Upgrading the battery? Cheap and easy?

[ayman07]

I posted this on another forum but I thought I could post it here. Sorry if this is the wrong section. I have a Zenpad 4. The 2400mAh battery on it is not that good. I get less than 4 hours with it on wifi. I found 4000mAh batteries on ebay for under $20. These are 7.4v 15C batteries.

7.4V 4000mAh 15C RC Battery AkkU for SH boat car truck - eBay (item 160426803245 end time Aug-21-10 02:49:08 PDT)

I have already taken apart my Zenpad 4 before, I saw how the battery is and how it is connected. My question, is it really that simple? I can easily order one of these batteries, cut the little white connector from the old battery and solder it to the new battery and done! but am I missing something here? the voltages are the same but what about the burst rate? i think the Zenpad 4 has a 5C burst rate. is that a big issue? i dont wanna fry my pad so what precautions do i need take to ensure i have a functioning tablet after? also, what are the dimensions of the current battery? i forgot to measure it and if someone knows, please share. i dont wanna have anything bulging out. I dont mind taking the plunge.

 

[jtbnet]

We think on the same plane Scary... I spent over an hour today researching Li-Poly batteries in a similar footprint so that it would sit inside like the original 2400mAh... The space allocated in the back panel that the existing one fits in is 183mmx63mmx5mm... the current battery is considerably smaller more like 160x45x5... so there is room and maybe a touch thicker than 5mm but less than 8.5mm I've seem in looking... having more power is fine as long as the voltage is the same... these are not high drain compared to the plane and car motors you see a lot of these size for... seems max 8.4v w/5.5v low cutoff so a generic 7.4 as you see them...

 

[ayman07]

We think on the same plane Scary... I spent over an hour today researching Li-Poly batteries in a similar footprint so that it would sit inside like the original 2400mAh... The space allocated in the back panel that the existing one fits in is 183mmx63mmx5mm... the current battery is considerably smaller more like 160x45x5... so there is room and maybe a touch thicker than 5mm but less than 8.5mm I've seem in looking... having more power is fine as long as the voltage is the same... these are not high drain compared to the plane and car motors you see a lot of these size for... seems max 8.4v w/5.5v low cutoff so a generic 7.4 as you see them...

thanks for your input. so the 7volt should be fine then. its basically its as simply as it seems. the only problem would be finding a batter that is less than 8.5mm. the thinnest i have seen them is 12.5mm and that is in the link i provided. I do have an idea tho. if these are two cell batteries, stacked on top of each other, could we just simply remove the tape that is holding them together and just lay them flat next to each other? when i hoped the tablet it seemed like there is enough room for two thin batters, like getting another 2000mAh batter and putting it right next to it. but with this battery, it has two cells but placed NEXT to each other. I am assuming these thicker batteries are also dual cells but placed on TOP of each other. What do you think?

 

[gurgle]

I think we are all on the same plane. The elements I know is the charger amperage and voltage controller can cause a higher potential for non-standard batteries to blow. I had this happen with an aftermarket stuck in a Sony NW-HD1 MP3 unit. The result was the usual swollen battery. But knowing the commodity effect for batteries used, It is worth experimenting. I wish I had another unit which I would not mind if I had a battery "destroy". So I plan in a month to take the plunge anyway. It will be an adventure.

One of the things I am planning to do is place mini-heat sinks (RAM-type) on both the battery and parts of the circuit board. There is a definite warming of the battery as I used it for a continuous period. This won't extend the battery life, but it keeps it cooler as there is not much space for the heat to dissipate otherwise.

 

[ayman07]

someone from another forum found this battery:

2 X 7.4V 4000mAh 20C Li-Po Li-poly RC Battery Pack - eBay (item 190424107055 end time Aug-26-10 10:24:13 PDT)

this one is only 10mm thick but still too much for the room we have. I am worried that damn thing wont close. I mean if the battery is to lay on the motherboard, I dont think it will be a problem in terms of space. We are trying to get it to sit in place of the old battery, but if we place it in there and 2mm is sticking out, its just gonna touch the motherboard. That shouldnt be too much of a problem unless heat is a MAJOR concern. I must say though, with the update to the latest firmware, 818, battery life seemed a lot better.

 

[Kahoolie]

Have you thought about making a 1.5 mm (0.059 in.) shim for the case?