The ISL88739 & ISL88739AHRZ are a highly versatile combo battery charger
configurable for operating as either a Hybrid Power Boost (HPB)
charger or a Narrow VDC (NVDC) charger, supporting 2-, 3-, or
4-cell batteries. Both configurations allow the battery to work with
the adapter together to supply the system load when it exceeds
the adapter capability, referred to as system Turbo mode. HPB
charger configuration reverse-boosts battery energy to the system
bus to help the adapter provide the system power in Turbo mode.
NVDC charger configuration...

ISL6257HRZ ISL6257HRZ-T Laptop Battery Charger Datasheet

Highly Integrated Narrow VDC Battery Charger for Notebook Computers

The ISL6257HRZ ISL6257HRZ-T is a highly integrated battery charger controller
for Li-Ion/Li-Ion polymer batteries. ISL6257 is designed for
Narrow VDC applications where the system power source is
either the battery pack or the regulated output of the charger.
This makes the max voltage to the system equal to the max
battery voltage instead of the max adapter voltage. Operating
at lower system voltage can improve...

I have an RC radio handset(Taranis QX7) which doesn't have internal battery charger which means I had to remove the battery every time I needed to charge it.
So to improve it, I added a 15W USB-C charger board(link) inside and soldered it to the same connector on the PCB where the battery plugs into, great, now I can simply charge it with a USB-C cable.

but the problem I found is that after the radio sat for two weeks without being used the 2S 18650 battery that I'm using was at 4.2V!
So the battery is backfeeding the charger and being drained.

How can I prevent...

Hello guys, i need help with this problem, I have a NM-D041 mobo, it came with low impedance in 3v linear regulator rail, the cause was a damaged EC controller ITE8227e-192. I ordered a new one and replaced it. This laptop have a different chip for keyboard management and it8227e pins for programming ITE chips are not accesible through keyboard interface, I flashed it using i2c interface pins with vertyanov programmer because laptop was dead and SPI flash didn't have power (only 3v EC) so it couldn't access firmware stored in SPI memory. I read SPI and extracted it8227 firmware from original BIOS...

My question pertains to understanding the control circuity inside a Dell PT434 type battery used in Dell E6400, E6410 and other Dell notebooks?

Does anyone have a circuit diagram for the inside of a Dell PT434 battery and/or a description of how the control lines work to control this battery?

My reason for asking is I have a battery which I cannot get to charge beyond 1% in a Dell E6410 or E6400.
The LED bar graph charge indicator on the battery shows one LED lighted when the info button is pressed.
I have tried multiple different Dell power adapters. My Dell...