Home-brew battery measuring station

[Metallover]

Keep us updated! That's awesome!

[Pdelcast]

Funny how minds work alike. Here is Castle's version:



We are using the new datalogging ESC (Phoenix-ICE 200) to store data from the battery discharge. 9 x 400 watt resistors, 18 x 33,000 uF capacitors and 6 x common mode chokes to keep the battery load as DC-like as possible.

[BrianG]

Originally Posted by Pdelcast

Funny how minds work alike. Here is Castle's version:



We are using the new datalogging ESC (Phoenix-ICE 200) to store data from the battery discharge. 9 x 400 watt resistors, 18 x 33,000 uF capacitors and 6 x common mode chokes to keep the battery load as DC-like as possible.

lol. Instead of 9x400w resistors, I'll be using 60x50w resistors - pretty close power-dissipation-wise. Care to donate one of those Phoenix ICE ESCs? I picked up an Eagletree 150A logger from a member here so that is taken care of, but the ICE would work just as well.

Looks like I'm gonna have to get some caps as well. I assume by the size of yours and the value of yours that they aren't low-ESR? I suppose it's not needed with that amount of capacitance. Maybe a 0.5-1F car-audio cap would work (and probably cheaper). I imagine the hook-up spark is VERY substantial though - or are you using a no-spark resisitor?

My design didn't include chokes - maybe I should look into that as well. I could probably pick up a large toroid (or unwind a spare large transformer I have laying around) and wind one myself. What is the total inductance value of your setup?

What are you using for the throttle control signal; an actual radio, a seperate circuit (like I planned), or using some computer driven control signal? I would LOVE to have a computer-driven control signal so that I can program test runs and have it be consistent for all battery tests. So, if your setup uses a computer-driven setup, PLEASE let me know!

Thanks for your input Patrick. At least I know I'm on the right track; if it's good enough for CC, then it's good enough for me!

[Pdelcast]

Originally Posted by BrianG

lol. Instead of 9x400w resistors, I'll be using 60x50w resistors - pretty close power-dissipation-wise. Care to donate one of those Phoenix ICE ESCs? I picked up an Eagletree 150A logger from a member here so that is taken care of, but the ICE would work just as well.

Looks like I'm gonna have to get some caps as well. I assume by the size of yours and the value of yours that they aren't low-ESR? I suppose it's not needed with that amount of capacitance. Maybe a 0.5-1F car-audio cap would work (and probably cheaper). I imagine the hook-up spark is VERY substantial though - or are you using a no-spark resisitor?

My design didn't include chokes - maybe I should look into that as well. I could probably pick up a large toroid (or unwind a spare large transformer I have laying around) and wind one myself. What is the total inductance value of your setup?

What are you using for the throttle control signal; an actual radio, a seperate circuit (like I planned), or using some computer driven control signal? I would LOVE to have a computer-driven control signal so that I can program test runs and have it be consistent for all battery tests. So, if your setup uses a computer-driven setup, PLEASE let me know!

Thanks for your input Patrick. At least I know I'm on the right track; if it's good enough for CC, then it's good enough for me!

Hi Brian,

The capacitors are low ESR type, Panasonic TS-UP series, 33000uf, 35V. .014 ohms / each at 20khz.

We just threw the chokes in there when it seemed we were still getting a lot of voltage ripple from the switching on the ESC. Turns out that the voltage ripple was from ground bounce -- when we measured it differentially, the ripple went away. But, we left the chokes in anyway. :)


We are using a Castle Link to drive the controller and to log data -- the ICE can only store about 10 minutes of data at full rate. Richard and Jon cobbled up an application to drive the controller and read data while it is running.