methods
1 GW
Ok... I bounced around a few ideas and had to pivot.
For lack of time... and positive past experience... I will go with the LTC6811
Application: low complexity BMS suitable for 4S and 8S boating and lawn mower applications. Must scale to 28S for Zero battery module.
History:
TLC6811 is a drop in for the 6804
Read all about it here in the datasheet
The 6804 is an evolution from the 03 and 02
I developed around the 02 (4 BMS versions) in the addressable flavor.
Major pain was in parts count:
* Zener on every channel
* RC filter on every channel
* Mosfet and load resistor on every channel
* Addressing was a bit sloppy
For this run requirements have changed.
* We will be running no external zener protection
* We will forgo RC filters
* We will limit balance to 60mA thereby eliminating the mosfets
* We will go with the daisy chain flavor this time
So what will that buy us?
48 less parts on the board (for 1 chip) so 4 parts less per channel and almost 150 less parts for a design big enough for a Zero battery.
That makes a difference... let my tweezer hand tell you alllll about it.
I just started... so here is my implementation so far:
Balance Math:
Internal fet has a 25ohm inline
Max is 60mA, math tells me 45ohms is what we need outside
That's 162mW outside and 90mW inside
90mW * 12 = ~1W (So can not turn them all on... but manageable for a small tssop)
Onward ->
-methods
For lack of time... and positive past experience... I will go with the LTC6811
Application: low complexity BMS suitable for 4S and 8S boating and lawn mower applications. Must scale to 28S for Zero battery module.
History:
TLC6811 is a drop in for the 6804
Read all about it here in the datasheet
The 6804 is an evolution from the 03 and 02
I developed around the 02 (4 BMS versions) in the addressable flavor.
Major pain was in parts count:
* Zener on every channel
* RC filter on every channel
* Mosfet and load resistor on every channel
* Addressing was a bit sloppy
For this run requirements have changed.
* We will be running no external zener protection
* We will forgo RC filters
* We will limit balance to 60mA thereby eliminating the mosfets
* We will go with the daisy chain flavor this time
So what will that buy us?
48 less parts on the board (for 1 chip) so 4 parts less per channel and almost 150 less parts for a design big enough for a Zero battery.
That makes a difference... let my tweezer hand tell you alllll about it.
I just started... so here is my implementation so far:
Balance Math:
Internal fet has a 25ohm inline
Max is 60mA, math tells me 45ohms is what we need outside
That's 162mW outside and 90mW inside
90mW * 12 = ~1W (So can not turn them all on... but manageable for a small tssop)
Onward ->
-methods