Inverter Question...

Jenny429

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Oct 10, 2005
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I have a 3.*something* Inverter.. I think it's 3.2 or 3.6? I can't remember.. I have 4 batteries. In 1 year (Just after the guarantee was done on them) one battery went bad... I was told that I need to replace all 4 batteries because I can't use 1 new batter with the 3 used ones.. Is this true?

Best place to buy batteries?

Thanks!
Jen
 

cobraboy

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True.

All the batteries need to be close to the same state of condition for the system to work it's best. You could change just one, but the other three will not be receiving the optimal charge, too much or too little...
 

latitude19

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May 29, 2011
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Hey, I'm by no means an expert, however the red Trojan batteries work good for me. I initially bought 4 Trojan batteries for $4,200 pesos each back about 9 months ago at La Fuente Ferreteria in Santiago. Just went to buy 2 more and now 5000 each from them. The first time they gave me a better deal because I had more (4) and said I was using them to help poor people, which was true. Thought I would get the same deal again, but no. Just asked about the price of the red trojan battery here in the large Ferreteria in Sosua, Pappaterra or something like that. They were 5200, around 5000 with discount. Ask for the discount.

I think they sell just a bit cheaper in Price Smart in Santiago. Not really worth the trip for batteries alone.

You need to state in what region of the country you are so people in the same area can point out places to buy them.

I have a 3.*something* Inverter.. I think it's 3.2 or 3.6? I can't remember.. I have 4 batteries. In 1 year (Just after the guarantee was done on them) one battery went bad... I was told that I need to replace all 4 batteries because I can't use 1 new batter with the 3 used ones.. Is this true?

Best place to buy batteries?

Thanks!
Jen
 

Olly

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Mar 12, 2007
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Battery Question ?
I have always found this an interesting point - you must have all the batteries in the same state? Jenny - how were the batteries tested? There is a large box with a meter on it and some battery Clips that the technician puts on the batteries - it indicates good, weak or bad after testing for a about 15 seconds on each battery. Is this what happened when your batteries were tested?
At one year old I think you could probably just replace the one bad one. I have had the same situation twice now and once just replaced the one battery in a string of four. It has worked ok. That was a year ago and batteries were one year old ! Trace 235 - replaced with the same type.
The other situation was where there were 3X4 batteries - three strings of four. They were 3 years old which is about the life of a battery here. Testing them with the device above showed that each string had a weak or a bad battery. By rearranging them it was possible to get two strings of 4 that were good , and four new replacement batteries were put in the third string. It was back to 19 hours on the invertor again. The one good battery was passed on to a friend in need. Now that was 7 months ago and I have just found that one of the old batteries has gone bad. I will replace it with one new one.
So really I am not sure Jenny about replacing all of them.
In my apprentice days - we used to change out the two volt cells in the Telephone exchange with rebuilt or "New" ones in a 48 volt system. So replacing one was a standard practice in those systems but that was a few years ago now!
So my suggestion is give it a try with just replacing one - after all you only have 4000- 5000 RD$ to loose!

Olly
 

Jenny429

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Oct 10, 2005
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You need to state in what region of the country you are so people in the same area can point out places to buy them.

Thanks you gave great advice.. as far as what region of the country, not many people are from here... I'm in Barahona.. I will go to the capital if needed... but I am seeing the same prices here in Barahona so it's good to know! Thank you for all yoru help!
 

Jenny429

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Thank you Olly!! I guess you are right.. I will try the one new battery before replacing them all!! Thank you!
 

Jenny429

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Oct 10, 2005
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True.

All the batteries need to be close to the same state of condition for the system to work it's best. You could change just one, but the other three will not be receiving the optimal charge, too much or too little...
Thank you Cobraboy
 

windeguy

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Jul 10, 2004
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Trying to replace one battery in a chain of four is not the best solution because if all four batteries are not in the same condition, it causes strain on the battery system where one battery is fighting the others, for want of a better explanation.
It is almost impossible to find the same type of battery that is one year old to replace the bad one, so you could give a new battery a try, but make sure it is one of the same type. As was mentioned, it is at most a 5,000 peso risk.

