know what you find.David

author: suenbrad
author_rank: Contributor
timestamp: October 22, 2023, 03:27:17 pm
content: I used an ammeter to measure the voltage of each battery, and it was probably between 4.03v and 4.07v. When I pressed the black button, the meter measured that there was no voltage output at the battery's output terminal.

author: davidmpye
author_rank: Contributor
timestamp: October 22, 2023, 03:41:47 pm
content: Hi,Is there any red flash code when you press and hold the black button?If there is a pack fault the red light should flash a sequence to explain whyDavid

author: suenbrad
author_rank: Contributor
timestamp: October 22, 2023, 03:48:52 pm
content: Press and hold the black button, the blue light will keep flashing, but there will be no voltage output.I have other faulty v10 batteries here. I will try another one and see what happens before I report it to you. Thank you for your help.

author: davidmpye
author_rank: Contributor
timestamp: October 26, 2023, 01:20:51 pm
content: Hi,If you have access to a USB-serial converter, let me know.The next firmware release will print debug output via a second serial interface, so you can see what the pack firmware is doing.Unfortunately, sometimes the problem is a fault in the battery management IC (eg it cannot read voltage of one cell etc), which is a problem :-(David

author: Kamiyama
author_rank: Newbie
timestamp: November 04, 2023, 09:53:27 pm
content: Hi David. Assume job!How I can modify charge and discharge over current? Useful, if using this bms not in vacuum cleaner...Thanks!

author: suenbrad
author_rank: Contributor
timestamp: November 05, 2023, 11:20:40 pm
content: Hello, yesterday I took another faulty V10 battery and refreshed the firmware you provided through the Raspberry Pi. It finally turned on the blue light I had been waiting for for a long time. Pressing the black button can start the vacuum cleaner normally and charge normally. After charging, the special thing is that before the battery goes to sleep, there will be a very colorful light flashing once and then going out. Thank you very much for your assistance in getting my battery back to normal. Very happy, thank you.

author: Samlivas
author_rank: Newbie
timestamp: November 15, 2023, 05:20:12 pm
content: Hi. I have a problem with the V10 battery every 2 years. My plan is to make a new battery. Might be 3-5Ah or so. Do you know how to cheat and start a vacuum with non original battery? It has 2 comunication vires. What kind of ''food'' needs to be given to my Dyson v10? to start it. Spasibo

author: davidmpye
author_rank: Contributor
timestamp: November 18, 2023, 02:52:45 pm
content: Quote from: Kamiyama on November 04, 2023, 09:53:27 pmHey,Good question - you can modify voltage limits for cells in the config.h file:https://github.com/davidmpye/V10_Dyson_BMS/blob/main/V10_BMS/src/config.hAt present, I haven't moved the current limits to config.h, but that could certainly be done with a small amount of effort.At present, they are hardcoded in:Specifically, in the enable_discharge function:https://github.com/davidmpye/V10_Dyson_BMS/blob/main/V10_BMS/src/bq7693.cvoid bq7693_enable_discharge() {bq7693_write_register(SYS_CTRL2, 0x40); //CC_EN=1bq7693_write_register(SYS_CTRL1, 0x18); //ADC_EN=1, TEMP_SEL=1bq7693_write_register(PROTECT1, 0x9F);bq7693_write_register(PROTECT2, 0x04);uint8_t scratch;bq7693_read_register(SYS_STAT, 1, &scratch);bq7693_write_register(SYS_STAT, scratch); //Explicitly clear any set bits in the SYS_STAT register by writing them back.//DSG_ON turns the discharge FET on.bq7693_write_register(SYS_CTRL2, 0x42);//CC_EN, DSG_ONbq7693_write_register(PROTECT2, 0x04);bq7693_write_register(PROTECT1, 0x82);}The values written into PROTECT1 and PROTECT2 set the discharge overcurrent and short circuit delays and limits. I don't think there is actually a charge current limit - you can measure it using the charge countYou'd have to reference the BQ7653 datasheet (https://www.ti.com/lit/ds/symlink/bq76920.pdf) and change the values appropriately for your applicationDavid

author: davidmpye
author_rank: Contributor
timestamp: November 18, 2023, 02:58:32 pm
content: Quote from: Samlivas on November 15, 2023, 05:20:12 pmHi,It might be worth re-using the BMS board with my firmware, and replacing the cells? Up to you!Either way, the comms required are serial data at 115200 baud. I *THINK* from memory that it actually uses the VBAT full pack voltage as serial V-high and pulls it down via a sizeable resistor/transistor combo, but you'd want to check that with an oscilloscope to mkae sure I'm right!The actual data content is here:https://github.com/davidmpye/V10_Dyson_BMS/blob/main/V10_BMS/src/serial.cEach packet gets sent around 50mS intervals - it doesnt seem critical.Alas, other than a few bits of information I figured out via snooping the serial data, I don't really know what the MEANING of the data inside those packets are, only that the cleaner insists on receiving them if you want it to work....There are a couple of packets that are useful to interpret, from the cleaner to the pack, to enable it to show LED statuses for BLOCKAGE, and NO FILTER. However, you might or might not want to bother with that functionality.With the above information, it should be possible to make a mains adaptor to run the cleaner off the mains directly, or even to make an 'adaptor' letting you connect other 7S packs to the cleaner, if anyone really wants!David

author: rulof
author_rank: Contributor
timestamp: December 01, 2023, 11:01:58 am
content: I'll ask you again. maybe there are already options with V11? I have 3 batteries lying around. I want to revive them.

