Has anyone taken measurements on how much current the Electron actually draws during different operational modes? I know the spec sheet says the max peak is 800 - 1800 mA with cellular, but has anyone measured current draws close to this? I haven’t measured anything in excess of 300mA even with frequent data transmissions over 3G and am wondering if/under what conditions it would actually draw the peak current stated.
How did you measure this? If I'm not mistaken, your average multimeter can't register these peaks, though they're definitely there.
Initially connecting to the tower is apparently a power hog.
I used a Fluke 87 which is rated up to 10A in series with a 5v regulated output rated up to 6A and the Electron’s Vin & GND pins. I definitely saw a spike when initially connecting to the tower, but it was on the order of 200-300mA compared to a nominal operating current of ~ 45mA (or ~180mA when publishing), but still much lower than the stated maximums.
Are you using a 2G Electron or 3G?
Only the 2G get that high and only for very brief moments.
I’m not sure your Fluke will read that fast.
1 Like
Have you tried moving the Electron out to be just within cell service or alternatively install an RF attenuator inline with the antenna to see peak power usage?
Ah I'm using a 3G. Any idea how much lower the peak would be? I'm mostly concerned if the spikes will occur regularly during publish events or if it's only when initially connecting to the tower.
Yes to the former. I didn't see much of a difference though
Considerably. I can only talk from hear-say, but think to recall that it was around the lower bound of 800mA, but I guess @BDub or @mohit could provide better figures.
I would try adding attenuation in 10dB steps until the Electron does not connect, and then go back 10dB (or 5dB if you have it). You want to be just on the edge of the radio coverage so that the cellular modem has to boost transmit power to the maximum.
Fluke 87 is a nice multimeter, but you really need a scope and a current shunt to see transient power problems.
4 Likes
Like @bko suggested, it’s not easy to see transients using a multimeter alone. You’ll definitely need a scope for that. The power consumption will also depend on the class of transmission and other factors. While I don’t have these measurements readily available, the u-blox datasheet does a great job of explaining this.
2 Likes