Inverter and Battery Charging Question

Lucas61

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Jun 13, 2014
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retired English teacher (30 years)
I do not really understand your question so I reread your OP. Having stated that you suffer through a lot of power outages, it follows that your inverter attempts to recharge the single battery after every outage. I don't see where "if I have not recharged my inverter's battery one time, why can't I do that?" comes into play. If you are only getting 1 hour of backup power from that battery, it is clearly toast and needs to be replaced. I don't know how your inverter knows to stop charging and report the batteries at 100% so I won't guess. Regardless your battery is charging to no where near 100%. All of the advice given pertains to getting the longest useful life out of your system but once the battery stops working well, there is nothing you can do to "rejuvenate" it. Not what you want to hear but I see a shopping trip in your future. Want your inverter to be able to supply power during an outage for longer that it does now get a new battery. Want to prolong the useful life of your heavily worked battery and enjoy an even longer period of backup power, buy and connect more than one new battery.
You very well may be right. Still investigating. There is a consensus here that when the inverter switches to D.C. that shutdown must occur before the battery reaches < 50% charge. I am reading my manual now, since my inverter is programmable, to find out if there is such a setting and I'll report back. Even if there is such a setting, it could be that it's too late for the status of my present battery. And I don't know what it means when the inverter says 100% charge and I got 18 hours of use a year ago, and now it says 100% charge and I get one hour. Be that as it may, I don't have the money at this time to buy a new battery or batteries, so I'll just have to go without.
 

cavok

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You very well may be right. Still investigating. There is a consensus here that when the inverter switches to D.C. that shutdown must occur before the battery reaches < 50% charge. I am reading my manual now, since my inverter is programmable, to find out if there is such a setting and I'll report back. Even if there is such a setting, it could be that it's too late for the status of my present battery. And I don't know what it means when the inverter says 100% charge and I got 18 hours of use a year ago, and now it says 100% charge and I get one hour. Be that as it may, I don't have the money at this time to buy a new battery or batteries, so I'll just have to go without.
In general, chargers determine the level of charge based on the voltage level of the battery. 100% charged shows the battery is at the correct maximum charge level, but it does not indicate anything about the capacity of the battery. Everyone knows that the more charge cycles on the battery, especially if they have been deeply discharged, the less capacity the battery will now have when fully charged. AGM batteries are more affected by deep discharges than regular lead/acid batteries. You said yourself that you've run the battery down to zero many times. That's probably your problem. You've damaged your battery or just plain wore it out.
 

Seamonkey

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Spending $600 for an AGM battery vs $200 for a standard lead/acid battery doesn't seem very cost effective to me, especially when the AGM batteries are only recommended to be discharged 50% vs 80% for a standard lead/acid and only last one year vs several years. That's a lot of money just to save yourself the "hassle" of adding some water to your battery every once in a while. Just what are you getting for all that extra money?
Lifepo4 batteries are the way to go if you are going to spend bigger bucks. They can be discharged to 20% and have over 4000 cycles compared to only 500 cycles for a lead battery. FYI - 500 cycles on a lead battery is based on not dropping below a 50% rate. If you are dropping to 20% consistently you are not going to get about 250 cycles.

 

Lucas61

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Jun 13, 2014
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Op Summary: I'm calling this a "summary" but it may not be the last word. I read the manual. Fortunately, it's in English, well written, and has lots of diagrams. My model is POWERTEK ECO SW Series, 1.5 KW. I didn't understand much of what I read but what I did read and possibly understand doesn't look good. (1) It says that the battery life is 3-5 years, so take the median, 4, and that's 48 months. Then it says that the battery is discharged/recharged every 4 to 6 months. LOL! What country is that? I think that's the (arbitrary) definition of "normal" use. So take the median, 5 months. Divide 48 by 5 and you get, rounding up, 10 discharge/recharge cycles. What the hell? I discharge/recharge once per week or more! So if I'm reading this right, my battery has reached EOL. (2) In Programming mode, the battery can be set to SLD (lead-acid) or to GEL. Gotta check that as I think my battery is gel. Not sure, (3) Per recommendations here, that I set the shut-off at 50% voltage, the only parameter I found that I think fits that is the one that says "Battery low voltage shutdown setting." Well, the default is 10.0 V which makes the advice here not possible to implement. Further, the range of values I can adjust to is 10.1 - 10.9 V. So the maximum shutdown voltage is 10.9 versus 10.0 V?? Does that really matter? And irrelevant if my battery is EOL. But I'm also preparing for next time. (3) It says that the inverter provides over-discharge protection. Really? So maybe I did have that protection but the battery is EOL. (4) Lastly, there are two different battery low voltage fault codes, neither of which have I gotten.
 
