Phase On testing of my MPP PIP-2424LV-MSD

[Jim Burrow]

I've begun to test my MPP controller 2424LV.

Quick Note - Although the MPP manual and the MPP tech support say I don't need to but a resister between the controller battery input terminal and the negative side (I don't think it makes a difference which side) to protect a BMS capacitor before connecting the battery directly, I didn't do that first and I did get a spark using my lead-acid 24-volt battery (2 12vdc in series). After that, I used a 50-ohm resistor and that stopped the sparking. So to be safe, I recommend using the resistor even though you hear differently.

Issue - When connecting an 860 watt, 8 amp current draw, my battery current pegged my 60 amp meter. Don't know why. When I had a 100 light bulb connected as a load, the battery only discharged at an 8 amp rate.

Testing
Phase 1 - wiring up my controller/inverter for testing using 120vac grid power and 2 12v batteries in series for 24v. See photo!
Phase 2 - Testing the setup with the controller/inverter (2424LV)
Phase 3 - testing battery current using an 860-watt portable floor heater in my hanger.

Phase 2 testing results - I'm happy with the results

July 29, 2020 – Phase ll testing (phase l was wiring up to the controller/inverter)

Testing out my MPP Controller/Inverter (PIP-2424LV-MSD) using 120vac from the Grid/Utility line and 2 12-volt batteries connected in series. The batteries are just for testing and I found them in a throwaway recycle bin out at my local airport where I have a hanger.

For a load out of the 2424LV output line, I used a 100-watt incandescent light bulb and a remote 120 volt to turn the Grid power on an off.

• I tested what happens when only the 120vac grid line-in is connected to the controller.
• I tested what happens when just the battery is connected
• I tested what happens when both Grid in and battery are connected
• The Controller worked as it was supposed to.
• Both the Grid and the batteries independently powered the 100-Watt bulb load.

LCD display
When the Grid power was on, the controller LCD display was showing that the batteries were charging as well as powering the 100-watt load.

Problem - with 860-load
*** With respect to the battery discharge stats, the LCD display was showing the batteries at 24.5 volts and the current discharge at 8 amps. I also connect a 60-amp current meter in the positive lead of the battery and it too was showing somewhere between 3 and 10 amps. I would guess closer to the 8-amp point.

 

[snoobler]

I'd make sure both your 12V are in a decent state of health/charge.

I know old school stuff is often better, but I'd look at a DC clamp ammeter you can just clamp around a wire. A reading of between 3 and 10A just sounds unreliable.

 

[Jim Burrow]

Yes, the clamp ammeter is on my buckle list for next month's budget. I'm not planning on keeping the manual current meter in the system. I've already ordered and should have by next week a 100 Amp current protector for the batteries. I probably will not be able to get the 24V LiFePO4 Powerwall pack until the end of August and the Arrays in October.