Adding More Batteries

[farhan]

Hello,

I Want to know can i add 2 more 30 amp/hr SLA batteries with the one AGS 145amp/hr battery i got? i got these batteries free from work but i have heard that we should not mix types of batteries otherwise they do not perform well.

Here in Pakistan electricity goes for 2 hours 3 times a day, its becoming a real head ache but can do nothing. I have a UPS that gives me 1 hour and 30 mins of backup each time the electricity goes, the 145amp battery runs my fan and light for 1 hour 30 mins only. So if i add these batteries in parallel will it work or not? The UPS is designed for 12v.

Thanks,

Farhan

[wooferhound]

I wouldn't mix batteries, different batteries have different charging and equalizing requirements. I run a very large amount of stuff here directly from the 12 volt batteries including lights, fan, modem, TV, and radio. I only get about 30 watts from my solar panels and I have plenty enough power to run these items for a very long time.

Try using car parts directly off of the batteries and you will get longer use from the power you are making. I hope your UPS isn't running off of 24 volt batteries cause it's much harder to locate stuff that works off of that voltage cheaply

[ghurd]

Something is not correct.

Maybe the 145A battery is nearly worn out.

The simplest math says the fan and light are using 100A.

With the Worst choice of fan and a 100W bulb, a 145AH battery should run them for about 4.5 hours.

UPS are not the best or most efficient inverters.

G-

[dnix71]

The batteries "free" from work probably don't have their rated capacity anymore.

If the AGS battery has removable caps to add water, then you shouldn't mix it with sealed batteries. The sealed batteries have to be charged slower because they can't vent as well. You would equalize the AGS flooded cell battery differently than the sla's, too.

I don't know what your budget is, but adding more deep cycle flooded batteries (like the AGS) is the best way to go.

I run a laptop, modem, fan, lights, refrigerator and small inverter from three batteries like your AGS. I only use the inverter for the laptop and modem because the modem and laptop charger need clean AC.

My lights, refrigerator and fan all run from 12 volts directly. That's the most efficient way. If the electricity fails, those appliances never know. All they see is the battery bank.

You should get as many appliance that run directly from 12 volts as possible and get a regular battery charger to quickly boost your battery pack as soon as the power comes back on.

I hear you are about to get a new president. I hope things go better.

[scottsAI]

Farhan,

There is a lot you have not told us.

The UPS is designed for SLA battery, I would not hesitate to add it.

Normally I would not say that, your cycling them quickly, maybe not enough time to fully recharge between cycles.

As wooferhound and ghurd pointed out, one light and fan should not be killing your battery.

12v * 145ah = 1,700watt/hr

USP are not efficient lightly loaded, my 3kw unit draws 50w no load, your battery should run it for hours and hours...

So what is the wattage of the light and Fan?

What model UPS? (need its specifications)

Have fun,

Scott.

[scottsAI]

Dnix71,

Have you looked at a 12v adapter for the laptop? Cost same as small inverter.

Efficiency was better than using small inverter and AC adapter.

My modem uses 12v so run it directly from PC power supply.

Have fun,

Scott.

[dnix71]

My dsl modem runs on ac. If I want to use my external discs, they need clean ac, too.

I use a small pure sine inverter by Aims. Since it's on anyway, I just plug the laptop charger into it, too.

I don't know about efficiency. The Macally ac adapter says it uses 1.5 amp at 110-240vac and puts out 24v at 2 amps, BUT my Kill-A-Watt meter says it's using 15-18 watts with the battery fully charged. If I close the lid, my Apple suspends itself automatically, and the wattage goes up and down for a few seconds, then drops to 3.

The car adapter is Micro Accessories (APD) model DC-72A24. It put out up to 3 amps at 24v. With the battery fully charged, my CenTech (HarborFreight) multimeter says there is about 1.25 amps being used. The battery voltage was 13.1, which works out to 16 watts, same as the MacAlly. The car adapter load senses, too. If I disconnect it from my laptop, the current draw drops to .03amps.

Both adapters are after market. The original Apple adapter is usually left in the box. It has a slightly bent plug, but still works. It also uses 16 watts according to the Kill-A-Watt meter. The bent plug and dinged up laptop shell were from the original owner, who dropped it. The new Apple ac adapters have a magnetic plug, rather than RCA jack, for safety.

I had to replace the hard drive recently because it had accumulated damage from the original fall (lots of bad, unrepairable sectors).

[Tritium]

As one who deals with many DSL modems I can say most run on DC even though they may have a low voltage AC supply. AC Wall Warts are cheaper so the manufacturer uses an AC Wall Wart and puts a bridge rectifier on the board in the modem.

Thurmond

[dnix71]

I opened the modem (an ATM, really). Westell C90-610030-06, Rev H

It has a full wave bridge just above the big round cap on the upper left. I plugged it into 13.2 volts dc from the Harbor Freight pdu and it seems to work fine.

I'm posting using it now. If I get desperate for power, I'll do it that way. What does 10.5 vac work out to full wave rectified? Is 13 dc underpowered?

