[DIY] Spare Battery for JollaC
 

Hi everybody,

as there is no spare battery available for the JollaC outside of India.

I wrote a short tutorial on how to make the UMI X2 battery JollaC compatible. A big thanks to TJC user Giacomo Di Giacomo who gave the tip in the spare battery thread that it fits the JollaC.

Warning: Your warranty will be voided. And you could destroy your phone with this guide. I am not responsible for any damaged phone. And don't point a finger at me if you failed to solder everything properly.

Please only do this DIY if you know what you are doing. If you never used a solder iron before please DO NOT DO IT!!! The battery could explode if it gets too hot.


What you need:
- UMI X2 battery (http://www.ebay.de/itm/Akku-fur-UMI-...oAAOSw9N1Vjsqg)
- soldering iron (best with a thin tip)
- tin-solder
- scissors
- pencil
- heat shrink tube or any other isolating material which fits around the battery
- cable stripper
- thin cables (black, red, yellow)
- adhesive copper foil (https://www.amazon.de/Kupfer-Heizung...dp/B017LB9AJW/) or any type of copper, brass
- a vice or something to hold your battery
- multimeter
- A table with good light
- patience

Let's begin
First of all prepare all the stuff you need. It's annoying if you need to search for things during the work.

http://i.imgur.com/yf8PnSN.jpg

To make placing of the copper foil easier, we mark the positions of the contacts with a pencil using the old battery.

http://i.imgur.com/qjX4U3q.jpg

Extend the markings to the top of the battery.
http://i.imgur.com/PR18dET.jpg

Skin the cables and prepare them with tin-solder. Also cut the skin ends to a suitable length.
http://i.imgur.com/xHFvh5q.jpg

Put your battery in a vice, but don't use too much force!
http://i.imgur.com/2MOSUAA.jpg

Prepare your solder iron with a thin tip and set the temperature to 400°C.
http://i.imgur.com/x8e7asG.jpg
http://i.imgur.com/ep12aOA.jpg

Prepare the battery with a bit of tin-solder (makes it easier and faster when you attach the cables).
http://i.imgur.com/pts67MU.jpg

Attach the cables (black -, yellow charging, red +).
http://i.imgur.com/d71NA80.jpg

Cut the copper foil that it fits your markings. And 3 different lengths, make sure that the longest copper strip is outside facing.
http://i.imgur.com/ojnPJWO.jpg
http://i.imgur.com/dctgCLz.png

Solder the cables to it, use your old battery to check if your contacts are in the right order (minus is the outside facing contact). Make sure that the cables don't cross each other, otherwise you will get a bulge in your backcover.
http://i.imgur.com/caMWYxw.jpg

Check the contacts with your old battery and a multimeter. If the multimeter shows approx 3,8V between + and - aswell as + and yellow everything should be alright.

Place the battery in your phone to check if everything fits or if you need to adjust something.
http://i.imgur.com/5ySQZ5Z.jpg
http://i.imgur.com/ABabYxO.jpg

If everything fits and you are sure that you have the cabling correct. Try to power on the phone.
http://i.imgur.com/1NOA3X8.jpg

If that worked you can apply the heat shrink. Make sure that you isolate the original contacts of the battery.
http://i.imgur.com/vVtaODc.jpg
http://i.imgur.com/L1Ih6a6.jpg
http://i.imgur.com/3kTXD5J.jpg

Finally check if your phone charges.
http://i.imgur.com/RyrgBA1.jpg

If you did a good job and used thin cables the cover does still fit and does not have a bad bulge. Mine has a small one not really noticeable (at least better than my thickened battery ;)).
http://i.imgur.com/94w3mTL.jpg
http://i.imgur.com/LmQX8xr.jpg

Screenshots of CSD Tool after the fix (phone was charging that's why the discharge test fails):
http://i.imgur.com/Qc5ZzsH.jpg
http://i.imgur.com/Hn1QbA6.jpg
http://i.imgur.com/76KXApO.jpg

You can check these things via CLI too:
http://i.imgur.com/DvCUEgw.png

Re: [DIY] Spare Battery for JollaC
 

Very detailed tutorial, lovely! :D

Re: [DIY] Spare Battery for JollaC
 

Giacomo posted a picture at together.jolla
https://dl.dropboxusercontent.com/u/...01-04-0612.jpg
Nice work I'd say.