author: turenabo
author_rank: Contributor
timestamp: February 21, 2024, 09:06:37 am
content: hi David, great job, thanks, I am a beginner of learning BMS and I found your project on github when I try Tinfever's V6/7 BMS project. You mentioned some functions are still not implemented, will you go on this project and release new firmware? I would like to learn from this.I got a MPLAB IDE and a PICkit3 when I learn V6/7, what should I prepare for V10? You have a very good idea is to use a raspberry pie to burn the firmware, but I don't have this, do you recommend to buy a raspberry or to buy an ATMEL tool?many thanks

author: volshebnik12345
author_rank: Newbie
timestamp: March 05, 2024, 10:33:48 am
content: Hello everyone Has anyone compiled a firmware V10 BMS file from dear David Moyes? I want to try to flash the controller using a programmer, can you share the bin firmware file?

author: turenabo
author_rank: Contributor
timestamp: April 21, 2024, 11:22:58 am
content: Hi David, I saw in the firmware operation on your github that your firmware has LED code with high and low temperature protection. I saw here that you said there is no temperature protection. I am not sure whether there is temperature protection?

author: Tony1s
author_rank: Newbie
timestamp: September 16, 2024, 11:32:24 am
content: HiNew here, having only recently learned about the cruel behaviour of Dyson in locking out their batteries.I have dismantled one sv12 battery, all cells between 4 and 4.2 v (I could probably rebuild it), and have another untouched one in reserve, both had red led syndrome. I caused the first one to lockout by discharging cells to asses their capacity, unsuspecting of the vms behaviour. The 2nd one was in storage for about 2 years, prolly self discharged?I don’t have a pi to use as a reprogrammer (yet) , anyone done the same thing with an aurdino?

author: Tony1s
author_rank: Newbie
timestamp: September 25, 2024, 01:47:36 am
content: Hi thereHoping there is someone in here who can help me with some debugging of the pi programming method.Purchased a pi 4 (wanted one for other tinkering anyway) and downloaded the imageTopped up the 7 Dyson cells manually , and made connections between the Dyson battery and the pi as per the wikiHowever, on pressing the black lever on the battery pack (and getting a flashing red led), and powering up the pi, all I see on screen is a repeating pattern of restarts and firmware not found messagesI am brand new with raspberry pi, so don’t know enough to decode what else is being shown to me on screenAnyone got any clues?I have access to an oscilloscope so if I knew what to look for, could look for activity on the reset and data pins.Any help appreciated

author: Tony1s
author_rank: Newbie
timestamp: October 13, 2024, 07:36:18 pm
content: Bump…Can anyone who has successfully replaced v10 Dyson firmware with the raspberry pi method comment on the screenshots above ? Any clues what I should try next appreciated.

author: Tony1s
author_rank: Newbie
timestamp: October 24, 2024, 04:46:50 am
content: Updating my findings in the hope,it will help others on this journey.When programming your pi card, you can’t just file copy the supplied image file to the sd card, you need an image writer program to do that. I used the one from raspberry pi. That got the pi to boot up properly, however it failed to find the battery firmware . I found it necessary to connect the 3.3v between pi and battery pack, THEN it found the firmware and reprogrammed it, culminating in a success message.Sadly, so far, the battery pack is still not working though, now it flashes a blue led instead of a red one, but it doesn’t produce an output voltage when you trigger it, and it doesn’t appear to charge. I note a previous poster found the same thing. Like him, I have a second battery pack to try….

author: Cslim
author_rank: Newbie
timestamp: February 23, 2025, 05:46:51 pm
content: Hi, new here. Tried the Raspberrypi approach on my v10 battery. Unsuccessful. The red led did flicker but battery remains dead.Possible that dirty Dyson changed some features to defeat Davidmpye's valiant effort.

author: Tony1s
author_rank: Newbie
timestamp: March 04, 2025, 03:17:41 am
content: Summarising my findings. Whilst I successfully replaced firmware in 2 Dyson battery packs using this process (the pi one), it turned out at least two of the cells were stuffed in both of the packs I was working on. Sad, but a bit terminal. I did experiment with transplanting cells, but I damaged the board in the process, as although the cli said all was well and the vacuum SHOULD run, it didn’t actually crank up.The whole vacum was a bit tired anyway, with cracked a broken plastic bits , so I retired the whole idea .Thanks to the OP for the original idea and encouragement.The learning point here, is don’t accept manufactures that build in planned obsolescence.

