Maintaining UPS/car batteries

[talhawaleed]

Dear Whiteangel,

CCA, CA, LOAD TESTING, STARTING APPLICATIONS:

Cold Cranking Amperes (CCA) is measure of amount of current your battery can deliver at 0 F for 30 second once both terminals of battery are shorted and voltage does not drop below 7.2 Volts for 12 Volts battery.

Some time battery comes with CA rating with is specified for 32 F. higher the CCA rating is typically used for starting applications but not referred to deep cycle batteries.
Never short your battery terminals as lot of heat is generated during this process and you may end up destroying your batteries but this is exactly what happens once you start your car and this is a typical how a load testing is performed.

AH RATING

Normal batteries available in market comes with AH (AMP HOUR) rating which means that 145 AH battery can deliver 7.2 Amperes for 20 hours before it would need serious charging again or 14.5 AMPS for 10 hours before it requires charging again. AH rating is expressed in number of amperes a battery can deliver for 20 hours which is calculated by dividing AH rating by 20.

DISCHARGING RATE

In order to get the best service from your batteries the batteries should not be discharge more than @ AH/10 which for 145AH battery is 145 AH/10 =14.5 Amperes. But it is ok to discharge a battery with AH rating divided by 6, 4 ,3 so this means that you can discharge your 145 AH battery @ 145/6= 24 AMPS , 145/4=36 AMPS, 145/3= 48 AMPS but don’t expect it to last for 4 hours. In case of UPS, I am unaware how much load you have inserted and number of batteries you are using in parallel or series but you can use Ampere meter to observer the load on your batteries during load shedding and if you see that the rate on each battery is more than try to add more batteries to your UPS as current divides in parallel.

CHARGING RATE

Once you are charging your batteries then right rate to charge a battery is you’re AH rating divided by 10. That for 145 AH battery the right charging rate should be 145/10=14.5 Amperes. Slower charging is good for batteries but you have to prepared before next load shedding. Anything above AH/10 is termed as fast charging which would damage your batteries in long run but you can do it for few times if your are monitoring the process and anything below would be termed as slow charging and I can guarantee that this would prolong the life of your battery.

Remember that your Air Conditioner consumed 8- 9 AMPS of current once the compressor is on so you can very well imagine how much power you are wasting once you are not taking care of your system.

1 YEAR IS VERY LESS TIME FOR BATTERIES TO LAST:

This is abnormal for batteries to last for a year, try flushing the batteries and adopt the same procedure I have told you in this thread and I hope you will realize that your batteries were not dead.

[talhawaleed]

since all the battery wizards are in this thread i have a question.

my car battery has a problem that the water level drops and i have to top it every 2 weeks.
went to the battery guy, as per my knowledge its due to over charging issues(water evaporates).........Charging in my car was 100% fine. battery condition is 100%. battery wala had no explanation for water vanish
what comes in ur mind?

Dear Hashu,
I think your Specific gravity is low as during electrolysis more heat is generated in battery once proportion of distilled water is much more than that of Acid. I hope you know that this ratio should be 66 % distilled water and 33 % Acid. That is why water evaporates more quickly.

Ageing is another factor once you start to lose fluid in Battery.

[hash4u]

Doc, without Amp meter, volt meter, not possible to reply back.
the Battery guys have a meter for dummies in hand. i think it has resistors in it, which puts loads on the system and the needle states if the batter is good, bad,,,,or in replace point.

Talha bhai ty for the rep

[VCheng]

Doc, without Amp meter, volt meter, not possible to reply back.
the Battery guys have a meter for dummies in hand. i think it has resistors in it, which puts loads on the system and the needle states if the batter is good, bad,,,,or in replace point.

Talha bhai ty for the rep

In that case, the assurance that everything is "100%" cannot be relied upon, now can it?

Load testers give only a part of the picture. What I mentioned is also needed information for proper troubleshooting.

PS: BTW, please check your messages.

[Xulfiqar]

Doc, without Amp meter, volt meter, not possible to reply back.
the Battery guys have a meter for dummies in hand. i think it has resistors in it, which puts loads on the system and the needle states if the batter is good, bad,,,,or in replace point.

Talha bhai ty for the rep

thats the carbon pile load tester, it has a knob to apply a resistive load on the battery depending on battery size and see when its amp pumping ability drops below 9.8V - (amp pumping ability example is when your starter starts to crank your engine)

if your SG was out the window or gone for a trip - it will not survive any load test and would also show a surface charge of 13 to 14V sometimes.. (meaning the mixture holds less water and current transfer is limited - this phenomenon may have also sulphated the battery plates) - anyways SG should be checked and the battery temperature stabilised at 30 degree celcius, then slow charged, left alone for 2 hours then load tested 2 times to confirm its dead or not (only if all the cells passed the SG equality test)

Ive built a simple but very dumb battery charger with a light bulb and diode (to convert to DC) to charge a dead battery i have lying around. But the Mrs Department is already finicky with me playing with electricity and acid at the same time.

