monkeytennis
New Member
Hello.
I was just wondering whether anyone had tried using a DS2438 1-Wire Smart Battery Monitor chip with a 12V lead acid battery. The chip includes an 8 bit internal current accumulator, a 16-bit charging current accumulator and a 16-bit discharing current accumulator which can be used to calculate the remaining capacity inside a battery in Ampere-Hours. This current accumulator, however, is designed for batteries which have only a maximum of 2.5Ah capacity so I was wondering whether it was possible to maybe cheat the system into thinking it was a smaller capacitance battery. I already know how to convert the voltage to a measurable range (as the DS2438 requires 1.5-10v input) but am not sure about the current.
One idea I was toying with was to perhaps have a long variable for charge inside the master (in this case a PIC18F252 microcontroller) and every, say, 10 minutes read the values of the charging currents/discharging currents and add/subtract from the internal variable accordingly, thus hopefully enabling me to establish the remaining capacity.
The system I have uses a PIC18F252 microcontroller (programmed in CCS PIC C) hosting a Dallas 1-Wire bus to which a DS2438 battery monitor chip is connected. This chip is monitoring the status of a 12V, 84Ah Lead Acid battery from which the system (amongst other things) is powered.
Any thoughts/ideas would be appreciated.
Cheers,
Simon
I was just wondering whether anyone had tried using a DS2438 1-Wire Smart Battery Monitor chip with a 12V lead acid battery. The chip includes an 8 bit internal current accumulator, a 16-bit charging current accumulator and a 16-bit discharing current accumulator which can be used to calculate the remaining capacity inside a battery in Ampere-Hours. This current accumulator, however, is designed for batteries which have only a maximum of 2.5Ah capacity so I was wondering whether it was possible to maybe cheat the system into thinking it was a smaller capacitance battery. I already know how to convert the voltage to a measurable range (as the DS2438 requires 1.5-10v input) but am not sure about the current.
One idea I was toying with was to perhaps have a long variable for charge inside the master (in this case a PIC18F252 microcontroller) and every, say, 10 minutes read the values of the charging currents/discharging currents and add/subtract from the internal variable accordingly, thus hopefully enabling me to establish the remaining capacity.
The system I have uses a PIC18F252 microcontroller (programmed in CCS PIC C) hosting a Dallas 1-Wire bus to which a DS2438 battery monitor chip is connected. This chip is monitoring the status of a 12V, 84Ah Lead Acid battery from which the system (amongst other things) is powered.
Any thoughts/ideas would be appreciated.
Cheers,
Simon