maemo.org - Talk - Battery Tests, Homemade 3000mAh XL Battery & Q&A (POST #1)

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- - Battery Tests, Homemade 3000mAh XL Battery & Q&A (POST #1) - New Layout (https://talk.maemo.org/showthread.php?t=65568)

Re: Battery Tests and Phone Battery Mod

Quote:

Originally Posted by shadowjk (Post 873071)

By "2mm system" I mean the whole combination of powersupply, battery and battery charger, and the relatively peculiar methods and charge algorithms used in all Nokia products with 2mm charge port. Nokia even published a pdf documenting parts of it. I wasn't talking about the connector or your connector as such..

I know, just wanted to show how i use my system.
another good thing with the dedicated 2mm charge plug is that ware & tear is going to be a minimum on the micro-USB, speaking of all those that have experienced loose USB.

Re: Battery Tests and Phone Battery Mod

Quote:

Originally Posted by shadowjk (Post 872721)

I was rather impressed by:

http://www.eastmaze.com/High-Capacit...1394.html?c=63

In a few test runs it's come out as 1310 - 1330 mAh using N900's own battery fuel gauge chip, and assuming RS=21 as determined experimentally by one of the kind sould in #meego.

Impressive that it's as good or better than original Nokia BL-5J, which iirc tested out as 1250-something with the same method.

Internal resistance "feels" like its lower, but that might just be a sign that there's no protection circuit in it...

The bq27200 fuel gauge doesn't use any method close to a "proper" one. It just integrates current discharged, until it reaches 3248mV (and the point at which this happens varies with system load, of course), and then assumes that the battery is at 6%, calibrates charge meter according that. The 0% is assumed to be at 3V.
Under normal operations N900 doesn't reach voltages this low.

My 2400mAh mugen showed up as 2400mAh with the same method when new, and now after some months of abuse it shows up as 2300mAh.

This looks really compelling, like other n900 users battery life has me frustrated too and i am considering on getting a back up battery would you recommend this over the official one? The price certainly is right

I can see you guys are exploring to make a "big tank" battery but isn't just carrying a spare battery easier? Another thing i almost forgot to ask if i'm going the spare battery route, whats a good battery charger for these bl 5js would any on Ebay do?

Re: Battery Tests and Phone Battery Mod

I see you have a Mugen's back cover which came with a bigger capacity battery. How did you get that, or do you also have the Mugen 2400 mAh battery?

Did you just connect two BL-5J batteries parallel on their pins 1 and 2 (+ and -)? How did you manage to do that? Soldered cables tolerable to 1A to the battery contacts, or did you break the cover of the batteries to solder cables inside? More accurate photo of the connection of the two batteries in parallel would be nice.

Re: Battery Tests and Phone Battery Mod

A single big battery has the advantage that you don't lose all open apps and don't need to save and reopen everything when you switch battery.

Re: Battery Tests and Phone Battery Mod

Quote:

Originally Posted by zimon (Post 873735)

I just ordered the cover alone from mugen, the battery's are solder together bare without the circuit board and the circuit board has been relocated outside and just the pins remain in the plastic top from the battery's.
The mugen cover cost 7$ with shipping

will update with more and better pics soon on the 2 post.

Re: Battery Tests and Phone Battery Mod

Quote:

Originally Posted by dr_frost_dk (Post 872435)

And Jopod from DX

It's Japod, described as 1350mAh.

I ordered this: http://www.dealextreme.com/details.dx/sku.32398 4 months ago, and it works well. I even get the impression that it lasts longer than the original Nokia battery; certainly good value for money. I've been using it since I received it, and have not noticed any deterioration.

Japod appears to be one of the better battery brands. I would recommend it.

Re: Battery Tests and Phone Battery Mod

Quote:

Originally Posted by wurtel (Post 874029)

Yes i know it's good, but this thread is to sum all the battery's up for once and for all, so it's still going to be tested.
And if the next ebay battery's are no good than the double battery is going to be made of 2x Japod, i ordered 3, 2 for me and one for my friend

This thread is still a basic buyers guide.

Re: Battery Tests and Phone Battery Mod

Quote:

Originally Posted by dr_frost_dk (Post 874037)

How do you prevent overcharging for each of battery if you stack them together like that?

I also read this article about 6-cell batt on netbook (http://www.engadget.com/2009/02/08/s...arger-touchpa/). Is it possible in the future that mobile phone can use 6 cell batt?

Re: Battery Tests and Phone Battery Mod

Identical Li-Ion batteries of same age will balance themselves automatically when connected in parallell. No overcharging issues, they'll behave alot like a single bigger battery.

As for 6-cell, the ideal for phone is one big single-cell battery. There's no benefit from having multiple cell setup, and dr_frost is only doing it because it's cheaper for him as a consumer/hobbyist to get several common small batteries instead of a custom big battery.

Re: Battery Tests and Phone Battery Mod

But how the phone will detect the capacity of 2000 mah on 2 stack battery?

Pisen bl-5j battery http://www.dealextreme.com/details.dx/sku.39120 i heard also good too