Outback NC106 battery issues - wont charge

mevenable

I installed a solar energy system in my farm last December.  I have three banks on four 12 V NC016 batteries, two installed originally and one added in March.  One of  the batteries in original strings started corroding at the terminal in march, and by early April Outback had approved replacement under warranty.  From there, nothing has happened.  I have been unable to get a status update; every time I talk with tech support, I am told that they will tell someone to get back with me, but I never hear back. Their battery expert usually will not answer his phone, but the one time he did, he promised to get back and never did.  The local installer here in Nicaragua promised to look into it and get back, but never did.  Finally, I learned that they had only one such battery left in stock here. and I went ahead and bought it, since almost three months have gone by and there is still no answer, and my original batteries are now 7 months old.  New batteries should be added in the first 6 months if possible

So, I bought the one and only battery, which was manufactured in Feb 2018, same as the third bank I installed in March.  It had 12.4 V on it when I received it, so it looked fine.  I did the proper prep work the same as for the new bank in March, floating the other batteries for 48 straight hours.  I then pulled the corroding battery and installed the new one.  It would not charge properly - having gone through absorption for 2 hours and flotation for 10, it still only had 12.5 V, compared to 13.05 for the other batteries in the string.  I put about 2.5 kW of load on over 8 hours last night, then the battery was at 12.1 V while the other batteries were at 12.35 V.  I then tried the absorption again, and noticed that when I was absorbing at 56.6 V, this new battery only reached 12.9 V.  After going through the whole absorption and flotation process again, it was at 12.65 V.  I would just keep trying for a week or so, but I noticed that the other batteries in the string were at voltages up to 14.9 V during absorption, and I am afraid that could damage them.  I am confused why there should be such a problem with this battery, since the four batteries from the third string I put in last March charged up totally normally and have worked fine since.

Any ideas guys?  The Outback battery expert has not called, emailed or answered my calls.  I got Tech support, but that guy said he had only been working for four weeks and had no idea what was wrong or what to do, but the battery expert could call me, he took down my information but still I have not heard back.  The local installer here in Nicaragua has no idea what to do.

BB.

When you say the questionable battery is at 12.5 volts or so. I guess that is after you have charged it and removed the charger?

What was the charging voltage (setpoint)?

Nominally around 14.75 volts at 25C. And you should hold that voltage for 4 to 6 hours (battery should gas some, and not get too hot).

When the battery has been charging (absorb) for 2 or more hours, what was the charging current?

Nominally, a flooded cell lead acid battery is full when 1% to 2% of battery capacity (100 ah battery, end charge when current drops to 1 to 2 amps).

Bill

Vic

Hi meven..,

Would suggest that you or your installer contact the supplier of this laggard  battery.   Often,  the Warranty would be dealt with through the supplier,   not necessarily with OB.

That said,  why not make a bit of NOISE,  by joining the OB Forum (if you have not already),   and try stirring some action over there?
http://www.outbackpower.com/forum/viewforum.php?f=44&sid=8132e13fcadd8ee196dac8957da673a6

The above Link should be the Topic area for OB batteries.

Sometimes,  conditioning AGM batteries can require a      L    O      N       G     Absorb stage,  to infinitesimally low currents ...   depends upon the exact battery construction.

I am not an expert in these matters.   GOOD LUCK,   Vic

mevenable

These are sealed batteries.  The third string I installed in March were from the same batch, made in Feb 2018.  I had a successful installation experience with those four.  The normal daily sequence is up to 2 hours of absorption at 57.6 V (alternative cut our based on amps if it gets there first) and then flotation as long as the sun lasts at 54.4 V.  I am a member of the outback forum and will also post there.  Thes NC106 batteries are the outback label, and although I understand they sub-contract out for the actual manufacture, there is no way to contact those people

Vic

meven..,

You probably do not have a way to safely charge this single battery that is the new laggard.

But was referring that perhaps this battery has been sitting for a reasonably long time (one might expect that many Rested AGM batteries would have terminal voltage of about 13,  or perhaps 13.1 V,   assuming that these are 12 V batteries.

It is possible that this battery would really "like"   a very,   very long Absorb.

Ideally,   am sure that you would like to just have a fresh new one,   soon ...   just prattling.     Vic

Estragon

My guess is the new battery was, and still is undercharged. 12.4v isn't a fully charged battery.

I'd take the new one out and charge it fully on its own before adding it to the family. Putting in a weak cousin is just going to stress everyone out.

mcgivor

The best solution is to remove it and charge separately, it would never become ballanced, the others will determine when to terminate charging by actually rising in voltage to compensate for the weak link, not good for sealed batteries. The weak new battery would probably fail before the older ones due to sulfation and should never be cycled as this would only manifest the problem. The word best, is used in leu of only, because there are ways around the problem, but it's far easier to charge separately.

mike95490

That "new" battery you got 7 months later, likely sat on the dealers shelf with no monthly top off charge and may be a dud, or you just need to give it a nice long 12V charge by itself.

