Maintaining UPS/car batteries

[talhawaleed]

Strange Phenomenon

Battery Fully charged and inverter terminated the charging by it self. I turned off main and checked inverter?s output directly from inverter?s AC out let and the reading was 176 V while there was no load on inverter. However, LCD indicator on inverter screen was showing 220 V output.

2nd Step:
I connected the phase wire in inverter?s out put socket and turned on 2x 23 Watts bulbs and inverter showed 184V output voltage in another socket of the room. Gradually volts increased to 192V.
When I tuned of the both bulbs (when there was no load on the inverter it once again shows 179 V in the same socket).
3X 23 Watts bulbs load on inverter, reading in socket showed 195V.
4X 23 watts bulbs load on inverter, reading in same socket increased to 198 V and then I turned on a 40 Watts tube light and volts increased to 205V.
4x bulbs+ 2x tube lights, voltage in socket 202V.
Then turned every thing off, meaning there was no load on the inverter and reading in socket gradually reduced to 179V.
I repeated these steps three times and readings were strange. However, voltage output of inverter seemed to fluctuate while increasing the load or decreasing it. When there is some load on inverter during power outage then output voltage is better as compared with the inverter running without any load.

3rd Step:
2x 23 watts bulbs load on inverter, reading in socket = 191V.
3x 23 watts bulbs load on inverter, reading in socket = 195V.
4x bulbs + one 40 watt tube light, reading in socket = 202V.
4xbulbs + 2x 40 watts tube lights, reading in socket = 199V.
4x bulbs load on inverter and when I turned off both tube lights reading in socket was 212V.
Turned off all loads and reading from socket was once again 179V.

Meanwhile, when main is restored the LCD indicator on inverter shows the voltage which precisely corresponds with the voltage readings in the socket i.e inverter LCD indicator shows 129V as well as regarding on socket shows 128 V or 127V.

However, the reading on battery terminals was 12.3 V during this time.

Well, once UPS experiences increased load then it behaves differently. Manufacturer can only answer this specific reason. What you need to do is, adjust the output of UPS in load shedding up to 250 Volts. Right now Output of UPS is very badly adjusted and this will blow away the laptop chargers, mobile chargers etc. once you have adjusted the output then insert different loads on it and measure the output. It will not drop below 240 Volts. But with passage of time once batteries will discharge then output of UPS will start decreasing until it will reach 220 Volts and may further go down till 210 Volts before shutting down.

I hope, you are following the instructions, rest I don?t think so there is any problem with your UPS system.

[HellsGuardian]

seems like ups is fine, the gravity of my battery has dropped to 1125 in just 3 months. I have taken it to the shop where i bought the battery, he said i will flush and add new fluid and later charge it.

My question is how can a new battery drops gravity so quickly? right now it is in warranty but who knows this might happen again... so i am concerned what actually is the problem

[talhawaleed]

Can be because of only of the reasons 1) Wrong charging rate: i.e very high charging rate 2) Batteries not being charged till proper level. i.e: Level Defined as 14 Volts with one battery UPS and 28 Volts for two battery UPS. 3 months are a very less time to perform flush. Unnecessary flush will never solve your problem, first try to diagnose the issue then move ahead with the solution.

[HellsGuardian]

charging rate is around 5.5, and UPS charges it but battery isnt holding the charge (which shopkeeper said is because of low gravity)... thats the thing, how gravity dropped at first place :S
Having these two ruled out, what else do u think can be causing this problem

[talhawaleed]

charging rate is around 5.5, and UPS charges it but battery isnt holding the charge (which shopkeeper said is because of low gravity)... thats the thing, how gravity dropped at first place :S
Having these two ruled out, what else do u think can be causing this problem

Then Battery is not being charged till proper Level, like i said that it suppose to be either 14 Volts or 28 Volts.

Verify this

[HellsGuardian]

the open circuit voltage should be 14volts? ok i will check

Btw i got the battery recharged from shop and still the UPS voltage (AC) drops to 120-160 when Tubelights or fans are turned on. And there is some weird sound coming from its Transformer. I think its UPS problem, even though you suggested to bring the UPS to college road but due to my busy routine, i was unable to make a visit. Is there anyone you know in isb?

