[blastexx]

My eken m001 now has a 3600 mAh battery and it still has it's orginal housing !I placed a second 7.4V 1800 mAh battery in parallel with the internal battery inside the eken m001 and it works ! The batteries i used are identical to eachother and i first fully charged them both seperately.I am now testing the battery performance, the only downside is that it is a very very tight fit (actually it bends the case somewhat

). The battery is placed under the motherboard.Here are some pics:

 

[blastexx]

I got the battery from ebay:Replacement Battery For EKEN MID M001 M002 Tablet PC - eBay (item 200488443962 end time Jul-26-10 21:18:50 PDT)

 

[blastexx]

OK, i have measured the total battery time with wifi off and it is a whopping 6 to 6,5 hours!The next time i will measure it with the wifi on, but i think it will be about 4 to 5 hours.Charging the battery right now

 

[blastexx]

The battery fully charged in 3 hours. It's safe to say that the battery mod works

 

[blastexx]

both of the batteries have a balancing board, so my guess is that this will protect the batteries from overcharge/discharge.I have seen multiple website about battery mods for laptops and they have even put 3 battery packs together in parallel.If my eken starts to fizzle i will let you know But by the looks of it, it is working fine.I don't feel extra heat or hear strange sounds coming from the batteries.I think the most important thing is to first fully charge them separately before you put them together.

 

[blastexx]

There are no solder leads under the motherboard, i checked that.I charged the batteries with an open case and the batteries did not heat up extremely, but your right about the cooling. If i could just find another spot for the extra battery, but there is just no room elsewhere in the Eken Besides, all mods are increased risks, that's why modders do it. You could fry your machine or you can make it better

 

[blastexx]

I think it is pretty safe.The battery pack consists of 2x 3.7v cells in series connected to a balancing board.The charge voltage is 9v, this goes to both batteries.So the batteries cannot overcharge because they both have their own balancing boards present.If one battery fails (due to overcharging) it will switch off and the other one will take over.The guy in the article charged the lipo battery WITHOUT a balancing board, this is indeed not wise!

 

[blastexx]

Battery pack cells are balanced when all the cells in the battery pack meet two conditions:If all cells have the same capacity, then they are balanced when they have the same relative state of charge (SOC.) In this case, the open circuit voltage (OCV) is a good measure of the SOC. If, in an out-of-balance pack, all cells can be differentially charged to full capacity (balanced), then they will subsequently cycle normally without any additional adjustments. If the cells have different capacities, they are also considered balanced when the SOC is the same. But, since SOC is a relative measure, the absolute amount of capacity for each cell is different. To keep the cells with different capacities at the same SOC, cell balancing must provide differential amounts of current to cells in the series string during both charge and discharge on every cycle.

 

[blastexx]

Update:My eken is going strong, no overheating and no fire of any kind am i the only one who tried a parallel battery mod?

 

[blastexx]

source: Wikipedia.Also of interest re. Lipo protection, both circuitry and physical: over discharge, cell swelling, cell puncture, overheating. Also re the Eken's charger: output capacity relative to charge rate and power-on board draw.

Complex indeed

 

[blastexx]

@enotar: where did you buy the two 3500 mAh batteries? i would like to have those too !

 

[blastexx]

Update: Still no problems with the battery

 

[blastexx]

Update:Still no problems...

 

[blastexx]

Still OK I will measure the battery uptime again when i have the time.

 

[blastexx]

@metal03326: The battery i have bought is indeed much smaller than the stock one, see the ebay link at the first page of this [email protected]: My eken charges with the original charger, so the blue light will come on when it is charging and will go off when it is fully charged.

 

[blastexx]

i think you have answered your own question, the problem is that i did not find any 7.4V battery with a balance board and more than 1800 mAh that fits inside of the eken M001....

 

[blastexx]

I will place some more pictures and maybe a video if i crack open my eken again