Re: [DIY] Spare Battery for JollaC
 

Yeah, I know (that's why I linked the thread and mentioned him ;)). But some users wanted a more detailed report on how to do that. Not only a picture of the result :).

Re: [DIY] Spare Battery for JollaC
 

Added screenshots of CSD-Tool.

Re: [DIY] Spare Battery for JollaC
 

I think CSD tests give nothing more than: it works. More interesting would be voltage drop on this tiny wires under heavy load or charging ( > 1 A), especially looking at Giacomo's mod.

Re: [DIY] Spare Battery for JollaC
 

You can draw more current than you would expect through those cables.
https://learn.adafruit.com/wires-and...ns/wire-guages

And did you see the contacts which connect to the battery? Much smaller than any of the cables used by me or Giacomo.

Re: [DIY] Spare Battery for JollaC
 

Started a short load test with stresser.

stress-ng --cpu 4 --timeout 60
http://i.imgur.com/9dhBcHC.jpg

Voltage drops not more than with original battery. (4082 mV to 3906mV)

Re: [DIY] Spare Battery for JollaC
 

There is spare battery available in India, but it wont ship oversea

Re: [DIY] Spare Battery for JollaC
 

That's what I wrote in my first sentence ;).

Re: [DIY] Spare Battery for JollaC
 

Thank you very much for your detailed tutorial! I think I'll try it as well, just hope I won't fry my Jolla C in the process :)

Could you please point me to it? If you mean the maxbhi site, it is sold out and judging from the 0% fulfillment ratio and fake reviews from 2014 (Intex Aqua Fish was released in the summer of 2016 and all the reviews are dated earlier), it looks like it never was available.

Re: [DIY] Spare Battery for JollaC
 

what a hack... isn't it easier just to resolder top from jolla battery to other one than "move" pins to different position???

Re: [DIY] Spare Battery for JollaC
 

Nice DIY tutorial you made there MaemoUser ;)

Re: [DIY] Spare Battery for JollaC
 

I don't think this is easier as there are electronics hidden behind the top (temperature sensor). So I would say this is the "best" solution to get the contacts to the matching site.

And it's more dangerous for the average people as you need to really watch your temperature because you are soldering directly at the battery. You also need much better equipment with even finer tips for the soldering iron. And you could destroy both batteries while doing so. Especially when one is already in a bad condition I wouldn't touch it with heat. Or open it in any way.

The old battery:
http://i.imgur.com/IqlRfTP.jpg
http://i.imgur.com/rI3OxOg.jpg

Re: [DIY] Spare Battery for JollaC
 

According to the import-export data base 300 spare batteries entered India in August, so there seems to be some around. But apparently not for sale over internet.

Re: [DIY] Spare Battery for JollaC
 

Guys, small question... why not to use only adhesive copper foil instead soldering wires ?

Re: [DIY] Spare Battery for JollaC
 

Why indeed.

I can see at least two reasons. One, the contacts are in the wrong order and the wires need to cross. Not impossible to do with copper foil (after all, all you need is a layer of sticky tape for isolation), but easier to do with wires, which you are better off doing anyway for reason two, you need to solder to the battery's original contacts. An adhesive copper foil does not make such a good and reliable connection, if it makes any at all.

Re: [DIY] Spare Battery for JollaC
 

Thanks...
1. We can use both sides of battery to put the foil (or i'm wrong ?) In this case we have only one cross of foils that can be isolated with small patch of something..
2. About bad connection of foil, I will check when I will get my new battery.

Re: [DIY] Spare Battery for JollaC
 

in heavy use phone can use 1A or similar, and your foil will heat so much and can damage phone.

Re: [DIY] Spare Battery for JollaC
 

I thought about heating, but didn't was sure... Probably you are right and we need wires... that's all...
My original battery is terrible, really bulky, hope it will not explode before I will get new battery :D

Re: [DIY] Spare Battery for JollaC
 

That is not an issue. PCB traces (and other copper foils stuck to surfaces) are capable of carrying more current than wires of the same cross-section area because the surface they adhere to carries away some heat.

A common adhesive copper foil is about the same thickness as a standard PCB trace, about 35 µm. According to for example this online calculator, a PCB trace of that thickness and 2 mm wide can happily carry 2 A.

A trace of that width and thickness gives the cross-section of 0.07 mm2. A standard copper wire with the same cross-section would have a 0.3 mm diameter and a capacity of about 1.3 A.

