[Aroy]

Originally Posted by RajeswaranK7

Hi Guys,
I am looking out to buy an inverter and shortlisted APC 1000VA with two Exide 150AH tall tubular batteries. This is exactly the same setup i have in the ground floor and is performing flawlessly for the past 4 years even withstanding 24hr power outages with 3 fans and or 3 lights and to top that excellent service by the APC personal. Now when i enquired, i am being told that APC 1000VA(BI) inverter is not available anymore and only 850VA pure sine wave model is available. Is it ok to go for APC 850VA sinewave inverter with two APC branded 150AH tall tubular batteries?. I am aware that charging these batteries will take a long time when they are fully discharged, but is there any other issues that I need to lookout for?

Also I am thinking of using two 850VA inverters with one 150AH batteries each, connected in parallel. Can I go for such a setup without any issues?

Help me decide guys .

1. It is not feasible to use two inverters in parallel. To do that you have to synchronize the two outputs.

2. Please check the charging current of the APC inverter, as two 150AH batteries require at least 15+15=30A for a 10 hour charge cycle. In case the current is less the down side is that it will take longer to fully charge the batteries. The upside is that at lower charging rate the batteries wilol last longer

[RajeswaranK7]

Originally Posted by Arch-Angel

Hi Rajeshwaran,

Choosing an inverter depends on what you plan on running during the time when you dont have power. 3 fans and lights can be run with an 850VA inverter. Charging of the batteries depends upon the rectifier specifications given in the inverter manual i suppose.

Originally Posted by Aroy

Please check the charging current of the APC inverter, as two 150AH batteries require at least 15+15=30A for a 10 hour charge cycle. In case the current is less the down side is that it will take longer to fully charge the batteries. The upside is that at lower charging rate the batteries wilol last longer

Thanks @Arch-Angel and @Aroy.

So using two inverters in parallel is ruled out.

I checked the charging specs of the 850VA one and it has a max charging current of 15A, will it be enough to charge two 150AH tubular batteries?

If this current is enough to charge them, is there any special steps to be taken during installation / connecting the batteries?

[Arch-Angel]

Originally Posted by RajeswaranK7

I checked the charging specs of the 850VA one and it has a max charging current of 15A,

Hi Rajeswaran,

With regards to 150AH batteries, 150/15=10h.
That is how long it will take to charge the battery fully to its rated capacity.
If you do end up paralleling the batteries, It will take anywhere between 10-20h since you do not have any circuitry to determine how much a battery has charged and to divert the current to the other battery and vice-versa.

combination setup of invertors can be done. Only thing will be that one invertor can take up running one set of the electrical load while the other takes up the other set (ex: Invertor#1 -> Bedroom1#,Hall invertor#2->Bedroom2# and etc) however, they will be electrically isolated thereby, not parallel in any sense.

A single high capacity invertor with a battery bank is the best way to go though considering a long-term investment.

(Everything listed above is only my opinion, corrections are welcome)

[NPV]

Folks, Need your recommendation/guidance on selection of a battery for use with Inverter.
We have a Su-kam 800VA inverter with a local built (unbranded) 120Ah tubular battery which is now going kaput so looking to replace this with a 150Ah branded tubular battery. I have shortlisted these models, please let me know your suggestions and add any others that are good and not in this list:
1. Exide INVA TUBULAR 500i - Price ~16.5k (one dealer mentioned this model has been problematic and best avoided)
2. Exide INVA TUBULAR IT500 Super - Price ~20k
3. Amaron Tubular CRST - 150 (Short) - Price ~12k
3. Amaron Tubular CRTT - 150 (Tall) - Price ~14k

[sachinayak]

Folks,

I have an 8 year old APC 800 VA Pure Sine Wave Inverter, running on its second set of batteries . Last time, when I had to change my Inverter batteries, I had asked the dealer to provide maintenance free battery, for which he provided Amaron Shield AAM-SH-I0800H29R. Some notes to share around this

