Thread: [insert name of project] worklog

Originally Posted by jmullan99

Did you put an ammeter inline? Any idea on what the idle current is?

Don't have any idea at the moment. I've got a hall sensor ammeter thingy but I need to find the cable to hook it into the fusion brain. I also want to write an app that reads the voltage and amps and logs it so I don't have to hook up the voltmeter.

Right now after ~23hrs I'm at 12.37. Also, the initial voltage may be 12.5X since I didn't exactly read it on the right resolution (didn't know my voltmeter could read hundredths of a volt).

It's also noteworthy that I'm testing on the kenitik hc800 which is a little over half the capacity as a normal car battery. This experiment gives us a safe guess at how long we can run it without killing the battery as actual results should be better especially when we start optimizing the software.

That kind of battery draw is pretty impressive Trip, with figures like that, you could easily leave this kind of unit powered permanently.

Although, having said that, I would still have an easily accessible external plug to allow me to quickly plug in a battery maintainer if I was away for a few days....

I checked it this morning and I'm down below 11.4 volts. I think this is a safe place to call it since it's only a matter of time before the power supply hard-kills it.

Total runtime was 5.47 days. Here's a plot of the voltages.



I expected around 4 days so the extra day and a half was a pleasant surprise. Now it's time to start optimizing and see if we can increase that runtime some more.

I'd like to point out that your starting voltage is a good "average" place to start. A good condition fully charged car battery should read 13.25 - 13.5 and therefore some people could expect it to do even better. Couple that with any optimizations and we are talking excellence!

Cheers

Very impressed with the results. Out of curiosity, what programs/services were running?

subscribed, very interested in this

Originally Posted by matt11601

Very impressed with the results. Out of curiosity, what programs/services were running?

I had the system hanging out in the ubuntu gnome login screen. In reality, there should be virtually no processing that goes on while the car is off. proximity will be the only thing waking up periodically to check for bluetooth devices other than that, it should be pretty quiet.

Looks like the usage is roughly linear, which makes it nice and predictable!

Hello
Will it be the same current drop in the car ? There is other devices which are in standby mode, draining a little current too