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        Build Log PLD-MCC1: mAh fuel gauge for up to 30V 30A with LCD

#1 PLD Nov 03, 2011 10:25 AM

PLD-MCC1: mAh fuel gauge for up to 30V 30A with LCD
The PLD-MCC1 is an extension from the PLD-SCC1 with one major difference, it's designed to handle much higher voltages and current levels.

Moving to the higher voltage was the biggest hurdle, as the mAh counter chip is only rated for 8.5V maximum.

The prototype PCBs were sent off for production today... probably 3 weeks away at least. Hoping that everything gets back before the Christmas slowdown starts to kick in.


#2 PLD Nov 10, 2011 09:55 PM

PCBs for the MCC1 have been shipped out - will be a couple of weeks before they arrive (standard post).

#3 ggcrandall1 Nov 13, 2011 06:29 AM

Is there any chance you can build a 60 to 75 amp unit? I use a max 4S battery but have a couple of planes pulling 50 to 60 amps. I'm certain I'm not alone in this power range.

It would sure be nice to be able to verify what my charger thinks was taken out of a battery. I'm very impressed with what I've seen of your product line.


#4 PLD Nov 13, 2011 06:35 AM


If the MCC1 boards work out how I want them to, then it's a moderately simple process to move to 50~100A. The hardest bit then becomes handling the cabling on the boards (what gauge are you using? 4AWG ?). The minimum resolution of the unit also does of course increase as well, but it's still fairly fine (for 100A it would be every ~10mAh consumed).

#5 ggcrandall1 Nov 13, 2011 06:42 AM

The biggest gage wire I use is 10. But that is an exception, mostly it's 12 or 14. For what it's worth I am a Deans plug user.


#6 PLD Nov 13, 2011 06:57 AM

10AWG is certainly still a hefty chunk of wire. The problem arises with trying to bond that to the PCB without risking the copper being pulled off. What I think I might do is actually move the whole sensor element into a separate module, much like they do with things like the hyperion emeter and such. Then the only thing coming to the LCD module is some light 24AWG leads (4 required).

#7 PLD Nov 22, 2011 11:59 PM

1 Attachment(s)
Circuit boards just arrived for the MCC1. Now I have to wait a few days or a week before I have the the extra parts required to test it out.

#8 PLD Nov 25, 2011 04:06 AM

1 Attachment(s)
The crucial part arrived today - so I was able to start development a little sooner than anticipated.

I was surprised I must admit that my "method" worked, so now I can embark on the process of actually making this unit do the job.

Tonight I'll need to make up a 0.002 ohm shunt which will give me up to 25A flow normal and 50A if needed for peaks.

Next step... making a high voltage high current battery pack rig to properly test it!

#9 PLD Nov 29, 2011 11:43 PM

The proper current-sense shunts arrived today - fits very nicely on the board. I now have to wait for the right sized wire to arrive. Heaviest I have at the moment is 16AWG which is okay for most situations but might not be considered heavy enough for 40A peaks.

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