[Ungrounded Lightning Rod]

What does 10.5 vac work out to full wave rectified?

10.5 * 1.414 = 14.8470

But there's also "droop" due to current pulled from the cap between the peaks.  DC doesn't droop.

There will be a regulator or two downstream to reduce the voltage to what is actually used.  So you're probably just fine.

[dnix71]

Most UPS's I know take a full day to recover the battery. We had one at work that went off for brief cycles all day long because the branch it was on was overloaded by a laser printer when it cycled. The batteries went dead real fast. SLA's can't be quick charged to recover without ruining them.

They gave away the UPS (to me) thinking it was no good. I spent $100 putting two big sla's in it and it worked fine at home for years after backing up my personal computer and ink-jet printer. It was a 1300 va Best Fortress that in a former life backed up an AS400 in the front office.

[farhan]

Thank you all for your comments and sorry for my late reply, as its night here when its your day time.

The specification of the UPS i can't ever get for you because its locally made and sold heere in the market without any details of it. No mention of what type batterries we should attched to it. Everyone uses wet batteries because deep cycle ones are really expensive here and old stuff that has been in the shelves for years. Even if i do buy it, it won't run for more than a year or at most two. So in that cost i can get 3 wet batterries of the same amperage and run them for 3-4 years easily.

The UPS is 600watts and it can run 4 fans and 4 tubelights. Each fan is 80w and each tubelight is 40w. That is what the UPS was made for, it did give me 1 and half hours of backup for 3 fans and a light when the battery was new, but its just year old and the backup is so low. I know that it won't be able to charge again this early because as i told you all that electricity goes for 2 hours 3 times a day. So i can se why the less backup, but the amazing thing is that the UPS says the battery is fully charged and still the same backup. At most when fully charged it gives me 1 hour backup for 2 fans and then i have to close one fan and it run for half an hour more, and with it two small energy saver bulbs of 11w each.

The UPS is on 12v, 600w output. Its also eating up my electricity bill because its always on charging with minimum or no efficiency at all. The only problem i can see is that the battery is fine but the UPS's own efficiency is not giving the backup. The same battery as you all rightly mentioned give 4 hours of backup if attached to a normal 650va, 390w APC or PCM UPS which i have. But those are just 400w and the problem is that the built in charger takes 4-6 hours just to charge a 7AH battery how will it charge the 145ah battery and give results.

The UPS business is hot here because of the electricity problem and the prices are sky high and quality very very low. The things that are being imported here are c grade chinese ups. That you all will call junk. But due to monopoly and the cost of working here people are not ready to import the good stuff because they won't be able to sell it.

I myself imported good quality UPS for computers about 2 years ago and the problems i faced only i know, the junk was being sold like cakes and even if i presented my good quality UPS to them they were not ready to buy from me at my cost price even becuase of the cut they got from the other suppliers.

As for the "free" battery part, Yes free but new.

Yeah atlast we are going to get a new President, hope things work out now but really can't hope too much.

I think i have cleared many points i could, now please can anyone help. I thought of changing the UPS too but the next one will be same too as only those are available here and i don't have more money for a new one again. All i can do is work with the things i have, also trying to build a wind turbine hope it gets ready and works well just to charge the battery and atleast save me from the charges of the UPS's charger eating up my bills.

Thanks in advance to all of you.

[scottsAI]

Farhan,

Your problem is unique as will be the solution.

The 600w UPS can charge fast. (Seems to).

Problem:

600. w: Inefficient after charging and while running in backup.
     
400. w: efficient, takes too long to charge.
     
     

OK,

Use a heavy duty switch to connect to the 600w for charging, once charged switch battery to the 400w APC where the loads are. Turn off the 600w.

My APC 1000w supports changing the batteries while in operation, have tested to verify.

Not the greatest solution, may work for your situation.

Have fun,

Scott.

[farhan]

Thank you for your information.

Problems in Pakistan are always unique : ), coming back to serious point.

The solution you told me can be done but i can't just keep switching things from here to there all day 3 times. I am not home most of the time and my family can't do that.

Yes the 600w locally made UPS charges very fast, even if electricity goes 3 times for 2 hours it seems to give same backup everytime. My APC 1000w is not supporting the big wet battery, starts beeping when connected to it. Should i put thick wires in the PCB for battery? maybe the thin wires are not supporting the 145AH battery?

[scottsAI]

Farhan,

I wired two UPS to one battery, been working fine.

New wires are several times longer, used much heaver wire.

New wires equal the resistance of the original wires connecting the battery.

Also kept both wires next to each other (+,-) minimizing inductance.

You might be able to do something like that with relays.

AGS is a battery manufacture, they specialize in SLA type used in UPS.

Should work if connected correctly to APC UPS.

I connected a flooded Lead Acid battery and it worked.

If not then more information will be necessary to figure out why.

Battery voltage when connected,

How doe the newer ones work with it ect.

Many more.

Have fun,

Scott.