Shimano Di2 Battery Replacement/Di2 Battery Not Charging(complete strip and rebuild, cost £13.99)

Shimano Di2 Battery Replacement (complete strip and rebuild). After my Di2 battery kept losing charge, I stripped down the battery unit and tested and then replaced the 2 Litihium Ion 14430 batteries. This is a guide on how to strip and rebuild the unit. Total cost was £13.99 compared to a new Di2 battery of £135.00. The batteries in the link I have attached have soldering tabs on them in case you are concerned by soldering direct to the battery and I've shown how to test your batteries before buying new ones.
Please note that i mentioned the batteries are connected in parallel but i should have said they were connected in series
Batteries
batteriesplus....
Tools required
Small flat screwdriver
Solder iron and solder

[@LloydSmith-j5b]

Thought I’d share some extra information, when I completed this my battery didn’t work. I checked the voltage using my meter and it was all fine up to the circuit board. So, I download the old version of the Di2 software v3.4.5 onto the PC. I connected my bike to the PC and whilst I had the latest battery firmware I’m sure it did something to the circuit board to bring it back online, if that makes sense! My battery: SM-BTR2, charger: SM-BCR2. Important note the SM-BCR2 charger is the PC linking device for E-tube project software version v3.4.5, find it in the archive section of the shimano e-tube website. Thanks so much for the video Davie! Saved me some dosh…

[@pstokes9926]

I've found the answer regarding difficulty in removing the inner from a BT-DN 110a, see my earlier comment . After carefully slitting the outer case, with a Stanley knife, I was able to use a sharp pointer to prise the inner from the end of the case. I then found the a double side sticky pad was used to fix the end battery to the case. It maybe be possible by very careful drilling hole (say 3 or 4mm dia.) in the end of the case to push the inner out without the need to first slit the case.

[@waveydavielines]

Nice one! Hopefully this helps others!

[@chuckhaisley5805]

I replaced my batteries with new cells from Digikey. $3 each. I welded on my own tabs on the batteries and found the tabs and solder joints need to be tidy or the assembly won't easily fit back in the case. For $6 my Di2 is back in action.

[@ssmith954]

Excellent job -- these packs are 125 euros where I live and this is a great solution.

[@msgomg123]

Thanks Davie. Really good explanation and it needs to be. I'll give it a go with my 110 and if it doesn't work...I'll buy another. Try first, cry later!

[@grantnyenes3742]

Nice!! I’ve ordered some cells and will be doing some soldering.. mine lost all its charge after 1 ride and I’m not paying £149:-)

[@waveydavielines]

Nightmare! Best of luck with it! :)

[@darrenotoole5642]

cheers Davie . just did mine in 15 mins !!

[@cool2bdave]

Thanks so much for the demonstration. I have the same issue. Batteries ordered.

[@georgefletcher7487]

Hi and thank you for the reply. It was worth asking.

[@user-qm2jw2nh8v]

thank for your vido.I successfully revived my 6870 and saved 85＄on battery🥺

[@waveydavielines]

Glad I was able to help 👌

[@galabanker]

Wish I saw this 3 weeks back and would of saved me £165 🙈

[@waveydavielines]

Alan Laurie 😂🤦‍♂️

[@scruffygit771]

£122 from Condor Cycles :-).

[@scruffygit771]

Great vid and good to see the art of entrepreneurship isn't dead. Only 1 comment, you said the batteries were connected in parallel (at 1.25) but they must be in series if they're both 3.7v and give a total of 7.4v? If in parallel the total would still only be 3.7v. My only query is if they are in series, why have a separate 3rd wire coming off the centre connection between the 2 batteries? I can't understand what that's for....anyone?

[@waveydavielines]

Yeah, thanks for that, i'll stick a wee comment in to point that out. No idea why it needs that 3rd wire unfortunately??.

[@vanlam3892]

That's what I was going to correct him on.

[@darrylguise8493]

@@waveydavielines It may be for charging the batteries separately as the charging source is 5v.

[@wasupwitdat1mofiki94]

This information may be outlined in the documents you can find through the US Patent Office. I'm certain Shimano won't give any schematics.

[@desmosedici999]

The extra wire is so the charger can see the individual cell voltages and make sure both cells are balanced.