• I have 2 of these 100 AH batteries driving my setup. APC folks insisted on having a 2 battery setup as an ideal one.
• I am extremely satisfied with the power back up. My entire house is setup on UPS (excluding the 15A network).
• This setup has worked fine for last 4 years.
• This battery I assume is maintenance free, as I have not done any top-ups since installation.
• Apparently one battery went bad within an year of purchase and was replaced with a new battery by Amaron at no cost. (i personally do not recollect this, but I found that based on the receipts/documentation I have.
• My Inverter is placed in the center of my apartment (in the loft, above the MCB). I had no choice. There is no ventilation for this place.
• Earlier, when we would come home after work (apartment closed for 8 hours), we would get a strong acid gas smell. Switching to the current set of possibly maintenance free batteries has completely got rid of this.
• Earlier this week, my Inverter indicated a failure (am guessing battery problem) and got cut off automatically. My bad, but i tried resetting it twice. On the second instance, one of the batteries exploded right in front of me. After quickly rinsing my face, I inspected the batteries and found a deep crack on both sides of one of them. Some liquid that had leaked out, but the sprays were largely minimized (possibly due to the usage of gel).

With a new baby in the house, I am willing to compromise on battery life (on which I honestly believe anything over 3 years is a bonus) and cost, and hence am very strongly contemplating on replacing the batteries with identical offerings in the market. This should cost me around 12-13K, i guess.

Wanted to take suggestions of fellow BHPians on options that I should consider beyond this?

[aim120]

You should properly maintain the battery by adding distill water every 3 to 4 months.If you don't follow that simple maintenance bad things can happen .Sealed batteries are more likely to explode,since they can't vent out the gases.

[Aroy]

In one of my posts I had given links to Sealed Maintenance Free Batteries (SMF) gas generation and possibilities of exploding. SMF batteries are more delicate and require precise charging/discharging rates, else they go bad.

I suggest that you find a well ventilated place in you apartment and use Tubular Batteries.

[Arch-Angel]

Originally Posted by sachinayak

On the second instance, one of the batteries exploded right in front of me.

The reason that happened was either because of overcharging the battery over a prolonged period of time. Also if the battery was an SMF type, then you should be extra cautious. Since the inverter you mentioned happened to be an 8 year old one, i assume it doesnt have a charging cut-off. The gas generated in usually SMF batteries is contained within the casing, and sometimes, excessive pressure causes the battery container to explode.

Originally Posted by aim120

.Sealed batteries are more likely to explode,since they can't vent out the gases.

Absolutely right aim.

Originally Posted by Aroy

In one of my posts I had given links to Sealed Maintenance Free Batteries (SMF) gas generation and possibilities of exploding. SMF batteries are more delicate and require precise charging/discharging rates, else they go bad.

Tubular batteries from what i have heard from my electrician, is that they are more reliable and robust than SMF batteries. As Aroy had pointed out, SMF batteries do not have vents to let out the Hydrogen gas which gets generated because of electrolytic action between the Lead/Acid. This is the reason its advisable to shut down/disconnect the inverter and the battery while leaving the place for a long time.

Originally Posted by Aroy

I suggest that you find a well ventilated place in you apartment and use Tubular Batteries.

Hydrogen gas generated from batteries, when in sufficient quantities can cause a rather huge explosion if ignited. Therefore it is advisable to keep them in a covered, but sufficiently ventilated place.

[S_U_N]

Originally Posted by sachinayak

Folks,

My bad, but i tried resetting it twice. On the second instance, one of the batteries exploded right in front of me. After quickly rinsing my face, I inspected the batteries and found a deep crack on both sides of one of them. Some liquid that had leaked out, but the sprays were largely minimized (possibly due to the usage of gel).[/list]
With a new baby in the house, ....

I am glad that you shared your experience. I am also glad to note that you are safe and sound after the explosion.