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JD Jones

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I like my NAPA brand. Less rated AMP hours than the Trojan (but cheaper) but they don't seem to need water top offs and I like being able to open 3 cells on the battery at once instead of having to unscrew and screw back 12 individual caps on my 4 batteries
You know you can switch the individuals for the 3 cell set up on most batteries, right?
 

beeza

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You very well may be right. Still investigating. There is a consensus here that when the inverter switches to D.C. that shutdown must occur before the battery reaches < 50% charge. I am reading my manual now, since my inverter is programmable, to find out if there is such a setting and I'll report back. Even if there is such a setting, it could be that it's too late for the status of my present battery. And I don't know what it means when the inverter says 100% charge and I got 18 hours of use a year ago, and now it says 100% charge and I get one hour. Be that as it may, I don't have the money at this time to buy a new battery or batteries, so I'll just have to go without.
If you can't replace your batteries right now, you're better off going without. You are using expensive grid electricity to charge batteries that have high internal resistance and low capacity. You may be experiencing higher electricity bills but not consuming any more than usual in you household.

Disconnect the inverter and make do with the power cuts, I'm afraid.

Buying cheap batteries is a false economy. Cheap batteries work exactly like expensive batteries when they are new. But cheap batteries have less lead on the plates and a shallow sump. The thin lead plates will decay in shorter time and the lead sludge will collect at the bottom of each cell. When that sludge touches the bottom of the plate, it shorts out, rendering that cell inoperative. It will boil the electrolyte if you try to charge it. Additives do nothing to help batteries. Once the lead is dissolved, it's dissolved. The best way to check your battery health is by using an electrolyte hydrometer which measures the specific gravity of the water/acid and gives you an instant determination of its health.

I personally like the green top Interstate 6v lead acid batteries.
 

JD Jones

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If you can't replace your batteries right now, you're better off going without. You are using expensive grid electricity to charge batteries that have high internal resistance and low capacity. You may be experiencing higher electricity bills but not consuming any more than usual in you household.

Disconnect the inverter and make do with the power cuts, I'm afraid.

Buying cheap batteries is a false economy. Cheap batteries work exactly like expensive batteries when they are new. But cheap batteries have less lead on the plates and a shallow sump. The thin lead plates will decay in shorter time and the lead sludge will collect at the bottom of each cell. When that sludge touches the bottom of the plate, it shorts out, rendering that cell inoperative. It will boil the electrolyte if you try to charge it. Additives do nothing to help batteries. Once the lead is dissolved, it's dissolved. The best way to check your battery health is by using an electrolyte hydrometer which measures the specific gravity of the water/acid and gives you an instant determination of its health.

I personally like the green top Interstate 6v lead acid batteries.
I'm a big Interstate fan, but didn't have much luck with the 6V batteries. I barely got 2 years out of a set of 4. Very disappointing.
 
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bachata

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I haven't check the water level in my batteries in about a month hopefully they are ok.
JJ
 

johne

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Who is the most recommended store/company in Santo Domingo for a new installation. I have some time yet as I don't close until April '23 but Iwould like start lining up at least two companies for advise and estimates.
 

Manuel01

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Apr 1, 2009
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Hello All,

This post is directed to those who have a lot of experience with AC/DC inverters (inversores). I know you're out there.
We have power outages every week, often more more than a day. We've run the battery to zero charge many times. It is a PowerTek with a digital readout and one sealed battery.
Sometimes I plan to shut it down when the battery is at, say, 20%, but that's often when we're sleeping with one fan going, and the inverter shuts down when we're asleep with a only a red system light remaining.

Suffice it to say that, after about a year, the battery only holds a charge for about one hour, and that's with everything in the house shut off except for maybe one light and a fan.
So, basically, we have no inverter at this moment.

I'm thinking that the battery has lost its charge capacity even though the readout says 100% charged. Is this what is happening? Is it normal? Where do I go from here? What's the solution?

Many thanks.

P.S. The failure of the electric grid is my biggest gripe about living in this country and probably my biggest complaint. We have gone as long as five days without electricity and many times, two or three days. And that's in Zona Colonial on a main business street. Last weekend we were off for two days. Today we were going into our second day and we were told 48 more hours to repair. That's intolerable. A family member paid someone nearby, who works for CDE, RD$1,500 to do a repair "under the table."

