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Equalizing EnergyCell 200NC batteries

Posted: Sat Jul 30, 2016 9:40 am
by raysun
We have an off-grid system consisting of a FlexPower One (with 3048T, FlexMax 80, etc), 3800 watts of solar panels, and two strings of EnergyCell 200NC batteries (4 x 2, for 8 batteries total.) Each night, we consume about 30% of the battery bank capacity (to 70% SOC), and each day recharge the batteries to 100% SOC. Our total daily consumption is around 6 kWH.

Being lead-acid batteries, is it valid to assume some sort of equalization protocol should be used? If so, how do we best determine when equalization should be applied, and what parameters would best match these batteries?

Re: Equalizing EnergyCell 200NC batteries

Posted: Sat Jul 30, 2016 4:32 pm
by SandyP
AFAIK, equalisations are normally required when individual battery voltages within a battery bank are no longer within specifications and this usually happens after a period of multiple discharges and partial recharging.
Therefore you may require an equalisation after one week or six months of use depending on your discharge/recharge and how the batteries respond to your 'normal' use.

Re: Equalizing EnergyCell 200NC batteries

Posted: Tue Aug 02, 2016 11:14 am
by raysun
Thanks SandyP for the general considerations for equalizing lead acid batteries.

I'm looking for more specific information on equalizing the Outback NC series - VRLA with some sort of carbon 'pixie dust' on the plates that's supposed to improve their PSOC cycling performance.

Guess I'll give Outback a call.

Re: Equalizing EnergyCell 200NC batteries

Posted: Wed Aug 03, 2016 7:44 am
by Kurt Lundquist
If you are recharging to 100% every day an equalize (EQ) cycle shouldn't be necessary. For sealed VRLA type batteries equalize is typically referred to as a "freshening" charge. Freshening is an extended charge at the absorb voltage rate while EQ traditionally means charging at a higher voltage than absorb.

In general you will want to freshen the battery bank when it has spent 2+ weeks at partial state of charge. You can also measure and record the individual battery voltages. When you start to notice the battery voltages drifting from each other you can freshen. For best results try to do this when the batteries are resting. Check each string with a DC current clamp (CT) while the batteries are being charged to see if they are getting a balanced charge or if one bank is taking more power than the other. Over time the carbon pixies will tell you what they need from the data that you gather.

This chart should help you out. I pulled it from the OutBack High Capacity Nano-Carbon manual. Keep in mind these settings are based on a battery temp of 77┬░F. If your batteries are warmer or colder the charge settings should be adjusted. http://www.outbackpower.com/downloads/d ... _nc_2v.pdf
Charge_chart.GIF
Nano_Carbon Charging Targets
-Kurt

Re: Equalizing EnergyCell 200NC batteries

Posted: Wed Aug 03, 2016 9:34 am
by raysun
Thanks Kurt! Just what I was looking for.

BTW - its nice to have the pixies on one's side.