[Thad E Ginathom]

A big [THANKS] to all for the ongoing battery discussion. Really good stuff, and easily readable for the layman

[R2D2]

Originally Posted by prithm

I was wondering, if we don't use any of the appliances (say fans, tubelights since climate is already comfy), what will happen to the battery storage if UPS controller stays on for long powercuts with no appliance drawing anything from it, will the charge still hold good in batteries or will they subsequently discharge since the UPS is still on and monitoring the batteries ?

Even if there is no load, the inverter circuitry remains on and is converting DC to AC and there will be a minor drain on the battery. Of course the batteries will not discharge as quickly as they would had their been a load but they will discharge nevertheless.

Is it OK if we turn off the UPS and turn them back on when we need them for real use (say after sunset and powercut is still ongoing) ?

You can, but what if the power fails at night when you are sleeping? It's a bit inconvenient to get up and switch it back on.

Also, leaving inverter off there is a very small parasitic drain on the battery, called back drain/back flow, which can cause the battery to discharge if the inverter is left off for very long periods of time. Extent of this back drain depends on the inverter, good chargers keep it <1-2 AH per month.

LA batteries last longer when kept at 100% SOC at all times. It prevents plate sulphation. If they drop <80% you need to charge them back up.

I would say leave it plugged in and ready for action. Advantage is your battery/batteries are maintain in top order + it's ready to supply power when needed. Disadvantage is the power consumption. So if you want to save on your electricity bill but don't really care about battery life and backup when power fails switch it off.

My inverter is kept on 24x7x365. The only time I switch it off is when I perform maintenance like disconnecting cables, cleaning terminals etc. It is also left on whilst topping off the DW, I used to switch it off earlier.

[Gansan]

Originally Posted by srikanthns

Noob question : Do these batteries give out any fumes that can affect health? (I mean regular brands like exide, others can / need not). I have Exide inva TUbular 150Ah battery. Now having read something somewhere, my family members are hell bent on throwing the inverter out, telling that my health is more important than the discomfort of being without power.
Is this true, or is it an urban legend?

Originally Posted by JMaruru

Please do NOT keep these batteries in the living area. You could place them in a secluded area, where there is sufficient ventilation and the batteries are well protected.

Originally Posted by R2D2

Emission of gasses is a scientific fact. Batteries emit hydrogen and oxygen during the charging phase a combination we all know is highly explosive in enclosed spaces. Plus if the battery is overcharged it emits hydrogen sulphide which is HIGHLY poisonous and can kill. Lead is a nerve poison and sulphuric acid is both corrosive and poisonous.

Still think it's an urban legend?

So do yourself a favour relocate the batteries to a ventilated place that is cool and dry and away from direct sunlight and the weather. The only type of batteries you can store in your rooms is a VRLA gel cell or AGM batteries. All wet batteries should be stored away from living areas.

The inverter is located in my living room which is well ventilated. It has to be placed there, or in one of the other three bedrooms. There is no other place and I can't place it outside in the common area, which is OTS anyway. All ground floor apartments in my complex face the same situation. People in first floor and above can place it in the balcony.

So what is the solution for us? Can we buy any alternative batteries? I heard the gel batteries have been discontinued.

[R2D2]

Originally Posted by Gansan

So what is the solution for us? Can we buy any alternative batteries? I heard the gel batteries have been discontinued.

Lack of space can't be remedied, so I would only suggest keeping the batteries topped up and keeping the living room well ventilated at least during the day time when the room is in use by family.

TBH gell cells are not meant for Indian conditions. You would experience much lower life as compared to wet cell versions. This and the fact they are more expensive per AH is probably why they are not readily available or discontinued.

[suzuki san]

Hi Guys,

I presently have a 1.5 Kva Microtek inverter with 2 "Okaya" tubular batteries.
The old batteries lasted 6 years and were replaced 2 years ago. So far the Inverter which is now 8 years old has been O.K. Seamless changeover from "Mains" to "Inverter" power. We never even knew when the power had gone.
However, recently I have noticed that there is an appreciable gap (about 1 or 2 seconds) between when the power goes off and the inverter kicks in. Is this a problem with the Inverter?

