inverter or battery issue

Started by comanche, December 01, 2013, 09:31:22 PM

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comanche

I have been having an issue with my batteries seeming to drain quickly. Before getting into specifics, here's what my system consists of:
(4) Trojan L16 - purchased 4 months ago
Xantrex inverter/charger freedom sw 2012
solar not hooked into system yet
Honda 2000 watt generator

loads:
led lamps used sparingly
tv - 6 hours per week
a cell phone or laptop charger here or there

Charge settings:
battery capacity: 600 ah
Recharge volts: 12.2 volts
Absorption Time: 180 min
Low Battery Cutout 10.5 v

mostly we are using propane for lights, fridge, etc.

The issue: during the times we are not even using electricity and the system control panel shows no loads, the inverter will still kick on every few hours. The batteries seem as though they needed a charge every 3 days. I did a complete system reset and also, per dealer recommendation, did 3 equalization cycles. I am not seeing improvement with the capacity of my battery bank, though it does seem like the inverter randomly kicks on anymore.
Honestly, for a while we were using just a deep cycle battery and getting about the same results. The last time I charged, I checked with the hydrometer after charging and it was about 1250 - seemed like a good charge. But, a day later and its down to about 1190.
If anyone has dealt with the before, or have any clues where to look, I'd appreciate it.

Homer, AK

MountainDon

Quote from: comanche on December 01, 2013, 09:31:22 PM
I checked with the hydrometer after charging and it was about 1250 - seemed like a good charge. But, a day later and its down to about 1190.

Is the hydrometer reading temperature corrected? Hydrometers are calibrated for use at the standard test conditions of 77 degrees F. That is the temperature at which battery capacity is rated. To make things easy that is usually rounded to 80 F.    From Trojan batteries...
"For every ten degrees above 80oF add 3 points to the hydrometer reading.

Example: @ 90oF the hydrometer reads: 1.250 The actual reading: 1.250 + .003 = 1.253
For every ten degrees below 80oF subtract 3 points from the hydrometer reading.

Example: @ 70oF the hydrometer reads: 1.250 The actual reading: 1.250 - .003 = 1.247 "

~~~~~~~
A hydrometer reading of 1.277 or greater indicates full charge according to Trojan data. So a reading of 1.25 is indicating a battery not fully charged.  1.25 at STC would be only a 90% charge.  A reading of 1190 is only 40% at STC. It's not clear from what you say whether or not the drop to 1190 happens with no use or if that is the reading after a day worth of use. ???

Often when batteries are generator charged they never really reach 100%. 

What readings did the batteries achieve after the equalization cycles... were all cells equal?

~~~~~~~
The fact that the inverter kicks on when there are no apparent loads makes me wonder what is going on. Are there devices like TV's with remotes connected to the mains? Small FL lights and chargers left plugged in when not charging their devices can be problematic at times? I'm not familiar enough with that inverter to know if the trigger threshold is programmable. If so a higher threshold might help.

Just because something has been done and has not failed, doesn't mean it is good design.


comanche

#2
Quote from: MountainDon on December 01, 2013, 10:35:59 PM
Is the hydrometer reading temperature corrected? Hydrometers are calibrated for use at the standard test conditions of 77 degrees F. That is the temperature at which battery capacity is rated. To make things easy that is usually rounded to 80 F.    From Trojan batteries...
"For every ten degrees above 80oF add 3 points to the hydrometer reading.

Example: @ 90oF the hydrometer reads: 1.250 The actual reading: 1.250 + .003 = 1.253
For every ten degrees below 80oF subtract 3 points from the hydrometer reading.

Example: @ 70oF the hydrometer reads: 1.250 The actual reading: 1.250 - .003 = 1.247 "

~~~~~~~
A hydrometer reading of 1.277 or greater indicates full charge according to Trojan data. So a reading of 1.25 is indicating a battery not fully charged.  1.25 at STC would be only a 90% charge.  A reading of 1190 is only 40% at STC. It's not clear from what you say whether or not the drop to 1190 happens with no use or if that is the reading after a day worth of use. ???

Often when batteries are generator charged they never really reach 100%. 

What readings did the batteries achieve after the equalization cycles... were all cells equal?

