proper use of NC200 batteries

Discussion about the OutBack Energy Cell Batteries
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mevenable
Forum Member
Posts: 20
Joined: Mon Mar 12, 2018 1:04 pm
My RE system: GS 8048 inverter, FM80 charge controller, 2 strings of 4 NC200 batteries, soon to be 3, 15 panels 270W each (4 kW), Mate3s

proper use of NC200 batteries

Post by mevenable » Mon Mar 12, 2018 1:29 pm

I have 2 strings of four NC200 batteries. I will hopefully soon have 3, they just got out of customs. The system was designed to be able to handle my household needs (which it usually does) and also allow me to pump water from my well for a couple hours in the middle of the day. I have tried doing so, and while the panels do not totally cover the load, there is some deficit, generally 0.5-1 kWH over the pumping time, the batteries still seem to be mostly charged (50.8 V when no load or charging), and recover to pre-pumping levels (flotation at very low input) before the day is over. Is this damaging my batteries in any way? Does it make them have 2 cycles per day, or is it still just one? If I pump, stop, then pump again, will that make 3 cycles in a day?

Sometimes the batteries seem weak at night, compared to when I am not pumping, but other times they do not. Sometimes they go down to relatively low voltages of 46-47.2 V with half the load that it takes other nights. Sometimes they stay above 50V for a kWH or so of use, other times they fall below 50V almost immediately, with the same sort of applied load. I seem to be having a few issues with getting the batteries to charge properly in any case; one day the absorption was almost over, and everything looked normal, it was down to nearly 150 kW - 3 A (1.5% of the 200 Amp Hours and all that), then suddenly in the last 3 minutes of the allotted 2 hours it started Absorbing at 2.2 kW and did so until switching to Flotation, where it consumed 1.1 kW to float them, then gradually decreased to something normal over the next hour or two. Seems like it suddenly discovered the batteries were not fully charged after all. A lot of nights, including the night before that happened, the batteries do not perform well even when they appear to start off fully charged, and this happens whether I have been pumping that day or not, so I really don't know if the pumping has anything to do with it.

Also, one of the battery terminals got blue-green corrosion on it, I cleaned it off, but did not remove the terminal to clean between the parts since I don't have a wrench that wont strip it, but I tested with an ohm meter and there is no resistance between the ring and the top of the bolt, so the contact seems good, and all the batteries seem to charge about equally.

These batteries seem a little quirky anyhow, once I tried a test where I charged them fully and floated for a while, then cut the charge and ran them for 12 hours, consuming a bit over 3 kWH, then cut the load and rested them. The voltage went up to 47.2 V within the first 20 min, then stayed there for about 7 hours, then shot up instantly to 48.8 V. seems like they need burping sometimes?



I am trying to sort out what is going on and what I should do, the present two strings batteries have been in use for about 3.5 months, the gave me pretty good performance at first, then poor in January, then better in February after I upped the panels from 6 to 15, then often poor in March after I got the 8048 inverter and tried pumping (I started with a 4048). I need to get them fully charged and be sure they are in good shape before I install the third string, which has been on order since January. I need to know how to tell if they are good enough to combine, and I need to be sure that whatever I do next does not screw up 3 strings instead of just 2.

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Kurt Lundquist
Alpha Energy Engineering
Posts: 1389
Joined: Tue May 31, 2011 7:23 am
My RE system: VFX3524, Mate3, 200Ah 24V AGM Battery Bank
Location: Arlington, WA

Re: proper use of NC200 batteries

Post by Kurt Lundquist » Tue Mar 13, 2018 11:55 am

The NC batteries like to have a freshening charge every 30-90 days. I think you should give that a try. See manual page 14 for details http://www.outbackpower.com/downloads/d ... manual.pdf

Let us know how it goes.

Thanks!

-Kurt
Kurt Lundquist
Renewable Energy Project Engineer
http://alphaenergy.us/

mevenable
Forum Member
Posts: 20
Joined: Mon Mar 12, 2018 1:04 pm
My RE system: GS 8048 inverter, FM80 charge controller, 2 strings of 4 NC200 batteries, soon to be 3, 15 panels 270W each (4 kW), Mate3s

Re: proper use of NC200 batteries

Post by mevenable » Wed Mar 14, 2018 9:07 am

I might try a freshening charge, but I was not sure that it was needed, since they charge fully every day and are all holding about the same charge

mevenable
Forum Member
Posts: 20
Joined: Mon Mar 12, 2018 1:04 pm
My RE system: GS 8048 inverter, FM80 charge controller, 2 strings of 4 NC200 batteries, soon to be 3, 15 panels 270W each (4 kW), Mate3s

Re: proper use of NC200 batteries

Post by mevenable » Wed Mar 14, 2018 9:46 am

oops - my bad, they are not the NC200, they are 106 NC batteries

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