[18THSEPT]

sir plz pm me ur cell numb ...i really want to talk to u!!

[whiteangel]

@talhawaleed

I tested my UPS battery to check the charging amperes, and strangely, the amperes don't remain constant, the needle fluctuates between 8-12AMPs while staying at 10AMP most of the time.

The voltage test shows 13.28 volts.

I also checked gravity of each cell, it varies between 1200-1250

Do these measurements look ok to you? I don't understand why the charging amps fluctuate, shouldn't they remain constant?

[whiteangel]

I think I might have done the amp measurement wrong. I was using an AC meter with a clamp to measure amps. Although the same meter is good for measuring DC volts, I'm nor really sure if can measure DC amps with the clamp. I guess I will need to check the manual.

I would also be grateful if you can shed some light on how to measure DC amps

[talhawaleed]

Once you have difference in Specific gravity of Acid between cells then this means that your one cell is going bad. Your specific gravity looks ok which shows that your battery is fine. You can buy a Acid with gravity 1280 and next time once you lose liquid then you can pour that inside your battery. You can buy a good quality AMP meter from market which should not cost more than 1000 Rs. For 145 AH battery you charging rate of 10 to 12 Ampers is perfectly fine. I think you have measured the Voltage at terminals once your UPS was charging. Keep a note of your battery Voltage once UPS stops charging your battery. I mean once your UPS is charging your batteries then keep on noting the voltage of batteries. It should stop charging once batteries voltage reaches 14 Volts. Any Voltmeter can measure the voltage in DC and AC. For measuring the battery output your voltmeter should be set at DC and to measure the voltage in your home socket it should be set on AC.

I hope your UPS is not overcharging your batteries. If your batteries are a year old then flush at this point may prove it worth.

[manofpk]

very nice info.. being an experienced individual of working in a chemistry lab... i got the point much better ....

[NightHawk]

Ive been posting time and again that you need to use distilled water to make the battery acid. tap water has chlorine and other salt minerals which upset the mixture and ruins the battery.

I procure distilled water in 5 litre jugs and have a lab supply place that sells me acid not in drums but in 5 litre brown glass bottles - this acid is lab grade, (dont know what the drum is) when I make the acid and pour it into local Pakistani Exide, AGS or FB batteries - They can even start big old diesels in super cold weather - and keep a standing charge of 12.7 or 12.8 volts for about a week before dropping below 12.6V, they give great cranking amps for heavy starting loads. The battery carbon pile tester proves it.

I usually put one bottle of distilled in the freezer to add during mixing to cool down the mixture fast - and I prepare the mixture to 1.270 SG at room temperature, and confirm this by weighing 1 litre of it on a digital scale. I also prefer to use a giant glass tub I have - as the plastic resin drum can etch itself from acid

I buy local batteries dry as the place knows me - and know that I do a far better job than them (they sometimes ask me to prepare some battery acid for their special customers) - and never have had to claim warranty from them.

You should also periodically check your charging voltage on your UPS and see if the mixture is gassing from time to time. I also like to put UPS batteries on spring perches so I can shake them now and then, it evens out the acid mixture when its not gassing - prevents sulphation of the plates

Can u plz tell me from where u procure distilled water and Sulphuric acid in Karachi.

Regards,

[hammadameen]

nice info

[smijaz]

@TalhaWaleed & Xulfiqar

Thanks for sharing and explaining.

Got few questions for you,

I recently purchased two AGS batteries one GL50 for my car and one GX145 for my 700W UPS.

Old batteries lasted 3 year (AGS) in car and 2 years (Osaka IT1000) on UPS they were initially filled and charged with the desi electrolyte (H2SO4 + tap water) which battery walas make.

BUT this time I purchased a carton of Pyro electrolyte directly from pyro Chemicals, Model Town Lahore

It had 24 (0.5 litre) bottles enough for my two batteries. Before pouring it in I checked the SG of the solution from a bottle and it gave a reading of 1.230 at 15C.

I filled/charged the batteries with this electrolyte and placed them into their respective positions.

After a week now I checked the SG on both batteries and results were

Car battery (Fully charged: 14V): 1.250 SG on all cells

UPS battery (Fully Charged: 14V): 1.200 SG on all cells

Charging rate of UPS is 8Amps MAX. charging limit is 14V. backup at 50% load is 3 hours max.

Questions:

Q1. Why the UPS battery is giving lower SG at full charge?
Q2. What is the effect of charging on SG?
Q3. With fast charging at 14Amps can the Sg of UPS battery be fixed to SG 1.250?
Q4. What is the effect of temperature on SG?

Any other tip regarding my issue, is welcome.