~~~~~~~
The fact that the inverter kicks on when there are no apparent loads makes me wonder what is going on. Are there devices like TV's with remotes connected to the mains? Small FL lights and chargers left plugged in when not charging their devices can be problematic at times? I'm not familiar enough with that inverter to know if the trigger threshold is programmable. If so a higher threshold might help.


I did account for temperature when measuring with the hydrometer.
It drops down to 1190 with use, albeit minimal. I have the charger on it now and will check all batteries when done. After equalization all cells were close to the same, within .01.
TV is only devise with a remote and we unplug that daily. We have been unplugging everything except for lamps now and they don't have any lights that stay on even when the bulb is off it would seem.
I'll update with levels once it is done charging tonight.
Homer, AK

comanche

So after a full charge, I let it sit for a bit and the inverter kicked back on. It stayed on for about 30 minutes until finally I got up and manually shut it down. I checked the levels this morning. 1194, 1219, 1209, and 1204. Another round of equalization? That still doesn't explain why the inverter is kicking on and sucking all the juice.
Homer, AK

upa

Quote from: comanche on December 01, 2013, 09:31:22 PM
The issue: during the times we are not even using electricity and the system control panel shows no loads, the inverter will still kick on every few hours. The batteries seem as though they needed a charge every 3 days. I did a complete system reset and also, per dealer recommendation, did 3 equalization cycles. I am not seeing improvement with the capacity of my battery bank, though it does seem like the inverter randomly kicks on anymore.
Honestly, for a while we were using just a deep cycle battery and getting about the same results. The last time I charged, I checked with the hydrometer after charging and it was about 1250 - seemed like a good charge. But, a day later and its down to about 1190.
If anyone has dealt with the before, or have any clues where to look, I'd appreciate it.

So if I read your battery bank correctly you have 2 parallel 12 volt strings at 600 amp/hr or 7200 watts of stored potential. Looks like your 12v inverter uses 30 watts/hr in standby mode or 2160 watts(or a 30% DOD) over 3 days without any loads. So assuming your "full" charge is really more like 90% SOC as Don suggested you are really dropping closer to a 60% SOC over 3 days again assuming no loads. Maybe I am missing something but based on the initial numbers its not surprising you need to recharge every 3 days.

I am not really sure why the inverter is coming out of standby in absence of any loads, probably would be helpful to get a DC clamp meter and see what the actual power draw is on the battery bank during this period of inverter activity, if its aberrantly high in absence of any real loads I think the inverter is more the culprit than your battery bank .


OlJarhead

Hydrometer readings are only really any good if the batteries were fully charged and then disconnected from the load (and charge) and let rest for at least 6 hours (many call for 24).

Having said that your system is a 12v system?  are these 6v L16's?  300AH each?  etc. 

Have you used Don's spreadsheet to calculate usage etc?

What is the temp?

comanche

Just rechecked the batteries after charging 48 hours ago and shutting inverter off shortly afterwards. 1195 1216 1221 1221. Is that normal for them not to reach close to full charge? I'm new at the batteries, but trying to understand it. The temp is at 57 degrees. During the day it's likely around 50-55 as we don't have supplemental heat.

The system is 12 v. Batteries are 6v 420 ah.

I'll pick up a dc meter and check out the loads. For now I am just switching on the inverter when needed...

Thanks
Homer, AK

OlJarhead

Quote from: comanche on December 04, 2013, 12:18:52 AM
Just rechecked the batteries after charging 48 hours ago and shutting inverter off shortly afterwards. 1195 1216 1221 1221. Is that normal for them not to reach close to full charge? I'm new at the batteries, but trying to understand it. The temp is at 57 degrees. During the day it's likely around 50-55 as we don't have supplemental heat.

The system is 12 v. Batteries are 6v 420 ah.

I'll pick up a dc meter and check out the loads. For now I am just switching on the inverter when needed...

Thanks

Are those SG readings?  If so, from only 4 cells? 1.195 1.216 1.221 1.221 -- if that's 48hrs without a load the first though I have is that you have one poor cell in there (the 1.195SG cell is out of sync with the others).  How long did you equalize?  Did you run it at 15.5vdc?  Check water?

