UPS usage?

[RAV-65]

Hi all,

went to see some UPS today... saw one that is 500VA ( 300W ) and the box says it last for 15mins if you use it on a PC... I asked the salesman if I use it for something that is less than 20W ( intending to use for my tunzes ) can it last more than 30 mins? he said it is still 30 mins max...

Anyone got info to share on this device? I thought if I use a low wattage device, it should be able to last longer?

[AlfaRomeo]

Yup, if the current draw is less, than the UPS will last longer when running on batteries. That is true for all UPS.

You should be more concerned on the output of the UPS. Issit true sine-wave or modified? Tunzes or any pump for that matter will not work properly if its not a true-sine.

[dt8666]

It will be easy to get longer backup time as long as you have a right UPS that gives full sinewave.

Extending more backup can be done by changing the battery to a car battery. Just need to make sure that it is a 12V type as some UPS do operate at 24V.

I run with APC UPS on my return pump. the last round of power cut in tampines have no effect on me. My wife don't even notice it but the alarm sound do make some noise.

With my car battery and a return pump at 50W+, I tested it to run for 1hr without any issue. Did not try until it drain off but from calculation, it will last at least 4 hrs for my setup.

[weileong]

Becareful if you change to a battery that is too large, you might blow the recharger circuitry.

A car battery is very poor selection for deep cycling application as they are not made for that. Better to buy a deep cycle battery.

[RAV-65]

How do I know if it's sinewave?? Thought of getting APC... I only wan it to run my tunzes...

[dt8666]

Let me know which model you want to get and I can run a check for you.

Deep cycle bat is the best choice but do note that those battey can be more expensive than your UPS!! For Singapore, we all know we are unlikely to have power outtage for more than few hrs so it is still within the safe zone as long as you are not overloading it with too many devices. FYI, those yellow top deep cycle Bat cost more than $200 at least. If budget allowed, the deep cycle bat is the best choice.

For charging, I don't see it is an issue. the in built charger will charge at rated amps, bigger bat will take longer time to charge, that is all. After full charge, it will turn to tricker charge. Many reefer around the world already done that.

Cheers!

[weileong]

You can get a Trojan 150Ah deep cycle wet cell for $150. Can get from YHI.

Car batteries might be cheap but one deep discharge will kill it.

Bigger battery will take higher charging current, this is my experience so if you just post this way w/o any caution then one fine day someone going get a 300Ah battery connect to their UPS and blow up the recharger circuitry. You can upsize a bit but not too big an upgrade.

[dt8666]

Cool price on the Deep cycle batt. 150AH can last me few hours for sure...

Will get one soon....

Thanks.

[dt8666]

BTW, on the note of bigger batt will take bigger charging current should be true for most batt. Or we should say can withstand/take higher charging current. But the charging current also depends on the charging circuit, most of such device are working on constant charging current so not sure why it will blow the charging circuit.

may be the charging circuit can not run for too long and give way since it takes longer time to charge a bigger capacity batt.

For standard UPS that power our stand alone PC, it is only at 10 - 12AH. putting in a 150AH batt is 10 times the normal capacity. I am currently using a 70AH car batt and so far so good.

Don't balme me when you blow up your charger as i just share my 2 cents..

[nakazoru]

UPS can last longer if equipment is of lower consumption. Don't let those sales people confuse you, they dun know shit.

All the 230V UPS definitely gives you 230VAC (alternating current). I do not know about those none industrial grade taiwan or china brand. All UPS I used at work even PC grade APC UPS, delivers what they promises.

If you buy CE certified brand chances nothing will go wrong. But do remember batteries has a limited lifespan. Max 5 years replacement, some 3 years.

I come across many UPS at yahoo auction for S$50 so check it out but low KA. My guess is if you use APC for 20W, it will last 1 hrs to 2.5 hrs, depending on the states of the batt.

[madmac]

It will be easy to get longer backup time as long as you have a right UPS that gives full sinewave.

Extending more backup can be done by changing the battery to a car battery. Just need to make sure that it is a 12V type as some UPS do operate at 24V.

I run with APC UPS on my return pump. the last round of power cut in tampines have no effect on me. My wife don't even notice it but the alarm sound do make some noise.

With my car battery and a return pump at 50W+, I tested it to run for 1hr without any issue. Did not try until it drain off but from calculation, it will last at least 4 hrs for my setup.

dt, can you pls share how this is done. I have a APC SmartUPS 1400VA, are you saying I can connect another battery to it to extend the usage under power outage. Like a special/simple mod done? Thx.

