Slightly different new battery for my used Kindle DX-G

[Dr. Drib]

What would happen if I used a 3.7v/1530 mAh Li-ion battery for my Kindle DX-G, but one not made specifically for that Kindle?

I won't be going back the U.S. until Christmas, and my current battery only lasts 3-4 days or so. [Apparently, batteries of this nature cannot be shipped to Peru - to individuuals, I mean.]

I'm sure I won't have any trouble finding one with the right v/mAh requirement, which is listed above. However, what this means is that it might not have the two places on the side for it to screw onto the Kindle.

Any thoughts on this from anyone?



Don

[SampleAndy]

It's been a long time since electronics classes, but I feel safe in saying that as long as the voltage is reasonably close, you'd be fine. When I opened up my K1, the voltage marked for input was 5 volts DC, but the battery was 3.7. I'm pretty sure that a higher (or lower) mAh rating would just affect the length of time before you'd need to recharge. It would also change the length of time for the battery to recharge. The biggest problem I could see would be that you might have to take a page from the K4 design and glue the battery in place.

(I almost forgot the part about not being an expert on the subject and that I refuse to accept any legal responsibility for damage resulting from blah blah blah.)

[Dr. Drib]

Thanks, SampleAndy.

I should have mentioned that the specifications in my post are correct. Rather, it would be the absence of those connectors that screws the battery in place.

I don't think there will be any problem in finding a battery with those specifications. I could be wrong, however.

I'll keep everyone posted on this issue.





Don

[SampleAndy]

Don,
I didn't mean that your specifications were incorrect, just that electronic devices are "designed" with more flexibility that you might expect. I did a quick search for a comparison chart, but the closest I found was this statement from wikipedia, "...In zinc-carbon or alkaline types they produce around 1.5 volts per cell when fresh. Other types produce other voltages per cell (as low as 1.2 volts for rechargeable nickel-cadmium, up to around 3 volts for lithium/manganese dioxide)...."

If you can find something with the same specifications... or close, you should be fine.

(repeat disclaimer) ;-)

[Dr. Drib]

I still haven't checked Radio Shack, but I'll do that later today or tomorrow.

I went to a mercado this morning - a place called 'Computer Palace' - and tried to find one.

The only thing close was 3.7v/1100 mAh. It's apparently a cell phone battery.

Of course, there were no holes for screws.

I'm not certain how this would work, or if would be adequate.





Don

[montalex]

If the battery fits, and the contacts are in the same location, I'd bet you could use double-stick tape to hold the battery down, and stick a thin piece of rubber on top of the battery so that the Kindle case back would keep it from moving.

[Dr. Drib]

Well, it looks like finding a battery with 3.7v and 5300 mAh is not possible in this country.

There appear to be a number of batteries with 3.7, but the mAh is somewhat lower, since they appear to be geared for cell phones.

On a happier note, it looks like the battery is not depleting quite as rapidly as I had thought. I might be able to get 4-5 days out of it - maybe a day or two more if no indexing occurs - before I feel it needs a new charge.

I should be able to last until I visit the U.S. for Christmas.




Don

[psycholoner]

I officially DO NOT recommend this. The problem isn't about the material the battery uses. All lithium ion batteries are basically the same (with the exception of whether they max out at 4.2v or 4.1v). The main problem is the protection circuit, level detection, and any other circuitry that's been interfaced to the kindle. These circuits are usually part of the block you see as a battery. The block is actually a case that holds the battery with the circuit which then has pins or pads that stick out to connect to whatever it needs. If you know what you are doing, it might be possible to open up a different battery and attach the old circuit to it to run on the kindle, but its pretty risky due to the fact that bare batteries are serious hazards that can cause fire and explode if mishandled.

Putting in a battery that isn't meant for the kindle may actually cause problems. I doubt it will work (and if it does, you're lucky), but you are also running the risk of frying the kindle if something goes wrong.

If you know what you're doing, go ahead, but its really not worth the risk if you don't. Wait it out until you get a chance to pick up a new battery.

[hawhill]

What psycholoner said - and a short addition: Some batteries even contain some logic parts that expect to communicate with the host - and this typically means that the host expects the battery to communicate, too. I'm not sure whether this is the case for the KDX - a sure hint of such parts is a third cable to the battery (like you will find on probably all mobile phone batteries).

[twobob]

The battery in the kindle 3 does indeed have SDA SCL pins

I just ripped open a kindle 2 to check and it also has 4 pins marked (+) (-) (D) (C)

So it's a safe bet that the DX is also a smart battery
http://sbworkshop.com/sbdat110.pdf

Honestly I can't give you a complete and total answer but I think err on the side of caution is in order.