[@itscliffvtr]

Top job, no way I am giving Shimano £160, its just robbery.

[@waveydavielines]

😂👍

[@rubensebrechts9967]

Hello, Thx a lot I want to charge the bike for the good wheater this weekend & there where no lights on the charger and the DI2. Just ordered 2 pieces. We will try it out :-)

[@rubensebrechts9967]

Just measered the voltage in total is 7,13V so I think it's an other problem?

[@DavidStatmanlondon]

Good tips. But. Dismantling mine, find batteries were 100% despite being 4 yrs old, it was the little PCB on the pack that fried. For that there's no fix but to but a new £120+ rip-off priced pack. The E-tube confirmed the master unit wasn't visible, until the DN-110 smart battery was plugged in to the system

[@wooishen]

wow... 4 years... I just used 13 months... dry out... any secret how u maintain it???

[@RichardUttingSharpshootingUK]

Magic thanks man

[@adamcurpier]

TY for this tutorial!

[@pf465]

Great job. I love this stuff. Thank you for sharing. I'm honestly sad at the Shimano design, I think it's rubbish, but I might still buy it because SRAM has a few things that are not perfect also.

[@wasupwitdat1mofiki94]

Not to criticize but if you use a better solder iron you would get better and faster results with your welds. Using that iron you are holding the heat on the battery longer trying to get the solder to melt, that is not good for the battery. I see those batteries came with tabs on the ends. you only need to solder the tabs together between the two batteries and not try to solder the batteries together. I have experience building battery packs mainly using the 18650 cells but they are basically the same. I do appreciate you posting this video because it will save me money when it comes time to replace my Shimano battery. I will give this a go

[@waveydavielines]

Thanks for the tips! Hopefully others that plan to do this will read these too! 👍

[@ianheathcock4060]

Also that’s plumbing flux. I recognise it as I have some. It’s acid based and not the same as electrical flux (which should be built into the solder if you use the right one). Avoid using acid based plumbing solder on electronics.

[@jerrymadden6018]

Hi have a good friend going to follow up with your nollage a good video jerry

[@selinovaldes]

Thanks for the great video! I missed the part where you opened the casing to reveal the batteries. Is that on the video?

[@waveydavielines]

Sorry, it looks like I missed that part on the video! 🤦‍♂️. There is 2 little rectangular tabs at the top of the battery casing, just below where the cable plugs in. You need to push these in and then prise away the top part where the cable attaches. This will remove the whole internal unit with batteries attached. Hope this helps! Thanks, Davie

[@SuperBardley]

@@waveydavielines This fitting applies to the old, BT-110 battery, but not the new BT-110A, which has a welded case. The newer case will require careful work with a jeweler's saw or utility knife, but that leaves the question of how to hold the case together after cutting it.

[@Mowikan]

Great video!

[@pstokes9926]

Many thanks for a great video. I've have a BT-DN 110a that I am unable to remove inners. I've put forks in the groves at each end of the case and tapped these with a hammer. I've also tried gentle heat, which may release glue, but with no effect. The only thing I can now think of is carefully cutting the case. Do you have any suggestions? Kind regards Pete

[@waveydavielines]

I had a Quick Look at that one and it seems to be just a very similar design with the 2 tabs near the main connection at the opposite end from the shimano sticker. Best of luck. 🤞

[@SuperBardley]

A Reddit post noted that the A series (gray casing) has welded end caps. Will have to be cut open.

[@iknowgood2403]

Thanks for the video. I have a charger for other lithium batteries. My question is at the end of the assembled battery could one connector to positive and negative?

[@PhilB303]

great stuff, wonder if it'd work with the newere DN-110 batteries...

[@PhilB303]

i see from the below comments, that yes this'd work.

[@waveydavielines]

Thanks Phil, yeah, someone had commented below to look to try it. Good luck!

[@elmuzo5026]

Hello, I have some question about Di2 Battery connecting area. Beside cable connector (coaxial) we could see some kind of copper plate (lamella) I think it could be for "hard reset" of battery. Disconnecting cable make this late in contact with outer of coaxial connector. Right ?