[talhawaleed]

the open circuit voltage should be 14volts? ok i will check

Btw i got the battery recharged from shop and still the UPS voltage (AC) drops to 120-160 when Tubelights or fans are turned on. And there is some weird sound coming from its Transformer. I think its UPS problem, even though you suggested to bring the UPS to college road but due to my busy routine, i was unable to make a visit. Is there anyone you know in isb?

No I don?t have any reference in Islamabad, best is if you can take this to college Road. Output Voltage on UPS line should not drop below 220 Volts otherwise it can easily kill phone adopters, Laptop chargers and TV?s. Once Output reaches 160 Volts then you should also have looked for the Voltage at the battery terminals that could have easily indicated if batteries were being weak or UPS requires adjustment.

[HellsGuardian]

No I don?t have any reference in Islamabad, best is if you can take this to college Road. Output Voltage on UPS line should not drop below 220 Volts otherwise it can easily kill phone adopters, Laptop chargers and TV?s. Once Output reaches 160 Volts then you should also have looked for the Voltage at the battery terminals that could have easily indicated if batteries were being weak or UPS requires adjustment.

I did, battery was still at 12.06volts. And these drops (when tubelight tries to start) had little effect on battery voltage.

You might get annoyed and i know this is beyond my knowledge but i just want to know the exact problem, so that when i go to some repairing shop, they dont charge me for things that are working properly. Also since warranty is about to end in about 20 days, i am bit worried if battery is in bad shape.

One last question, i adjusted the ups so that it kept charging for like 2 hours (battery started feeling warm so i turned it off), and the standy-by voltage on battery slowly dropped from 13.8 to 12.20 volts. I ll check in the morning how far it drops.. So u asked if battery stays at 14volts after full charge, No it doesn't.

[talhawaleed]

I did, battery was still at 12.06volts. And these drops (when tubelight tries to start) had little effect on battery voltage.

You might get annoyed and i know this is beyond my knowledge but i just want to know the exact problem, so that when i go to some repairing shop, they dont charge me for things that are working properly. Also since warranty is about to end in about 20 days, i am bit worried if battery is in bad shape.

One last question, i adjusted the ups so that it kept charging for like 2 hours (battery started feeling warm so i turned it off), and the standy-by voltage on battery slowly dropped from 13.8 to 12.20 volts. I ll check in the morning how far it drops.. So u asked if battery stays at 14volts after full charge, No it doesn't.

I did not say that battery is suppose to stay at 14 Volts as this figure will come down once charging will stop. Nothing to get worried about so only thing you need to focus is that charging should stop once this will hit 14 Volts.
You said that you measured the output Voltage on UPS line which was 140 Volts to 160 Volts AC whereas you corresponding checked the Voltage on batteries which was 12.1 Volts at that instance.

If that’s the case then this means that your UPS is way out of Adjustment and once Voltage across UPS line reaches 220 Volts roughly then Voltage across the batteries should be around 10.5 Volts roughly. That should be the point once UPS should beep and should shutdown.

You have not been able to diagnose your issue properly but still emphasize on getting the batteries replaced as its on Warranty. First diagnose the issue then if the problem is with battery then goto the battery shop. It is very difficult to claim a warranty on battery once you don’t know the real issue. These battery guys are very smart and will blame the issue on UPS. UPS guy will blame the issue on battery and they will make you pay across every corner. Once you are certain then you can argue with the manufacturer. So you have to be certain first and last of all, name “Warranty” is a biggest fraud in Pakistan and this word is used to fool the buyers whereas no one entertains the Warranty. Tell me later if I am wrong ???

[HellsGuardian]

i get it, thanks. First i need to get UPS fixed and then diagnose battery for problems.. Alright thanks a lot for the help

[HellsGuardian]

Ok i will go to college road this evening, should i go to any repair shop or do you recommend some specific shop?