The point where the foil connects to the battery contacts is a different issue. You have to make that contact very reliable for the currents that the phone can take in heavy use. Just sticking the foil to the contact and hoping for the best will not cut it. This is why soldering is the best option.

Re: [DIY] Spare Battery for JollaC
 

To be honest, I tried it with copper foil only. It works but not reliable enough from my perspective. Each time you need to remove the battery the potential of destroying the copper foil at the original battery contacts is too high. So every 2-3 times I removed the battery the connection failed.

That's why I switched to cables, which might not be as elegant but it's very reliable.

Re: [DIY] Spare Battery for JollaC
 

How about doing the adaption with a flexi pcb? A quick look suggests it would cost approx $5 each in 20 off.
I can see a few wrinkles, but nothing too difficult to handle.
(I do a lot of pcbs for myself and for work, but I've never done a flexi though I've used them)

Re: [DIY] Spare Battery for JollaC
 

pichlo, MaemoUser, if you say it can cope with the heat, I think I'm going to try without wires...
MaemoUser, I don't know why you need to remove you battery often, but I don't need... Will see...
Thanks
p.s. can we solder only foil to the battery contacts or using any special glue for example: http://m.ebay.com/itm/290695765305?_mwBanner=1 ?

Re: [DIY] Spare Battery for JollaC
 

How stiff is the copper? Can you curl the part that will contact the battery in a similar fashion to the phone's contact pins, and then bend it to the required path. eg:

http://imgur.com/tiiucCrl.png

Re: [DIY] Spare Battery for JollaC
 

It's not stiff, you can bend it as you want...

Re: [DIY] Spare Battery for JollaC
 

I am often in different countries so need to change SIM Cards ;).

Re: [DIY] Spare Battery for JollaC
 

Of course if you are going to use a foil all the way then you need only one solder pojnt, to the original battery contacts. I know conductive glues exist but I di not know how good they are. I would be a bit concerned about how it performs under heavy load. The only way to find out is to try. Please report your results.

I suggest you bend the ends as per mrsellout's drawing. You want to attach the conductive side to the battery terminals, not the sticky side.

Re: [DIY] Spare Battery for JollaC
 

Yes, of course... This is exactly what I intend to do.

Re: [DIY] Spare Battery for JollaC
 

Hmmm, I have another little question. I still afraid a little bit about heating of the foil, maybe it better to put something (2 strips of isolation band) between battery and the foil ? What you think ?

Re: [DIY] Spare Battery for JollaC
 

No need to worry about heating as @pichlo described.

And if it becomes so hot that it might damage the battery without isolation, it will also harm it with the isolation.

Re: [DIY] Spare Battery for JollaC
 

Exactly. Just make sure the strips are at least 2mm wide and you will be fine.

Re: [DIY] Spare Battery for JollaC
 

Thanks guys , will report when I will get new battery :)

Re: [DIY] Spare Battery for JollaC
 

If success, could you please also share components and where to buy? I'm not counting on my JC battery to last forever. ;)

Re: [DIY] Spare Battery for JollaC
 

And please make a few pictures if possible :). So others can reproduce it too.

Re: [DIY] Spare Battery for JollaC
 

Sure, I will take some pictures :)
This is stuff that I purchased. The glue only today, don't know why I didn't think about this brfore :)
The foil already arrived, the battery I hope the next week. Probably I will start without glue (banding of foil + strip of isolation band to hold it in the place) until I will get it...

Re: [DIY] Spare Battery for JollaC
 

You're welcome. I just knew today about this thread. I don't read often here on TMO.

Re: [DIY] Spare Battery for JollaC
 

You are right. This is what I want to do in my next try. One strip of copper foil per side, and a wire for the thermistor (centre contact). I hope to improve high-current transient performance.

Don't worry, foil won't heat. Wrap it in Kapton tape to make sure it won't tear off.

Re: [DIY] Spare Battery for JollaC
 

Is your battery arrived in the meantime? Does it work without glue? If it work, can you post some pictures please? Unfortunately some days ago my battery double the size and I'm looking for solution :mad:

Re: [DIY] Spare Battery for JollaC
 

Unfortunately the battery of my JollaC doubled the size :mad: some days ago, so I'm very interested in an alternative battery :)

Does your battery arrived in the meantime? Does it work without glue? If so, can you post some pictures, please?