It is extremely annoying as the TV and set top box switch off and then the set top box takes another minute to reboot and display the picture. Needless to say this usually happens at a critical moment in the game one is watching!

Any suggestions as to a better Inverter with good warranty and after sales service - especially one which has a display showing digital readouts of charging status and back up time left would be handy.

Regards.
SS

[prithm]

Originally Posted by R2D2

You can, but what if the power fails at night when you are sleeping? It's a bit inconvenient to get up and switch it back on.

thank you R2D2-san. It is always a pleasure to read your response.

In this particular scenario, during Vardah cyclone, we were without power for 8 days. And in some locations for nearly 2 weeks. Thus, it became a ideal evil playground for ill-minded humans to take people for ride. For example offering to charge mobiles and electrical devices for Rs.1000 for 15 minute diesel generator output. Mobile network in our area was knocked out for nearly 10 days.

Thus, long story short. If I have to save battery juice during such calamities, what is the ideal standard ops protocol ?

In my limited knowledge, I felt that it can be turned off during daylight and can be switched back on after sunset with limited draw by using 1 or 2 tubelights, 1-2 fans.

My other doubt is, if I turn off and turn on the UPS as the power drains off during this calamity period (with little to no chance for a recharge), will it use up more battery juice ?

[Prowler]

Originally Posted by suzuki san

However, recently I have noticed that there is an appreciable gap (about 1 or 2 seconds) between when the power goes off and the inverter kicks in. Is this a problem with the Inverter?

It is extremely annoying as the TV and set top box switch off and then the set top box takes another minute to reboot and display the picture. Needless to say this usually happens at a critical moment in the game one is watching!

Many home inverters have an option - Inverter/UPS mode switch. If you select the UPS mode, it will try to switch on within narrow specification : input voltage range would narrow to 180 instead of the usual 200 V. What this means is your inverter would switch early thus avoiding a reboot for your sensitive electronics. Look for such a switch at the back of the inverter.

Originally Posted by prithm

Thus, long story short. If I have to save battery juice during such calamities, what is the ideal standard ops protocol ?

In my limited knowledge, I felt that it can be turned off during daylight and can be switched back on after sunset with limited draw by using 1 or 2 tubelights, 1-2 fans.

My other doubt is, if I turn off and turn on the UPS as the power drains off during this calamity period (with little to no chance for a recharge), will it use up more battery juice ?

When an inverter/UPS runs off its battery, whether it supplies power or not to the connected equipment, it will consume certain amount of power - quiescent current and depending upon the power supplied, it may even run a fan to cool the power electronics. This consumption depends upon the design of the inverter. Thus if you want to extract the maximum 'juice' run the inverter only when you need it and at the time you need it.

The inverter has a built-in safety electronics to protect the battery from deep discharging. So don't worry about the number of times you turn it on.

But once the battery voltage comes down to a minimum threshold level, the inverter/UPS won't turn on.
During the Vardah time, I recharged my inverter battery by running a cable from my car battery and running the engine for a few minutes. Fortunately my inverter is of the 12 V type.

[Thad E Ginathom]

How about connecting the battery to a trickle charger? Any difference to letting inverter do thatt job?

[Prowler]

Originally Posted by Thad E Ginathom

How about connecting the battery to a trickle charger? Any difference to letting inverter do thatt job?

A trickle charger as the name implies charges the battery with less than 5 A. Usually they are rated even less than 5 A. Normally you use a trickle charger to keep the charge level topped up. An inverter will have the capacity to charge the battery even when the battery's charge is depleted which will take 10 A or more.


It is another reason why your car's alternator works extra hard when the battery charge level is low. Sometimes the diodes in the alternator fail due to overheating when they are asked to charge a depleted battery under adverse conditions.



It is a good idea to keep the AC/head lights off for some time when you drive a car that has not been running for some time. This way you reduce the maximum current the alternator has to produce to some extent. I have deliberately kept the actual calculations out of this so that it is easier for everyone to understand without getting overwhelmed by the technical bit.