This post is in "living in." If you are planning to move to this country, I would say that a prime consideration in choosing a place is the reliability of the electricity. It can change house by house or block by block. . .
If your Inverter shuts off it does not mean that your battery is at "zero". DEpend on the model of your inverter, they all stut off at arround 11 volt of your battery voltage or at arround 22v if you have a 24v system . I would not recomend sealed batteries because you have no way of checking the charger. With regular batteries, it is very easy to check if your charger is "cooking" the batteries. If you need to add a lot of water all the time, something is wrong. !!! With the Battery prices of today (amost 11,000 for a trojan roja) it makes sence to get a good inverter that manages the charging process correctly. A bad inverter can easy go through a set of batteries a year !!!.
 
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Lucas61

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Jun 13, 2014
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Lifepo4 batteries are the way to go if you are going to spend bigger bucks. They can be discharged to 20% and have over 4000 cycles compared to only 500 cycles for a lead battery. FYI - 500 cycles on a lead battery is based on not dropping below a 50% rate. If you are dropping to 20% consistently you are not going to get about 250 cycles.

Are they available in the D.R. and, if so, where? At RD$275.00/lb. impossible to ship here (for me).
 

Lucas61

Well-known member
Jun 13, 2014
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retired English teacher (30 years)
If you can't replace your batteries right now, you're better off going without. You are using expensive grid electricity to charge batteries that have high internal resistance and low capacity. You may be experiencing higher electricity bills but not consuming any more than usual in you household.

Disconnect the inverter and make do with the power cuts, I'm afraid.

Buying cheap batteries is a false economy. Cheap batteries work exactly like expensive batteries when they are new. But cheap batteries have less lead on the plates and a shallow sump. The thin lead plates will decay in shorter time and the lead sludge will collect at the bottom of each cell. When that sludge touches the bottom of the plate, it shorts out, rendering that cell inoperative. It will boil the electrolyte if you try to charge it. Additives do nothing to help batteries. Once the lead is dissolved, it's dissolved. The best way to check your battery health is by using an electrolyte hydrometer which measures the specific gravity of the water/acid and gives you an instant determination of its health.

I personally like the green top Interstate 6v lead acid batteries.
Thanks for this. I take it that the green top Interstate 6v batteries are not cheap batteries, right? (Your argument was to not recommend cheap batteries < "false economy.") Are they available here? Where? I don't understand using 6v versus 12v. 12v seems to be the standard, so if I wanted to use 3 12v, I would use 6 6v?
 

Lucas61

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Jun 13, 2014
814
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retired English teacher (30 years)
Who is the most recommended store/company in Santo Domingo for a new installation. I have some time yet as I don't close until April '23 but Iwould like start lining up at least two companies for advise and estimates.
I can't give you a solid answer but I can give you some information. The customer service at POWERTEK was excellent. For example, they immediately emailed me a manual in English for my inverter. We had a general electrician friend do the installation for about RD$5,000, labor and materials. We had one error with the inverter shutting down when it shouldn't have. The tech from POWERTEK came out (I had to pay) and he found the problem in 3 minutes: a switch in the breaker box was in the wrong position. However, except for that, our electrician did a proper install. When I finally make a decision on upgrading my batteries I will have no qualms about the POWERTEK tech coming out to do the work even if I have to pay more. For example, there are various functions that I need to have programmed: easy to program but not easy to select the right ones and parameters.
 

Lucas61

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Jun 13, 2014
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OP: General questions/comments added:
A. I'm probably looking at non-sealed lead acid 12v batteries. Besides cost, how do I evaluate how many I need: X specs gives me Y results . . .
B. Three names have come up in this discussion (besides Lifepo4), and these makes seem to be available here: NAPA, TROJAN, (green top) Interstate. As far as I can tell, lead/acid battery technology is old technology and has not changed. What I'm concerned about is a poorly manufactured Chinese product that could be defective or dangerous or below standard. Any QC issues with the above three models? Any reason to believe that one is a superior product to the other?
C. One member suggested using an electrolyte hydrometer. Digital version available? Seems like a good idea to be able to directly measure battery performance or lack thereof which I cannot do with my sealed battery.
 

fuchs4d

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Mar 7, 2004
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Just what are you getting for all that extra money?
Sealed AGM are safe to use indoors. Unsealed batteries must be placed outdoors with increased risc of theft. The majority of people are failing to do proper maintenance resulting in shortened product life. If you have to rely on other people to do the maintenance in the DR chances are high they forget to check the water or do it wrong.

For the extra money you reduce the risc to loose the batteries early.

Alexander