[@desaipushpak]

Great video Davie... inspires me to tinker with my BT-DN110A batter pack that is no longer holding a charge. Only problem is that I am unable to source the 14430 batteries required to fit the battery housing. I was contemplating using the 14450 batteries... they have the same 3.7v but higher mAh.... in your opinion, you think this could be an issue? I was thinking of just building a new housing for the slightly longer battery if the configuration works with the chip.

[@waveydavielines]

Thanks for the comments! Im no expert but as long as the voltage is the same, this should be fine. The mAh is only the storage capacity so this should in theory give you longer between charges. The only issue you will run into is with the longer batteries, the original wiring harness may not quite fit as well so you may have to extend that. The bottom of the plastic housing could easily be cut to allow space for the longer battery and then you could tape it or make something to seal the bottom. Then you would be able to retain most of the original casing and how it connects to the top cap. Good luck! :)

[@desaipushpak]

@@waveydavielines Thank you! That's exactly how I have planned it! Will update if this works.

[@user-yi1gt1zm1q]

@@desaipushpakскажите пожалуйста, у вас получилось ? Батарея shimano заработала после замены аккумулятора?

[@francrowerypoziomerule8055]

Hello I would like to use a Shimano Alfine 11Di2 for my e-bike muscle drive part, but I don't want 3 batteries on board (so far I have 2 GreenPack to power 2 Grin AllAxle motors). I would like to know if it is possible to power Di2 differently than from the original Shimano battery? For example, using the Shimano EW-EX010 adapter normally used with Bosch systems. However, no one can tell me what the plug at the end of Bosch Y-Harness is (the one that plugs into EW-EX010) and what pinout it has. I suspect that I will have to reduce the voltage from 48V on the GreenPack to a 36V Bosch battery and I will not have a CAN to control the automatic gearshift (no cadence and speed sensors for the muscle drive). Or maybe do it differently ????

[@dg0m3s]

Davie or someone, have you managed to do the same with the newer Shimano Di2 BT-DN110 model? I am having a hard time "opening" the housing... It does not have the tabs to push in to release the housing...

[@waveydavielines]

Sorry, I’ve not had any experience with that one but looking at pictures online it does seem to have similar guides at the top near the plug connection, to line up the inner and outer case so it must pull apart. Possibly it’s been glued to seal it? If there is no obvious tabs to push in then I’d probably try heating it with a hairdryer and see if this softened any glue. If not then I’d carefully take a sharp blade to the outer casing and open it that way. You could then try to reuse the casing or just tape it all up together once fixed. Hope this helps.

[@chuckhaisley5805]

I used a screwdriver blade to pry the top out of the case. Slowly pry each side. The 2 tabs mentioned in the description don't really depress on my battery...just act as snap fits.

[@PeterKooimanNL]

I tried this, and now it doesn't work anymore. It still communicates, but it doesn't give any power anymore. 😞

[@thinksimon]

Just fried my battery. It wasn't holding charge well and I decided to replace cells. Opened it up and started to carefully peel tape. Suddenly got a whiff of smoke from the board. Put everything back - Di2 is completely dead and not charging (charging light doesn't come on). Not sure what could happen. Is it possible Shimano added some tamper protection to newer batteries? BT-DN110 from 2016 Meanwhile my bike is dead until new battery arrives... :(

[@user-yi1gt1zm1q]

Shimano ставит защиту ! Я не верю , что у автора видео получилось заменить аккумуляторы и они заработали . Пускай покажет видео , где он работает .

[@omarfiori]

Ciao. Qualcuno ha provato a ripristinare la batteria BT-DN300 ? Per aprirla avete istruzioni su come procedere? Grazie

[@antoniooliveira8444]

Bom dia dia,pode me passar o link de onde conseguiu essas bateria de 650ml

[@gvece7673]

My DN110 doesn't show up on the pce2 and when trying to charge and the light on the main charger doesn't appear. Opened up the casing and the voltage was 6.16v. Tried to push up the voltage for both and for each battery using 12v but not really moving much 6.56v. I would have thought the unit would still be recognised with 6.16v so before I start thinking about replacing the batteries, any idea if the CPU is most likely at fault? The charger is getting power to the batteries but not charging them I believe. Both batteries are over 3v.

