hwy17's Orion battery build

[hwy17]

The Mean Well emits a particular sort of ringing 60hz hum. I'm not sure yet if I find it unpleasant but I think I can hear it from the kitchen.

It's just slightly warm to the touch so far.

 

[hwy17]

Oh, PHEW. The 60hz ring is either coming from the 185W or an interaction between it and the 2300W. The 2300W is SILENT on it's own.

 

[hwy17]

Changed balancing to start at 3.42 and don't balance any cells below 3.42.

 

[hwy17]

The Orion is adjusting my charge current limit based on cell resistance. This is an area of battery theory that I am unfamiliar with, but it seems like a more intelligent figure than SOC based current limit curves.

 

[hwy17]

Exciting, an SOC drift event and resulting deactivating of the charger based on the SOC triggers.

 

[hwy17]

Odd though, I don't have an 80% drift point configured, so I don't know exactly what logic did that.

 

[hwy17]

I have turned the corner from CC to CV without any problems so far.

 

[hwy17]

Oh but I see the most precarious part was still to come after that. Oh well, 3.55v never hurt anyone right?

My budget model Fluke 101 says 55.22v at the charger terminals, but my BMS says 55.3v. Who do I believe here? The BMS, I think.

 

[42OhmsPA]

You'll be fine at 3.55V as long as you don't leave them to long.
I'd hold them at 55.2V for a while (overnight) to let them balance out a bit.
Do you have another meter to verify / check?

 

[hwy17]

3.555v now I'm cutting the charger off and they will continue balancing as long as they stay over 3.42. Time for a better meter I think.

 

[hwy17]

Restarted at 55v and the highest cell voltage is now headed in the right direction.

 

[hwy17]

Yay when I was watching highest and lowest cell last night, they didn't seem to be moving at all for a few hours, but they did overnight.

I believe I have found the answer to one of my questions above. At least in the case of the Orion, it being described as having 200mA balancing current, it looks like 200mA of charging current is what holds steady state balancing.


Edit: <100mV delta milestone passed. BMS is configured to balance until <10mV. If I were to do this again, the excursion to 3.55 was unnecessary. I would start at more like 54v, get it steady, and then move to 55v. It didn't really click for me until I'm actually doing this now that you could have like charge to 3.375 avg and balance at 3.45 and your high cells will still poke through the balancing threshold.

 

[hwy17]

 

[hwy17]

This is the load and charge controller wiring, more or less done. Behind this battery controls box is a Lifepower4, and it's wired directly to the inverter terminals doubled up on the main battery lugs. My idea is that the Lifepower4 provides a little bit of redundancy here, particularly to keep the load online while software maintenance is being performed on the main battery. It violates the seperate charge and load design topology a bit, but I figure at the location it's in, as long as both batteries are online, the Lifepower4 should always primarily act as a load unless the batteries have been disconnected. There is also a disconnect switch so that the Lifepower4 can be maintained and individually charged if necessary.

I restarted the charge last night at 55v charging and balancing at 3.44. Glad to see the high cells are in line now. I will drop the balancing to 3.437 and see if that is enough pressure to drag the low cells all the way.

 

[hwy17]

Oh, wait, that's already a .010 delta! Balancing is nearly done. The Orion only allows settings down to .005. I am setting it to .007 now.

 

[hwy17]

Ok, the house is up and running on double conversion now. An SOC trigger will turn the charger on at 50% and off at 80%.

The plan for now is periodic balancing will be manually initiated with the charger on override of the SOC trigger. This spring, hopefully solar will get online and then solar charging should be regularly providing full charges.

 

[hwy17]

Should I be concerned with loaded resistance discrepancies? I'm not going to be, unless I find out there's a reason to.

 

[sunshine_eggo]

I would double check that all connections are torqued to the same values.

Is this also potentially the sense harness resistance? If it's the sense harness resistance, I wouldn't worry that much.

 

[hwy17]

I would double check that all connections are torqued to the same values.

Is this also potentially the sense harness resistance? If it's the sense harness resistance, I wouldn't worry that much.

I hand checked them for warmth and they're all cold. I torqued them by feel and I'm hesitant to mess with them unless there's a problem. Could be sense harness but resistances are all .50 at rest.

 

[sunshine_eggo]

IMHO, get a torque wrench. You have too much invested to leave out this comparatively inexpensive tool.