[Xulfiqar]

your UPS is not charging the battery properly - the electrolyte is not gassing hence not moving, in effect because acid is heavier its settled low in the battery case - giving you a low SG of the mixture which is available up top the cells

fully charged voltage should be checked after the battery has rested at least 1 hr after charging - and surface charge should be removed too - then check the SG

for a 145 AH battery your charge amps should be 14 not 8.

Ideally your initial SG was perfect for a UPS battery 1.230 but not favourable for an SLI (starting, lights and ignition) car battery which is shocked by the starter everytime you turn the key - the favourable SG for car batteries is 1.270 at room temperature

[smijaz]

your UPS is not charging the battery properly - the electrolyte is not gassing hence not moving, in effect because acid is heavier its settled low in the battery case - giving you a low SG of the mixture which is available up top the cells

fully charged voltage should be checked after the battery has rested at least 1 hr after charging - and surface charge should be removed too - then check the SG

for a 145 AH battery your charge amps should be 14 not 8.

Ideally your initial SG was perfect for a UPS battery 1.230 but not favourable for an SLI (starting, lights and ignition) car battery which is shocked by the starter everytime you turn the key - the favourable SG for car batteries is 1.270 at room temperature

How to remove the surface charge?

[Xulfiqar]

short duration of load - headlamps, carbon pile tester

[smijaz]

Saw this on the net while browsing and thought that it will make sense to share this here

Training Manual

[NightHawk]

Can u plz tell me from where u procure distilled water and Sulphuric acid in Karachi.

Regards,

waiting for the reply.

Regards,

[talhawaleed]

Hello guys,
I did not realize that you people have left few messages for me.

NightHawk

First of all, you can buy pure sulphuric Acid from some Acid shop which must be in interior city market. As far as distilled water is concerned that you can produce it yourself by following the procedure show in simple video posted earlier.

YouTube - Camping Distiller

then you can mix them by following a procedure which I have posted earlier.

smijaz

if you will read this thread again you will realize that our technicians prepare the Acid with gravity of 1280 by mixing the tab water with sulphuric Acid. If you will buy the mixture from them then it wont guarantee that it has been prepared with distilled water. You can confirm this by asking them.

Correct charging rate for 145 AH battery is its amp hour rating divided by 10 which In your case is 14 Volts. You can also charge your batteries with 8 AMPS as slow charging is good for batteries but you have to make sure that you the batteries are fully charged before next load shedding.

Normally SP of Acid within the cell goes up once batteries are charged and goes down once it is discharged. I believe that your batteries do not have a desired SG so adding a Acid with SG of 1300 would be helpful at this stage. Don’t directly add pure Sulphuric Acid inside your battery to increase your SG as that would cause a chemical reaction which would kill your batteries immediately.

Maintain the GS between 1280 to 1250, I hope this will prolong the life of your new batteries. If your SG is low (1100 to 1200) then your UPS will have to put extra energy and time in order to charge your batteries which may even make your battery fat in longer run.

[smijaz]

Hello guys,
I did not realize that you people have left few messages for me.

NightHawk

First of all, you can buy pure sulphuric Acid from some Acid shop which must be in interior city market. As far as distilled water is concerned that you can produce it yourself by following the procedure show in simple video posted earlier.

YouTube - Camping Distiller

then you can mix them by following a procedure which I have posted earlier.

smijaz

if you will read this thread again you will realize that our technicians prepare the Acid with gravity of 1280 by mixing the tab water with sulphuric Acid. If you will buy the mixture from them then it wont guarantee that it has been prepared with distilled water. You can confirm this by asking them.

Correct charging rate for 145 AH battery is its amp hour rating divided by 10 which In your case is 14 Volts. You can also charge your batteries with 8 AMPS as slow charging is good for batteries but you have to make sure that you the batteries are fully charged before next load shedding.

Normally SP of Acid within the cell goes up once batteries are charged and goes down once it is discharged. I believe that your batteries do not have a desired SG so adding a Acid with SG of 1300 would be helpful at this stage. Don’t directly add pure Sulphuric Acid inside your battery to increase your SG as that would cause a chemical reaction which would kill your batteries immediately.

Maintain the GS between 1280 to 1250, I hope this will prolong the life of your new batteries. If your SG is low (1100 to 1200) then your UPS will have to put extra energy and time in order to charge your batteries which may even make your battery fat in longer run.

Thanks for the reply , in my earlier post the one you answered, i have mentioned that I have purchased Battery electrolyte solution of 1.230SG from pyro chemicals, the link of their website is pyro

They claim that they use purified lab grade H2So4 and distilled water.

Other thing is that my UPS has a three stage charging system, with battery standing voltage at <=11V till 12V charging at 15amp, 12V to 13.5 at 8Amp, 13.5 to 14V at 3Amps. It also has a float charger keeping the battery at optimal level without overcharging.

Will try your suggestion by pouring in 1300SG solution to level up the electrolyte and its SG.