[@waveydavielines]

Hard to say but there’s only really 2 things that can be wrong. If the PCB isn’t working then it’s game over anyway so I’d say always worth changing the batteries for how cheap it is. If you still have both batteries connected together then I think you may not get an accurate reading of each one. When I checked mine, one battery was a lot lower than the other. I recently tried to replace a friends batteries and it turned out they were both holding a good voltage but there was no shifting so that points to the PCB not allowing power through to the shifters. I’d do a full system reset first. Shane Millar (GP Lama on KZbin) has done this so have a look and follow that first before going any further. Hope this helps, good luck! 👍

[@gvece7673]

@@waveydavielines thanks for the quick reply. Think it might be PCB... Added two 18650 batteries to the existing set up, held them in place and no lights on the junction box, nor on the connected charger. I've found any component that could not be recognised as takeover I e hardware issue..

[@daabek1]

What is exactly name of batery replacement ? 14440?

[@waveydavielines]

14430

[@DarrellBrayshay]

Please let me know where to you buy the batteries

[@waveydavielines]

Think I got mine from Amazon.

[@suminshizzles6951]

I wonder if this will work the the A version of DI2 battery. As in the BT-DN110-A for the Ultegra DI2 8050 which i have. 95 pounds Sterling for what amounts to 2 rechargeable batteries is a bit steep. Thanks for this. I bet the battery suppliers listed are happy. On their site they say in the description that this is for 6870 Ultegra though.

[@waveydavielines]

I can’t see there being much difference to be honest. If it’s not working anyway then you can’t make it worse by trying.

[@scruffygit771]

Yup, this will work with the DN110 as well. The BTR2 and DN110 are exactly the same voltage and power output. The only difference in the two are that the newer DN110/110A batteries contain a memory chip for synchronized shifting customisations. The internal batteries themselves are the same so Davie's hack will work no problem.

[@davidturton8713]

How did you take battery apart

[@waveydavielines]

@@davidturton8713 Sorry, i only just noticed this reply! The plastic housing presses in with a small screwdriver on two clips at the top and then I used a stanley knife to slice the solder clips from the battery.

[@kengray7152]

Can anyone help, problems with Di 2. After testing the battery., pressing the lever, solid green light comes on followed by the red three seconds later, green and red lights are on together. What does that indicate? Rear mec is working but front mec isn’t,t . Battery is showing 7.5v . Can anyone help

[@wasupwitdat1mofiki94]

Your battery is low if the front mech doesn't work but the rear mech does. Shimano manual explains this. It's a feature designed in to the system so you're not completely stuck out on the road.

[@ProstoNickSam]

after replacing the batteries, unfortunately, the whole assembly stopped working :(((

[@alebart2493]

Writing here because I haven't found any help on the internet I replaced the cells in a battery that stopped holding charge for more than 24h. Essentially, I did the exact same job as shown in this video. The problem is that the di2 system pretends my battery is dead despite it being charged. I can charge the battery with the normal di2 charger, everything seems fine. But when I try to shift, the junction box blinks 5 times red - meaning the battery is dead. Except it isn't, both cells are at 4.2V My guess is that the microcontroller of the battery decided it was dead (either for safety or just to stop you from repairing it, Apple style) and refused to change gears, since a big part of the brain of the di2 system is in the battery I tried updating the firmware of the battery using the SM-BCR-2. I hoped that updating the firmware would "reset" the battery, but while I managed to update it, it still refused to power the system Also worth noting, the shifting works when the charger is plugged in, but won't if the charger is plugged in but not the battery. So I know the battery can physically work but won't

[@user-yi1gt1zm1q]

Все верно ! Замена не поможет , так как shimano встроило в сип защиту . Я не верю , что те люди которые поменяли внутренние аккумуляторы, что у них получилось . Нужно менять и чип .

[@christophercondron5388]

Just out of curiosity how long does a battery pack normally last does anybody know

[@goldreserve]

My 2nd battery just died, last about 18 months. Probably water damage. Be careful of rain entering the frame.

[@christophercondron5388]

@@goldreserve thanks for the reply my battery is in my frame of the seat post. I'm pretty confident it's a waterproof place

[@georgefletcher7487]

Hi are you open to refurb my batteries ? I will pay obviously. Please get back to me when you can. Regards George

[@waveydavielines]

Hi George, sorry bud, its not something that i would like to do unfortunately. Hopefully you can find someone though. Cheers, Davie