[Khurrammoon]

Hello Talha Bhai, I checked the readings on the battery terminals after charging the battery for approximately 4 hours I turned off the inverter and removed all connection cables and took a reading on 200AH battery terminals which was 13.17 V and after one hour readings was 12.90V (note there was no load on the battery, as all the cables were removed) after one more hour reading was 12.46V and after 28 hours reading was 12.36V. My question is that why readings are automatically dropping on the battery terminals when there is no load? As inverter was also disconnected from the battery. I also checked the internal voltages of individual cells using a procedure like connecting the positive probe of the multi-meter with positive terminal of the battery and then submerging the negative probe of the meter into electrolyte of individual cell, one by one. Readings were as following;
Cell no 1= 1.98V, Cell no2= 4.17V, cellno3= 6.33V, cellno4=8.48V, cell no 5=10.62V, cell no 6=12.76V. To make sure I took readings three times.
After one hour readings were like this( all cables from battery were removed as well as inverter); cell no 1= 1.92V, cellno2= 3.99V, cell no3=6.06, cell no 4=8.13, cell no 5=10.19V, cell no 6= 12.26V.

I also noticed one thing that if battery is full and I only run 23Watts load on inverter for one hour inverter takes 2 to 3 hours to charge the battery before terminating the charging and some times it does not terminates charging at all.

[talhawaleed]

Hello Talha Bhai, I checked the readings on the battery terminals after charging the battery for approximately 4 hours I turned off the inverter and removed all connection cables and took a reading on 200AH battery terminals which was 13.17 V and after one hour readings was 12.90V (note there was no load on the battery, as all the cables were removed) after one more hour reading was 12.46V and after 28 hours reading was 12.36V. My question is that why readings are automatically dropping on the battery terminals when there is no load? As inverter was also disconnected from the battery. I also checked the internal voltages of individual cells using a procedure like connecting the positive probe of the multi-meter with positive terminal of the battery and then submerging the negative probe of the meter into electrolyte of individual cell, one by one. Readings were as following;
Cell no 1= 1.98V, Cell no2= 4.17V, cellno3= 6.33V, cellno4=8.48V, cell no 5=10.62V, cell no 6=12.76V. To make sure I took readings three times.
After one hour readings were like this( all cables from battery were removed as well as inverter); cell no 1= 1.92V, cellno2= 3.99V, cell no3=6.06, cell no 4=8.13, cell no 5=10.19V, cell no 6= 12.26V.

I also noticed one thing that if battery is full and I only run 23Watts load on inverter for one hour inverter takes 2 to 3 hours to charge the battery before terminating the charging and some times it does not terminates charging at all.

If you will read this thread then you will realize that this is not the correct method to check the Voltages of Individual cells. Voltages on battery terminals are suppose to drop the way you have observed and this is normal. You should use hydrometer to measure the Specific gravity and then see the variation in cells. What matters is that battery should be charged till 14 Volts and once this figure is obtained then UPS should stop charging the batteries.

[HellsGuardian]

If you will read this thread then you will realize that this is not the correct method to check the Voltages of Individual cells. Voltages on battery terminals are suppose to drop the way you have observed and this is normal. You should use hydrometer to measure the Specific gravity and then see the variation in cells. What matters is that battery should be charged till 14 Volts and once this figure is obtained then UPS should stop charging the batteries.

Ok i will go to college road this evening, should i go to any repair shop or do you recommend some specific shop?

[marrijali]

tap water is not pure at all... The best source for distill water is the drain from the ac at home...( the water drain from split type or window type units)... And we did used it in our lab experiments and found it better then market available distill water....
And for maintainance free battery the battery dude said pour 2 drops of glycerine in it when its shows weakness.. Is it correct??

[Khurrammoon]

Hydrometer readings. Cell no 1= 1.21, cell no2= 1.21, cell no 3= 1.20, cell no 4=1.20, cell 5=1.20,cell 6=1.20.

My multi-meter is a new one and its readings are accurate. Inverter charges the battery on 13.7V, I have checked that and manual of inverter also states 13.7V. Charging current of inverter is 10 Amps.

[talhawaleed]

Hydrometer readings. Cell no 1= 1.21, cell no2= 1.21, cell no 3= 1.20, cell no 4=1.20, cell 5=1.20,cell 6=1.20.