In the future, I also recommend Trojan Red Batteries purchased from Luis Hernandez in Moca or Santiago.
 

Jenny429

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Thank you! I just looked my batteries are "tronic" so my next 4 will be trojan.. I guess I will try the one battery being replaced... It happened so quickly... My batteries don't keep the charge for more than an hour and they tested it with a meter and said the voltage on that ONE battery dropped quickly.. The others didn't..

Thanks!
 

Como_un_cameron

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Jan 8, 2011
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Battery Question ?
I have always found this an interesting point - you must have all the batteries in the same state? Jenny - how were the batteries tested? There is a large box with a meter on it and some battery Clips that the technician puts on the batteries - it indicates good, weak or bad after testing for a about 15 seconds on each battery. Is this what happened when your batteries were tested?
At one year old I think you could probably just replace the one bad one. I have had the same situation twice now and once just replaced the one battery in a string of four. It has worked ok. That was a year ago and batteries were one year old ! Trace 235 - replaced with the same type.
The other situation was where there were 3X4 batteries - three strings of four. They were 3 years old which is about the life of a battery here. Testing them with the device above showed that each string had a weak or a bad battery. By rearranging them it was possible to get two strings of 4 that were good , and four new replacement batteries were put in the third string. It was back to 19 hours on the invertor again. The one good battery was passed on to a friend in need. Now that was 7 months ago and I have just found that one of the old batteries has gone bad. I will replace it with one new one.
So really I am not sure Jenny about replacing all of them.
In my apprentice days - we used to change out the two volt cells in the Telephone exchange with rebuilt or "New" ones in a 48 volt system. So replacing one was a standard practice in those systems but that was a few years ago now!
So my suggestion is give it a try with just replacing one - after all you only have 4000- 5000 RD$ to loose!

Olly

I Agree with Olly,
Try it and you could be fine for 3 more years.
If not... bad luck.

I have an inverter with four batteries, one battery went bad and I took it out and didn't really notice the difference in performance. For now the inverter is running on tree batteries for almost four months.
Batteries are like computer hard drive, you'll never know how long they'll last. Some will last for ten years some will last one hour. Only if you run critical business replace them all at once, if not ....DON'T
 

cobraboy

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Jul 24, 2004
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I Agree with Olly,
Try it and you could be fine for 3 more years.
If not... bad luck.

I have an inverter with four batteries, one battery went bad and I took it out and didn't really notice the difference in performance. For now the inverter is running on tree batteries for almost four months.
Batteries are like computer hard drive, you'll never know how long they'll last. Some will last for ten years some will last one hour. Only if you run critical business replace them all at once, if not ....DON'T
How did you configure your inverter with 3 batteries, assuming 6v batteries? It wouldn't matter if your inverter is 12v or 24v.

If a 24v inverter, it's not possible.

If it's 12v, one battery is twice the capacity as the other.

'Splain me here, please...
 

Como_un_cameron

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Jan 8, 2011
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No S?

A Dominican fixed that, i'm no guru in this matter. But it still works!!
On the other hand why would't it work.
4 12v batts delivering 2500 Watts
3 12v batts delivering 2500x3/4= 1875 Watts

But I'm no Dominican ;)
 

windeguy

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Jul 10, 2004
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No S?

A Dominican fixed that, i'm no guru in this matter. But it still works!!
On the other hand why would't it work.
4 12v batts delivering 2500 Watts
3 12v batts delivering 2500x3/4= 1875 Watts

But I'm no Dominican ;)

Sounds like you are using 12 Volt car batteries that are in parallel.
Although for a short time at La Sirena they did have some 12 Volt deep cycle batteries.
 

Como_un_cameron

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Jan 8, 2011
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Sounds like you are using 12 Volt car batteries that are in parallel.
Although for a short time at La Sirena they did have some 12 Volt deep cycle batteries.