MountainDon

12 cells all together... looks like 4 sp gr readings.... I am confused by that  ???
Just because something has been done and has not failed, doesn't mean it is good design.


comanche

#9
Yes, sorry, 4 separate sg readings. One from each battery. Am i supposed to check all 3 of the Cells on each battery? Oops, still learning   d* here they are-
Battery 1- 1.185 x3
Battery 2- 1.220, 1.215, 1.205
Battery 3- 1.200, 1.185, 1.185
Battery 4- 1.195, 1.200, 1.200

Last night was the first night we used the inverter/batteries since the charge 48 hours prior. Switched it on for a movie, didn't seem like the fan was on for more than 5 minutes tops. Kept it on over night, tv unplugged, no loads. Fan seemed to be running constantly overnight. Turned inverter back off this morning.

Last week I equalized for about 5 hours, three times. Until my control panel switched to float charge. Yes it was at 15.5 v. Water is good.

I'm beginning to think inverter is defective, though I am starting to feel like that myself.  :-\
Homer, AK

OlJarhead

5 hr equalize?  Seems too long.  Can cause damage.

I believe I read not to EQ for more then 4 hours and I only ever go 2 hours (which seems to be ok).

Those readings look like batteries that need to be equalized but I WOULD NOT do it now.  You've done more then you should (I think Trojan recommends once every 28 days but others I've spoken to say that's a little too much).

I'll have to check Trojans site as they have good info there but I'd be worried about that much over charging.

MountainDon

Quote from: comanche on December 04, 2013, 12:18:52 AM
Just rechecked the batteries after charging 48 hours ago and shutting inverter off shortly afterwards. 1195 1216 1221 1221.

From that I am not sure if you mean you charged the batteries, let them sit with no loads at all for 48 hours, and then got those sp gr readings.   If there was no use in that interval there is something going on that is not good.              Q? ... those are the actual or the temperature corrected readings?

Just because something has been done and has not failed, doesn't mean it is good design.

MountainDon

Quote from: comanche on December 04, 2013, 10:54:05 PM

Last night was the first night we used the inverter/batteries since the charge 48 hours prior. Switched it on for a movie, didn't seem like the fan was on for more than 5 minutes tops. Kept it on over night, tv unplugged, no loads. Fan seemed to be running constantly overnight. Turned inverter back off this morning.

Seems to me that there is something wrong with the inverter. Why would it hardly run the cooling fan while you watched a movie and then when you unplug the TV, etc. the cooling fan runs and runs and runs??  That's not right. Under light "normal" loads our inverters fan never runs.
Just because something has been done and has not failed, doesn't mean it is good design.

MountainDon

Trojan has the following statement regarding equalizing... "Many experts recommend that batteries be equalized periodically, ranging anywhere from once a month to once or twice per year. However, Trojan only recommends equalizing when low or wide ranging specific gravity (+/- .015) are detected after fully charging a battery. "

More on their view of equalizing at...
http://www.trojanbattery.com/batterymaintenance/equalizing.aspx
Just because something has been done and has not failed, doesn't mean it is good design.


MountainDon

Re: the cell readings. Cell readings, all of them, are more meaningful than a random or same cell from each battery. All cells can give an indication of battery health.  The individual readings should not vary as much as those you published do. Battery 1 is much lower than the rest and battery 3 has a wide enough spread to warrant an equalization.  That does not seem right to me?


Have you ever gone over to the AZ Wind-Sun alternative energy forum?  They have some good folks over there. I'd try running the scenario by them. Spell out all the details and see what they say about the batteries in particular. And unless I am missing something I believe they will come to the same conclusion that the inverter is behaving badly.  Then let us know what they say or post a link back.
Just because something has been done and has not failed, doesn't mean it is good design.

comanche

Thank you, I have also been dealing with the distributor and manufacturer and hopefully can get it switched out if it is indeed the issue. Xantex is trying to tell me it's normal, but the distributor seems to agree this isn't. I have noticed it is sporatic, which will likely make it more difficult to diagnose/fix. I'll head over to AZ wind-sun as well and see if they have any advise to offer. Thank you.

Homer, AK

OlJarhead

Quote from: comanche on December 06, 2013, 06:44:11 PM
Thank you, I have also been dealing with the distributor and manufacturer and hopefully can get it switched out if it is indeed the issue. Xantex is trying to tell me it's normal, but the distributor seems to agree this isn't. I have noticed it is sporatic, which will likely make it more difficult to diagnose/fix. I'll head over to AZ wind-sun as well and see if they have any advise to offer. Thank you.

The fan on my AIMs only runs under a load.