My multi-meter is a new one and its readings are accurate. Inverter charges the battery on 13.7V, I have checked that and manual of inverter also states 13.7V. Charging current of inverter is 10 Amps.

Specific Gravity seems fine, then what is an issue. Also Charging current is also ok, 10 Amperes for any battery above 100 AH and charging should stop at 14 Volts but if Manual says that it will stop at 13.7 Volts then that’s also fine. Manufacturer has kept it a bit low but you should be ok.

[talhawaleed]

tap water is not pure at all... The best source for distill water is the drain from the ac at home...( the water drain from split type or window type units)... And we did used it in our lab experiments and found it better then market available distill water....
And for maintainance free battery the battery dude said pour 2 drops of glycerine in it when its shows weakness.. Is it correct??

Condensate is even worst the rain water, I don’t know who told you this but you need an experiment. Collect this condensate from Air Conditioner and put it in a Jar. Start to heat the Jar till the time 90 % of the water is evaporated and then see what is left behind.

I cannot comment on Maintenance free batteries as I have never tried them.

[Khurrammoon]

Specific Gravity seems fine, then what is an issue. Also Charging current is also ok, 10 Amperes for any battery above 100 AH and charging should stop at 14 Volts but if Manual says that it will stop at 13.7 Volts then that’s also fine. Manufacturer has kept it a bit low but you should be ok.

The main problem is that inverter keeps on charging the battery and some times it takes 3-4 hours to charge the battery if only 60watts or so load is put on it for half an hour or so. Some times inverter automatically terminates the charge after 2-3 hours and other times it keeps on charging the battery for more than 4 hours then I turn off the input to inverter and then within 3 seconds turn it on then inverter stops charging the battery but some times this technique never works. I cannot understand is there some thing wrong with the inverter or battery? If there is some thing wrong with the inverter then it should never automatically terminate the charging but some times it behaves normally and some times not. However, the main issue which is always consistent is that inverter takes a lot of time to charge the battery.Another thing which I have noticed that if inverter fully charged the battery and terminated the charge and after some times main power goes out for even 5 minutes and there is no load on inverter during that time, and when main is restored then inverter tends to charge the battery for hours instead the ideal scenario should be that it should charge the battery for 10 to 20 minutes or so.

[talhawaleed]

The main problem is that inverter keeps on charging the battery and some times it takes 3-4 hours to charge the battery if only 60watts or so load is put on it for half an hour or so. Some times inverter automatically terminates the charge after 2-3 hours and other times it keeps on charging the battery for more than 4 hours then I turn off the input to inverter and then within 3 seconds turn it on then inverter stops charging the battery but some times this technique never works. I cannot understand is there some thing wrong with the inverter or battery? If there is some thing wrong with the inverter then it should never automatically terminate the charging but some times it behaves normally and some times not. However, the main issue which is always consistent is that inverter takes a lot of time to charge the battery.Another thing which I have noticed that if inverter fully charged the battery and terminated the charge and after some times main power goes out for even 5 minutes and there is no load on inverter during that time, and when main is restored then inverter tends to charge the battery for hours instead the ideal scenario should be that it should charge the battery for 10 to 20 minutes or so.

See, all what you are telling me is very easy to diagnose. Next time, place a multi meter on the terminals of the battery and measure the Voltage. Voltage after two to three hours of continuous charging, Voltage once light has gone for hardly 5 minutes and it?s been hours since inverter still charging the battery. Now, by doing so you will find the real truth behind things such as Maybe UPS is trying hard to take the Voltage above 14 Volts and does not cuts off charging or Maybe charging rate has slowed down in later stages of charging that?s why its taking more time or maybe Variable which sets the cutoff charging Voltage has gone bad and UPS simply does not stops charging. These variable used to adjust the output Voltage, Cutoff Voltages are nothing more the variable resistors and at times they do go bad. Replacement of variable resistors are the only solution but this has to be diagnosed first using the technique as described above. These resistors are worth 30-40 Rs but the technician who will change it for you will try to rip you off.