Again I'm no expert.
An inverter just converts 6/12/24 volts into 110 or 220 volts. No more.
Ok the inverter itself is limited to its own maximum of Kwh.
You could use it with one battery and get 2500 watts or even more , but just for a little time. Then the battery is drained.
It's in Kwh Kilowatt an hour like mile an hour:)
Just add more battteries and you'll have more time to use that 2500 Kwh.

Same is for a 10,000 Kwh inverter.
With just one battery you'll cook it in five minutes.
With 50 batteries you'll last a few days.

Let me know if I'm wrong and why please.

I'll respond ma?ana.

Nighty Night.
 

cobraboy

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Jul 24, 2004
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No S?

A Dominican fixed that, i'm no guru in this matter. But it still works!!
On the other hand why would't it work.
4 12v batts delivering 2500 Watts
3 12v batts delivering 2500x3/4= 1875 Watts

But I'm no Dominican ;)
1) Are you sure they are 12v batteries?

2) What is your inverter input/charging output? 12v or 24v?

Because no matter the answers, you cannot effectively hook together three batteries effectively, even in parallel. In parallel, one "bank" would have one battery and the other two. This confuses the heck out of the charger and WILL ultimately kill ALL the batteries prematurely. And the batteries will never have the same level of charge.
 

Olly

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Mar 12, 2007
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Jenny,
Give it a try - one battery - if the others fail make sure you keep the new one but I dont think the others will fail. At one year old the characteristics of the the batteries will not be much different.
There is another side to this discussion. I have found that "Electricians" will recommend replacing all four since this is a safe and lucrative bet on their part. Four new batteries - RD$20000, fitting etc say Rd$3000 - everybody happy - you bet!! Electrician then sells the three "good " Batteries he has just taken out for RD$ 2000 each = RD$6000 , and the scrap battery for RD$300 - Not bad !!!

Happy customer, RD$9300 for the job! Happy "Electrician" - an interesting "SCAM" !!!

Cobraboy and Windeguy - Is anything "Optimum" here !!! I have not come across the situation of a "New" lead Acid deep cycle battery "killing" the older ones in a string. I am just about to try that situation as I cant find a "good" 3 year old battery so I will let you know!

Olly
 

Olly

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Windeguy ,
Are you sure they weren't going anyway!
If you dont have the right tester it is hard to check them!

Olly
 

cobraboy

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Cobraboy and Windeguy - Is anything "Optimum" here !!! I have not come across the situation of a "New" lead Acid deep cycle battery "killing" the older ones in a string. I am just about to try that situation as I cant find a "good" 3 year old battery so I will let you know!

Olly
Happens all the time, Olly. And, yes, there is "optimum" in inverters here if one knows what they are doing.

Ask any guy who works with battery banks, whether land-based or marine.

The issue isn't "new." The issue is resistance to charge. An inverter will only read the average resistance and charge accordingly. Fact is a new battery will have less internal resistance than the old. The "average" of the two is bad for both. One gets overcharged and the others undercharged. That's just how it is (maybe pedrochemical can explain the math :cheeky:)

All the batteries will eventually fail prematurely and you're back at square one.

The best bet is to try to get a good trade in on the three-very possible with decent batteries-and get a new bank of GOOD batteries.

I have an employee in Santiago who would buy two good 1y.o. used 6v deep cycle batteries right now. One of his died.
 

Olly

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Mar 12, 2007
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Cobraboy,
Yes you are right in one way - the newer battery will probably have a lower internal resistance the the older batteries. But most of the Invertors a current controlled charging and each string will develop its own characteristics. A single string of 4 batteries will all have the same current charging them. On the discharge the string will limit what the batteries can give.
The real issue is "How different are one year old batteries " to a new one ! I dont think there is that much difference and that has been my experience.
With the problem I have of new and three year old ones may have some problems - let you know!
But so far I have got 7 months additional time out of 8 batteries (now 3 years 7 months old) at some slight reduction in capacity while the new 4 have been fine.

Olly