author: Ainarssems
author_rank: Newbie
timestamp: May 29, 2025, 12:36:43 pm
content: When my V10 pack got weak and did not last in Max mode, I replaced Molicel P26A cells with P28A without any issues. A year or 2 later these have gotten weak as well not lasting in Max mode so replaced them again with P28A. But this time I got red flashing light on battery after change flashing 20 times. Only thing different was that first time I just replaced batteries as they arrived, this time I charged them before replacing. Any ideas?

author: Cslim
author_rank: Newbie
timestamp: May 31, 2025, 02:41:35 am
content: The best way to defeat Dyson is to just defeat all the electronics in Dyson motor. Just use the hall sensor and supplied the right current to the two poles of the motor. A switching waveform to the motors using the hall sensor. Then just use any battery pack with the right voltage. No Bms needed for the battery.

author: Ainarssems
author_rank: Newbie
timestamp: May 31, 2025, 12:24:41 pm
content: Just to follow up on my previous post.First of all big thanks to davidmpye for the custom firmware, this has now resolved the issue.Here is the complete history:1. Bought Dyson V10 in August 2021 on eBay from the official Dyson outlet as refurbished. Looked brand new without any scratches, marks, dust or dirt. I assume it was new/unused old stock just repackaged in plain packaging just to shift more units without reducing standard price or introducing big discount which could undermine RRP and future sales, and less warranty commitment. But it could have been used battery or unused battery that has been sitting for long time.2. By August 2022 battery was only lasting about 1 minute instead of original 6 min in Max mode and we do use Max mode quite a bit. I don't know what the Low mode can be used for, Mid setting is OK when using motorised brush but for any open ended sucking without motorised brush it's useless and even in Max mode is just OK, not great.3. So I ordered aftermarket replacement battery from eBay, this was lasting longer than used OEM battery in Mid and Low but was unusable in Max only lasting around half a minute, less than the old used OEM battery. So it was returned.4. Opened up battery and measured voltages to see if any of cells were low but all they were pretty even so I ordered new Molicel P28A batteries to replace original P26A cells and replaced them. Replacement went OK without any issues. I did not have charger for 18650 cells at this time so they were not charged or balanced before putting in battery, they just went in as shipped.5. Fast forward to 2025, almost 3 years later and the replacement cells are not lasting that long now as well on Max mode, so needed replacing again. I still had P28A cells from 2022 as I had to buy more that time to reach minimum order value from wholesaler, I had bought 20 cells at that time from wholesaler for less than it would cost to buy 7 cells from a low quantity/value retail seller. Since I had the cells already I used P28A, if I had to buy again I would have chosen P30B6. This time I have the charger so I charged the cells to 100% before putting them in the pack, I assembled the pack and it does not work, just getting 20 flashes of red LED so I am thinking;a) Dyson only charges cells to around 4.1V an me putting in cells charged to 4.2V have triggered overvoltage fault but unlikely:b) more likely that first time replacing cells BMS was off and I did not wake up it until all cells were replaced, on the second time I may have accidentally pressed the button while changing cells and started up BMS which registered balancing error due to some cells being 4.1 or 4.2V and some cells not connected reading 0V.5. Got myself Raspberry Pi Zero 2 W, connected 4 wires without 3.3V, tried to flash it and unsuccessful. I see Tony1s had the same issue without 3.3V so I also connected 3.3V and was successful this time. I think BMS has it's own 3.3V and it works on faster PIs, but with slower PIs, BMS times out and goes to sleep/turns off and cuts 3.3V before PI boots up and tries to flash ne firmware.PS: When I replaced cells first time, battery was fully charged using Dyson charger and all voltages were close so I ruled out it being single rouge cell and replaced all. Second time all voltages on fully charged cells were even again 4.094-4.097V. But since now I have charger for 18650 cells, I did run some tests on them. The unused replacement P28A cells that I bought 3 years ago were 15-22 miliohms at around 30% and capacity 2530-2588mAh, the P28A cells that came out of pack were 18-26 miliohms at around 30%, 6 cells were 2100-2250 mAh on first test but one cell was only 856 mAh. I ran several additional charge/discharge cycles on that cell and it recovered to 1903 on second run and then 2066 and 2133. So I may have been OK just running some full charge/discharge cycles on the single weak cell and reusing all 7 cells that I put in almost 3 years ago.

author: lampik
author_rank: Newbie
timestamp: June 03, 2025, 10:41:15 am
content: i Can Join to tests i got a sv28 v11 battery after disasembly and stopped working/flashing

author: lampik
author_rank: Newbie
timestamp: June 03, 2025, 11:10:51 am
content: i can help with tests too, so im here

author: rulof
author_rank: Contributor
timestamp: June 04, 2025, 07:47:24 am
content: Quote from: lampik on June 03, 2025, 11:10:51 amthere is no firmware for v11 yet. Can you count the old one from your battery?