precharge and commissioning on non communicating inverters

[karlsolar]

I can't be the only person to need this information, either with a rosie, or in my case an outback inverter, what is the power up procedure for the MN Powerflo 16? 

with the SOK batteries I have used in the past, there is a precharge circuit built in.  you turn on all the breakers, then power up the BMS, which automatically precharges the capacitors. 

do the MN batteries do something similar? I don't just want to throw the breakers and damage something.  the manual seems lacking on things like this and setpoints for those of us wanting to use these on older inverters (or even a rosie)

[ClassicCrazy]

I would think that the midnite battery has precharge in it, but even if it didn't with 16 kw battery bms  rated to have a 210 amp surge  - I doubt you would have any trouble starting up your inverter.

I just looked in the manual and there is a start up procedure on page 18 ( maybe it is revised manual from whatever you have ?)

7.4 POWER ON SEQUENCE
Step1: Check Equipment:
● Ensure that the installation and connections of the battery and related equipment are correct.
● Make sure there are no obstructions around the system and that it is well-ventilated.
● Check that all cables and connections are secure.
Step2: Turn on Battery Breaker:
● Turn the battery pack breaker ON, see if lights on the battery are active.
Step3: Start the Battery Management System (BMS):
● Press and hold the POWER button for 3 seconds.
Step4: Turn on the Inverter:
● Turn on the power switch of the inverter and wait for it to complete its startup

I just saw this on Midnite page for open loop charging specs.
It may have been recently added
Absorb Voltage 56.4V, Absorb Time 5 minutes, Float Voltage 54V
https://www.midnitesolar.com/productPhoto.php?product_ID=768&productCat_ID=61&sortOrder=1

Larry

[karlsolar]

thanks!  The charging info must be new.  I'd looked everywhere. 

as far as powering up the battery, I didn't assume that those instructions applied to non HF inverters.
hopefully i don't fry anything.  maybe I'll precharge just to be safe.

thanks again.

[karlsolar]

Well, there is no pre-charge built in as far as I can tell.  it powered up the radian, but I really didn't like the POP that I heard in the breakers (the inverter breakers, not the battery breakers)  when I flipped them on. I will add some other way of pre-charging.

also, before connecting to the inverter,  when I powered up the master battery I heard a kind of nasty noise that sounded like halfway between a buzz and a sizzle inside the battery.  it appears have to powered up,the run light flashes slowly, but it doesn't display the State of charge bars at all.  the secondary battery flashes slowly and shows 50% SOC bars.

 I powered up a space heater just to check operation and the inverter side works ok, but now I realize I didn't check for current draw from both batteries.  might be able to do that tomorrow.  solar assistant wasn't connecting, but that could have been a separate issue. 

[karlsolar]

Also, the description of the battery charge status light in the manual seems weird.  it's just visual, in that the LED's are indicated as right to left when they are top to bottom on the battery.  it took me like 3 readings to figure out what they were trying to describe. 

on my batteries, the master didn't have the SOC lights on (which the manual says it should) but the secondary battery did. 

and The RUN LED was blinking slowly, even when the breakers were turned off.  the manual says that means they're charging or discharging.  perhaps that's from cells trying to balance themselves after a few months in storage? 

I hope these batteries are as nice as they seem on the outside.  the documentation needs some work.  I'm sure they've got their hands full at midnite, and I'm hoping they make some money on this stuff so they can hire a re-write for the battery manual. 

[mvrck]

I've installed three systems so far. 3 on XW, 2 on Radian, 3 on Radian.
Wiring and boot up.
Pick which battery you want to make the master. Wire the data cable between link out at the master to Link In of the next and Link Out from there to In, etc., daisy chain.

Wire the DC cables, etc.

Turn on all the battery breakers.
Then just press the Power button of the Master battery. It will wake up the other batteries.  Only the Master will show the level gauge. The run led will blink on all.
Then turn on the breaker of the charge controller(s) and inverter(s). That 250A breaker might make a pop when turned on. It's normal, but don't dilly dally when turning on the breakers.

When first charging or discharging, it's a good idea to measure current at each battery just to be sure.

[karlsolar]

I think I'll still put together a pre-charge circuit.  I don't think that arcing can possibly be good for the breakers, or the BMS.

Do you have any suggestions or pitfalls that i should be thinking about with the older equipment and the powerflo batteries?  I'll get the settings right, and all that, but I'm still new to the lithium battery world.  I did my real battery training 20 years ago. 

thanks

[karlsolar]

here is the procedure I got from my supplier, it looks like it was copypasted from someone else, perhaps someone at Midnite?

Thank you for your patience here is the method below:

1- turn on Battery breaker on inverter

2- Turn on PF16 or PF5 breaker(s)

3- Push power button on Master PF

 FWIW.