[Thad E Ginathom]

Originally Posted by Prowler

A trickle charger as the name implies charges the battery with less than 5 A. Usually they are rated even less than 5 A. Normally you use a trickle charger to keep the charge level topped up. An inverter will have the capacity to charge the battery even when the battery's charge is depleted which will take 10 A or more.

I am thinking of the case where the inverter is not in use. Whilst the whole thing could simply be taken out of circuit, I think many have a bypass switch. I assume this still keeps the battery charged without the overhead on the power used?

It is another reason why your car's alternator works extra hard when the battery charge level is low. Sometimes the diodes in the alternator fail due to overheating when they are asked to charge a depleted battery under adverse conditions.

It is a good idea to keep the AC/head lights off for some time when you drive a car that has not been running for some time. This way you reduce the maximum current the alternator has to produce to some extent. I have deliberately kept the actual calculations out of this so that it is easier for everyone to understand without getting overwhelmed by the technical bit.

I thought that, once battery was fully topped up after starting, all the car's power needs were met only by the alternator?

Oh, wait. I think I see: you are talking about the period during which the alternator has to meet those needs and charge the battery?

[theredliner]

Originally Posted by gopalnayak

24V model is better. The 24V model would be much more efficient. With 12V, the current drawn from the battery would be substantially higher while delivering the load. There will be good amount of losses in the cable itself. In addition, the losses in the internal devices would also be higher.

Originally Posted by Holyghost

Higher the voltage, lesser the Current (Ampere); which in turn benefit in the form of thinner cables, circuits and lesser losses in efficiency. When you switch from 12v to a 24v system, the current reduces by half and hence easier for the manufacturer to design the internal components which needs to handle only half the current.

Thank you. I ended up buying the 24V one as it'd not be possible to find a 12V replacement in case the current one conks off or if I end up upgrading to a bigger inverter a few years down the line. In either case, I'd have to buy another expensive 200+AH battery unnecessarily if I'd have to upgrade from 12 to 24V.

[Prowler]

Originally Posted by Thad E Ginathom

I am thinking of the case where the inverter is not in use. Whilst the whole thing could simply be taken out of circuit, I think many have a bypass switch. I assume this still keeps the battery charged without the overhead on the power used?

Yes. You could do that. But it would be a waste of time. An inverter's charging circuit will deliver the full current until the battery is fully charged and then changes to trickle charge mode by itself. So why bother with another trickle charger ?


But there is a caveat. If the batteries are in the last legs, the charger will continue to supply higher current. You can notice that the battery will run hotter than usual.

I thought that, once battery was fully topped up after starting, all the car's power needs were met only by the alternator?

Oh, wait. I think I see: you are talking about the period during which the alternator has to meet those needs and charge the battery?

Theoretically if the battery is within specifications and is fully charged, cranking a car engine takes little power (the amperage may well run into a hundred or so Amp) which can be quickly replenished by the alternator within a few minutes. But if the battery is deeply discharged, it will take more than an hour.

Car alternators are sized depending upon the electrical load in the car. For example, a maruti 800 's alternator is rated at 45 A whilst that of a Tata Safari is rated at 135 A. In terms of power in W, Maruti 800 can supply a maximum of 540 W whilst that of Safari can supply 1620 W - all in theory. Your actual mileage may vary (cliche).

[PGA]

A noob question, Can I use RO water to refill the battery.

I feel the aim of distilled water to refill lead acid battery is to provide a sterile medium for ions to move. RO water is close to distilled water in terms of sterility.

Apologies, if its a repeat query as I couldn't search the thread properly, its not showing results with 'RO/water/refill/recharge'.

[saket77]

Originally Posted by PGA

A noob question, Can I use RO water to refill the battery.

I feel the aim of distilled water to refill lead acid battery is to provide a sterile medium for ions to move. RO water is close to distilled water in terms of sterility.

Apologies, if its a repeat query as I couldn't search the thread properly, its not showing results with 'RO/water/refill/recharge'.

Short answer- NO. Because RO water used for potable purpose has a TDS level of anything between 80-120; where as pure distilled water has TDS close to 0. Any TDS in water will damage the battery plates.

Regards.

[PGA]

Originally Posted by saket77

Short answer- NO. .

Thanks a lot. Will stick to distilled water.