For this reason I have been contemplating on moving the inverter in the balcony. But since the house is on ground floor (and a rental house), I will have to spend money on creating a stand and an enclosure with some locking mechanism. Else anyone can drop in and steal the inverter and the battery.

What material should be used for this?

[sachinayak]

Originally Posted by S_U_N

I am glad that you shared your experience. I am also glad to note that you are safe and sound after the explosion.

Updates.

I replaced the two Amaron SMF Batteries with new ones of the same make (Amaron Shield batteries now are called Amaron Current though). I was pretty satisfied with my earlier set. After replacing the batteries, the setup still did not work and thus my Invertor was inspected. Apparently, there was a short circuit in the invertor, which led it to cut-off automatically. Since i manually tried thrice to turn it on, it led to the battery getting short and thus the explosion. Had i not tried my D-I-Y stuff and had called the electrician, the batteries would have perhaps lasted even longer. Lesson learnt the hard way. Since the invertor was very old, getting spare parts was not possible.

So now i have a brand new APC invertor (BI850 Sine Wave) with 2 Amaron SMF batteries connected in parallel (unlike a series connection earlier). Set me back by almost 20K.

[S_U_N]

Originally Posted by sachinayak

Updates.

w i have a brand new APC invertor (BI850 Sine Wave) with 2 Amaron SMF batteries connected in parallel (unlike a series connection earlier). Set me back by almost 20K.

20K is a good price for the inverter + two batteries.

Did they take the old batteries and deduct some money?

Can you provide a breakup of the costs?

Also, does Amaron offer warranty on SMF battery if it is used in conjunction with an inverter (they expect it to be used with online UPS systems only)?
Have you checked that with Amaron?

[sachinayak]

Originally Posted by S_U_N

20K is a good price for the inverter + two batteries.

Did they take the old batteries and deduct some money?

Can you provide a breakup of the costs?

Also, does Amaron offer warranty on SMF battery if it is used in conjunction with an inverter (they expect it to be used with online UPS systems only)?
Have you checked that with Amaron?

2 Amaron SMF 100AH Batteries (18 + 6 M Warranty) = 13100
APC 850 BI Sine Wave Invertor = 6400
Electrician + Consumables = 400

This was after buying the existing batteries back. Else the MRP of the two batteries was 15K. I did not bargain, as I needed a replacement ASAP. I have had good experience/support with this specific vendor, and thus did not see the need to scout around for further discounts.

Amaron, definitely provides warranty on SMF battery. If you read my first post, I had a battery problem 1 year post purchase (with my previous set) and Amaron replaced it without any charge. I do not exactly recollect this, but my wife does, and I have documents which indicate the same. So must be true.

[manim]

Originally Posted by sachinayak

So now i have a brand new APC invertor (BI850 Sine Wave) with 2 Amaron SMF batteries connected in parallel (unlike a series connection earlier). Set me back by almost 20K.

I also own the APC, but it can charge only up to 180ah with the switch behind it?

(Mine is a 100ah Exide tubular)

[aim120]

Originally Posted by manim

I also own the APC, but it can charge only up to 180ah with the switch behind it?

(Mine is a 100ah Exide tubular)

You can charge a 200ah battery even with 5A setting it will only take 3 times longer to charge then in 15A setting.

SMF batteries have poor life they are not suited for deep discharge or for cyclic use.Discharging SMF batteries to 80 % is enough to reduce its life EXIDE batteries own white papers have this info.

SMF batteries are only suited for short back up application usually in place where there is a genset.

[sachinayak]

While I would agree that SMF batteries are not best suited for invertor applications, my first set of SMF batteries lasted 4 years (and could have last longer had i not fiddled around with the setup). During these 4 years, the setup at home has provide power backup without fuss and for periods significantly longer than all of my neighbors (who stuck on to tubular batteries). I may have been lucky.

That said, I honestly set reasonable expectations (anything above 3 years is a bonus for me) and am a satisfied customer of SMF.