G751 Battery upgrade/rebuild

[aeolisio]

First off this is not a guide because the last thing i want is someone to start a fire or damage hardware or themselves because they couldnt follow simple directions.
I have rebuilt and upgraded quite a few laptop batteries over the years and even though none of our g751 batteries have failed i did upgrade 2 of the packs for longer use. You can find walkthroughs online but to make it simple the g751 battery uses 18650 cells at 3.7v and 2933 mah. After some fighting with the plastic case i replaced those cells with Panasonic 3600 mAh batteries. The upgraded total capacity on paper went from the stock battery of 5866mAh to 7200mAh and from 86Wh to 107Wh or a 24% increase. Real world heavy usage has added another 1.25-1.5+ hours for those users. As long as you install the batteries in the same series/parellel config you wont have any problems. Use this as a reference if you need to rebuild or upgrade your own battery and this will certainly void your warranty so attempt at your own risk.

[TheWitcher]

I never did get to thank you for the battery and cooling pad mod. everything still works great and i am getting 7-9 hours of use in high performance mode. i remember you telling me something about balancing the batteries but i lost the info you gave me can you resend it?

[al3xrov3r]

does battery pack have a circuit in it?
what about MCU ( micro controller unit) 's program that contains battery's specificity?

[aeolisio]

al3xrov3r wrote:
does battery pack have a circuit in it?
what about MCU ( micro controller unit) 's program that contains battery's specificity?

Yes it does have its own charging circuit that regulates and balance charges the cells. It uses delta peak voltage to determine charged level so the capacity of the cells doesnt matter for the circuit.

[Computer-Chkn]

aeolisio wrote:
Yes it does have its own charging circuit that regulates and balance charges the cells. It uses delta peak voltage to determine charged level so the capacity of the cells doesnt matter for the circuit.

I got to reading a lot online about the chips in newer laptop batteries having a protection circuit, and if the board receives 0 voltage it gets bricked. Is this not the case with the G751 pack? I really hope so. Because I'd like to go ahead with replacing the cells instead of throwing the pack away and ordering another battery.

[loonie01]

What's the best way to remove the plastic shell that's around the batteries?

Sent from my SM-N920T using Tapatalk

[Alexa1988]

So, after finding a good deal for ssome SONY VTC6 cells I'd like to rebuild my battery. However, a few questions pop up :
1. The MCU, you said it shouldn't pose a problem after changing the cells, correct ? So it isn't an EPROM ?
2. When changing the cells, I can safely disconnect all of them, rework the connections and them reattach them or do they need to be changed 1 by 1 ? Did you solder the batteries or spot weld them ?
3. Is there an easy way of opening the battery pack or just along the joint ?
Thx for your patience man !