Hope that helps.

(I'll try to take some pics)
EDIT: Hmm only have a phone camera. but as you can see 4 pins on both.

[Dr. Drib]

Originally Posted by psycholoner

I officially DO NOT recommend this. The problem isn't about the material the battery uses. All lithium ion batteries are basically the same (with the exception of whether they max out at 4.2v or 4.1v). The main problem is the protection circuit, level detection, and any other circuitry that's been interfaced to the kindle. These circuits are usually part of the block you see as a battery. The block is actually a case that holds the battery with the circuit which then has pins or pads that stick out to connect to whatever it needs. If you know what you are doing, it might be possible to open up a different battery and attach the old circuit to it to run on the kindle, but its pretty risky due to the fact that bare batteries are serious hazards that can cause fire and explode if mishandled.

Putting in a battery that isn't meant for the kindle may actually cause problems. I doubt it will work (and if it does, you're lucky), but you are also running the risk of frying the kindle if something goes wrong.

If you know what you're doing, go ahead, but its really not worth the risk if you don't. Wait it out until you get a chance to pick up a new battery.

Thanks for the advice, which I am taking to heart.

Yes, I'll just let this one go, since I'll be in the U.S. anyway in December to spend Christmas with my family. I'll pick one up then, which is the safest thing to do.


Don

[Katsunami]

As said in the first reply: if the voltage is close AND the connections on the battery are correct, nothing bad will happen. It is how the third party batteries are made; just by approximately copying the original.

Actually, sometimes batteries are interchangeable. For example, the Fuji X100 digital camera uses the exact same battery as my Ricoh GXR-M. You can't really find any third party batteries for the Ricoh, as it is not a well known camera, but you can find plenty for the Fuji.

More mAh will make your battery last longer though. It's just how much power it can store.

You probably wouldn't need the screws; you could basically tape the battery in place. It's done that way in quite some mobile phones.

What psycholoner said is also true though: you'd need to get a battery that has a good protection circuit to keep it from overcharging, etc. As far as I can see, there are many third party Kindle batteries around, but I don't know if they can be shipped to your location.

[Sideromelane]

Everything (and i do mean EVERYTHING) that uses rechargeable batteries these days runs on 3.7v, from Nokias from 10 years ago, up to the latest tablet computer - pull one apart and you will find two, or three, lith-ion 3.7v batteries daisy-chained together. My bike lights run on 3.7v cells, which are £1 each, or, I can dismantle an old laptop battery and get six of them.
I had a PDA that ran on an old Nokia battery for over a year after the original died, it recharged just fine from the PDA's original charger. (Eventually I dropped it, the sceen wasn't worth replacing.)

Most devices state a 5v input - this is to allow the device to charge more quickly, and to let you use it WHILE it's charging. The mAh number is just an indication of the lifespan of the output - the higher the number the longer the battery lasts before it goes flat.

The PROBLEM you will run into is low-quality construction of aftermarket batteries. Cheap Chinese (this is a little stereotypical, but also has too broad a stroke of truth to ignore), imports often overheat or explode, because of leakage across the layers of the polymer sandwich that make up the battery. Any battery that costs less than the shipping fee is probably an aftermarket 'fake', which is either counterfeit, or was rejected from the real manufacturers production line.

If you REALLY want to keep your kindle alive until you can get ahold of a decent quality replacement, grab an old laptop, make sure the battery is flat, strip the battery apart and pull the cells out. I've done this with a few, flat is safer!

http://www.ebay.co.uk/itm/Li-ion-Bat...item33846b4a1a will charge those puppies quite safely. I use one myself all the time.

http://www.ebay.co.uk/itm/Double-USB...item56587bc774 will then take the charged up cells, and supply 5v DC to charge your kindle up! - This thing will also charge by USB, not sure how quickly it will do it compared to a charger driven by the mains.

I use these things for EVERYTHING, bike lights, phone/kindle/camera travel charger etc.

[Dr. Drib]

Charging my Kindle is no problem: I just plug it into a wall outlet with my official Kindle charger.

Attaching a dangling USB portable charger is not an option, as the battery in the Kindle l lasts (I now realize) about 5 days.

There is more than enough time to simply purchase a new battery when I go back to the U.S. for Christmas.



Don

[Katsunami]

If you have the opportunity to recharge the Kindle overnight at least once every five days (I assume you're not going camping or anything), then I'd not even worry about getting a battery *now*, if you know you'll be able to easily get a good one later on.