BTW what is deep-cycle mean?

[dt8666]

OK, I just got confirmation that all APC SMART UPS (not the normal backup) supports full sine wave else will be step sine wave.

Bro madmac, you can just replace the current battery to a larger capacity version. the current you have may be around 10AH so changing to a higher AH will provide longer backup time. The "mod" is simple like replacing the current batt to a larger capacity as long as you know the connection and the voltage (12V or 24V).

Do note that your model may be using 24V (normally it is 2 pcs of 12V join in series). other way is to joint multiple battery in parallel to get bigger capacity. make sure you know how to joint the wire and the right polarity. else you may melt the battery and worse cause fire!!! Caution!! Caution!! Be warn now, don't say that I did not say that...

i unable to see your model listed at below link:

http://www.apc.com/support/tech_refs.cfm

Deep-cycle mean the battery can take deep discharge. in the event that your AC main power is not back for extended time, your battery will be drained till it stop. this deep discharge may kill some battery but those deep-cycle battery are design to take those deep discharge. This type of battery also can take larger surge discharge like those car hifi that have surge current due to strong Bass sound.

hope this help.

[madmac]

Thx bro. !

This is my model... it is a discontinued version. : APC Smart UPS 1400INET

So essentially, you saying that this is merely a replacement. I tot, it can be used to extend the live hours of the battery by hooking up to another battery like in parallel, as my current model battery is still working fine. IOW, I should get one compatible battery to go into the casing.

again thx for the explanation.

[tineng]

not sure about APC....but from what i heard, some UPS are designed to cut off after 10 minutes regardless of the charge that is left in the battery.....so even if you change the batt. it might still not work.....

also for controllable tunze, they use a converter to convert AC to DC....this work pretty much in the same concept as your PC so i think those DC pumps would still be able to run on the cheaper step sine wave UPS - any bro can verify this? my knowledge on electrical stuff quite limited....

[RAV-65]

Wah biang... u people are making me confused...

HELP!!!!!

[dt8666]

for battery to go into your current casing will always restricted the capacity. It will need to be external if you do the "mod".

if you have a voltmeter, just measure it and you will know.

Cheers!

[madmac]

The APC SmartUPS uses the RBC7 which is rated 12V/17AH. The tech specs shows only two wires +ve/-ve( RBC7 ).... so in theory, could you hook an external 12V/150AH 'deep-cycle' trojan battery in parallel... let the UPS charge it for you and just leave it... in the event of power failure... you would have a total 167AH... wud that be correct... sorry, my electrical really bad, but it should still work, right? thx.

[ervine]

I don't think you can just rip out an exisiting UPS's battery and replace it with a deep charge battery right? Some of those batteries require rather big dedicated chargers.

As for the true sine wave, it's ESSENTIAL... i blew 2 UPS by running magnetic pumps on them... luckily the manufacturer replaced it and upgraded it for me for free...

I'm using an Ablerex btw... lasts me abt 20mins for 2 small pumps (total abt 70W)

[dt8666]

By theory, you can connect it as parallel as long as it is 12V. I would not suggest you connect the original batt but just one external batt instead. you can keep it as "spare"..

Like I said earlier, I do not guarantee it but I am very happy with my setup now... I am using APC SMART UPS 420 and connect it with a 70AH maintainent free battery.

For added safety, get the ext battery charged before connect it to UPS lar..

Good luck!!

[nakazoru]

Maybe we should also look into backup generator so that power will kick in if there is a prolong trip. Confirm fail safe.

Backup the one most important equipment that will prevent the tank from crashing with UPS. You decide.

If trip happens more than 4 hrs and no one is home, then chances is every thing crashes...

UPS design comes in 2 things, UPS and batteries bank. Need at least a diploma to design one. So just keep it simple. One UPS support one tunze.

Please dun fool around with electrical if you have no idea. UPS and batteries is a combination, both are rated. If you wants the UPS to charge more batteries that it can charge, it will not, if lucky you burn some fuse or burn some PCB. It may also trigger the UPS in bypass with no backup. Most APC UPS is designed to provide enuf power for you to shut down the PC/servers safely, not crashing the PC/servers. It is not a life-support system. Backup generator is a must in hospital, they dun use UPS.