mevenable

Thanks guys, I have been suspecting that charging it by itself might help, although I am still puzzled by why it will not rise much in voltage during the absorption, but maybe it all relates to that.  Again, this battery is stamped February 2018, four months ago, supposedly when it was manufactured, and in fact the back-order was what caused me not to have three strings from the start - the batteries were purchased in December, but arrived in Nicaragua in March, and the third string was installed soon afterwards.  Again, even those batteries had readings of 12.1-12.5 when I received them, and supposedly according to the manual anything over 12.0 is acceptable, so I used them and had no problem. However, it might have helped that all four batteries in the string were in roughly the same state.  In this case, the battery was from that same February 2018 batch, and started at 12.4, but was in with other batteries that (as per instruction) I had floated for 2 days, and were at 13.05 each.  Supposedly THEY were the weak ones, not this one.  Still, the thing to try IS to charge it by itself, but I have no way of doing that here at the farm.  I contacted my local supplier yesterday to ask if they could try that, and he said he would get back to me, but has not done so yet.  We have a problem here at present that it is dangerous to travel on the roads, so it is unfortunate that the battery was not prepared before I risked the trip to Managua to fetch it.  I just hope these guys step up to the plate now, but I was looking for confirmation from some expert before attempting the trip, to see if it was worthwhile, even if they offered to do it.

Estragon

The problem with charging it with fully charged kin is the charger will only see an overall voltage and charging rate for the bank. As a result, the fully charged batteries get somewhat overcharged, and the weak cousin has charging prematurely terminated. If not corrected, it will eventually sulfate and permanently lose capacity.

An alternative to charging it on its own might be to partially discharge one string to about the same or a bit lower voltage as the weak one, then charge that single string fully. With just one string, there's less "ballast" to prevent proper charging vs multiple strings in parallel.

mevenable

thanks!  will try that!

mevenable

I have another idea - see what you guys think.  If my husband can't find a battery charger in town today, maybe we can disconnect the cables from the charge controller and just connect the cables from the inverter to the battery bank. The house would run on the grid, with the battery bank still available for backup if the grid goes down.  Then I can adjust the CC settings to single battery levels, and charge the new battery using the solar panels.  If I can get the voltage on the battery up to 14.4 V for a couple of hours, it should behave normally when integrated into the system - the problem so far is that when I am charging it as part of the battery bank, it never gets much above 13V even when it SHOULD  be in 14.4 (system is in 57.6)

mcgivor

The battery needs to be charged individually for an extended period until fully charged, 2 hours is not enough, as there is grid available, forget backup, concentrate on the one weak battery. Reconfigure the CC to 12V, if possible, then limit the current input to 10% C at 20h until it regains capacity, whilst not exceeding maximum voltage for the seal type battery, this could take more than 4 hours. Only then should it be reintroduced to a series string and allowed a full charge without any loads whatsoever. Yes it's going to take some time, but always remember haste makes waste.

mevenable

ok, what is 10% C at 20h?  sorry - not sure about that one.  I can only use the CC of course during the day, so really long things would be done over several days with interruptions.  obviously all that disconnecting and changing of settings will be a last resort.  I am hopeful that we might find a battery charger we can buy, and am desperately hoping that the battery guy at Outback gets back to me soon and tells me the exact charging strategy I should use in this case, although you seem to also be offering that, so lets try to get me where I understand what you are suggesting.  It is hard to get much out of Outback.  Outback Tech support already admitted that they can't help me with battery questions and I have to speak with George, but he doesn't ever answer his phone or return emails.  Outback was very supportive up through early April, but they seem to have dropped into a black hole after that - not sure if they are having some problems, maybe a shortage of trained manpower?

mevenable

ah - wait - you mean that the NC106 batteries give 106 Ah if discharged over 20 hours, so 10% of that is a maximum of 10 amps maximum current when charging?

mevenable

ah - wait - you mean that the NC106 batteries give 106 Ah if discharged over 20 hours, so 10% of that is a maximum of 10 amps maximum current when charging?

mevenable

looks like I am off the hook.  The guys from Ecami, the local company, agreed to charge the battery for me, I just have to get it into Managua.

BB.

What is the battery AH capacity... We use the 20 Hour discharge rate (say you have a 200 AH rated battery at 20 Hours... That is 20 hour discharge at 10 amps---20 Hour * 10 amps = 200 AH capacity at 20 hour rate).

So, charging at 10% rate of charge (of 20 Hour capacity) would be 10%*200AH= 20 Amp rate of charge...

For AGM, you would charge at their recomended voltage (say 14.4 volts @ ~25C), and simply let it sit on the charger for upwards of 24 Hours (monitor battery temperature and charging current, and don't let them gurgle or hiss--AGMs/Sealed batteries do not like over charging).

Normally, you would take the battery off charge (or switch to float) at ~1% or so charging current (as battery reaching near 100% state of charge, the battery naturally limits charging current)... 1% of 200 AH would be 2 amps.

However when trying to "recover" an AGM battery, just leave them on "absorb" charging, and the charging current should eventually fall to ~0.1% or even 0.01% rate of charge.

Note, if your battery never drops below 2% rate of charge--It is either about to fail or a failing battery... Over 2% ending charge or float charging current--Batteries will eventually overheat and can even start a fire (in worst case failures).

-Bill

mevenable

The local guys at Ecami just got back to me, the battery is not any good.  That is why it would not charge.  At this point, since I still have not heard anything from Outback, I am SOL.  By the time there are new batteries in the country that I can buy, it will be too late to change them out.  My entire set of 12 batteries is potentially compromised by this, but there is little to be done.  I will just keep cleaning the terminal regularly and hope for the best.

mcgivor

Coat the terminal with Vassaline white, lithium grease or battery post spray, to keep the corrosion at bay.