Buying a UPS

[TehStranger]

Well, inverters are rated by their output power, so this inverter is capable of delivering 1200W output. At 80% efficiency, that equates to 1500W draw from the batteries and 300W loss. In your equation, your inverter is 125W efficient.

1500w/24V = 62.5A

If you draw 400W on the AC side, then the inverter will draw 500W from the batteries:

400/0.8 = 500W.
500/24 = 20.93A
So 100Ah batteries should last 4.8 hours, but you only want to go to max 50% of that = 2.4hours (50% DoD)

Right so, get 2 x 100Ah batteries and use Inverter for 2 hours to be on the safe side. For load shedding longer than 2 hours I should plug the generator into the inverter and carry on as usual.

Now, what batteries to get? Anyone have suggestions?

/Goes off to do more research

 

[P924]

Right so, get 2 x 100Ah batteries and use Inverter for 2 hours to be on the safe side. For load shedding longer than 2 hours I should plug the generator into the inverter and carry on as usual.

Now, what batteries to get? Anyone have suggestions?

/Goes off to do more research

Look at either omnipower or Ceil batteries.

 

[verge]

Advice for running wifi router only.

I want to add a UPS/battery with charger to my wifi adsl router to keep it running during load shedding (say 2.5 hours) and would appreciate any advice. I have read the whole thread and it seems some people are managing this with a 650 UPS. Other threads on this forum say that since the router is 12v that the best solution would be a good battery with a charger. What would be best? I am willing to spend up to R1200 but less would of course be better. The solution needs to be neat since the router is in the family room - which is making me lean towards a UPS - but from what I have read here it seems that UPS devices are not designed to last for 2.5 hours even under a small load. If possible I would like to connect a light (possible LED) to the same UPS/battery.

 

[Tinuva]

What manual?

The booklet that come with it when you buy it. It is white paper, with black printed text on it. Don't think I can more accurately describe it than that.

 

[Dan C]

I want to add a UPS/battery with charger to my wifi adsl router to keep it running during load shedding (say 2.5 hours) and would appreciate any advice. I have read the whole thread and it seems some people are managing this with a 650 UPS. Other threads on this forum say that since the router is 12v that the best solution would be a good battery with a charger. What would be best? I am willing to spend up to R1200 but less would of course be better. The solution needs to be neat since the router is in the family room - which is making me lean towards a UPS - but from what I have read here it seems that UPS devices are not designed to last for 2.5 hours even under a small load. If possible I would like to connect a light (possible LED) to the same UPS/battery.

I run mine on a UPS (1000) and lasts the whole time (and running an led light). The only problem is that Telkom ADSL dies about 15mins into loadshedding , so it does not really help me much.

 

[Gtx Gaming]

I run mine on a UPS (1000) and lasts the whole time (and running an led light). The only problem is that Telkom ADSL dies about 15mins into loadshedding , so it does not really help me much.

My 750va from makro use to do the full 2.5 hours.

2 months later it is only good enough for 50 min.

 

[furpile]

I want to add a UPS/battery with charger to my wifi adsl router to keep it running during load shedding (say 2.5 hours) and would appreciate any advice. I have read the whole thread and it seems some people are managing this with a 650 UPS. Other threads on this forum say that since the router is 12v that the best solution would be a good battery with a charger. What would be best? I am willing to spend up to R1200 but less would of course be better. The solution needs to be neat since the router is in the family room - which is making me lean towards a UPS - but from what I have read here it seems that UPS devices are not designed to last for 2.5 hours even under a small load. If possible I would like to connect a light (possible LED) to the same UPS/battery.

Go to a security shop that sells CCTV cameras and such. Buy a Powermax Powerpack, which is a 12V DC UPS, along with the 7 Ah battery that fits inside. The max drain from the router should be 1 A, so you can run it for 3+ hours without damaging the battery. Or get a lead crystal 7 Ah battery, which you can drain to 0% without damage for longer running time or extra LED lights.

This is more efficient than a standard UPS (although the standard one will also work). I have one of these for my ADSL router, although I hooked up an old 45 Ah battery (old UPS battery from work). System works very well, and the router is protected from surges and dips. The one thing to keep in mind is the phone cable protection which goes through the normal power adapter. You can leave that plugged into a socket just to protect the phone line , and run the power from the UPS. Or if you use a normal UPS it will be the same as normal.

Edit: Some exchanges have their own backup power, ours is on through all the load shedding. Maybe just check if your phone stays on before buying anything.

 

[verge]

Thank you for the input

Go to a security shop that sells CCTV cameras and such. Buy a Powermax Powerpack, which is a 12V DC UPS, along with the 7 Ah battery that fits inside. The max drain from the router should be 1 A, so you can run it for 3+ hours without damaging the battery. Or get a lead crystal 7 Ah battery, which you can drain to 0% without damage for longer running time or extra LED lights.

Edit: Some exchanges have their own backup power, ours is on through all the load shedding. Maybe just check if your phone stays on before buying anything.

I am going to go with this option and will give feedback on this thread. One last thing - if my phone stays on during load shedding does it necessarily mean that my ADSL connection will also stay on?

 

[furpile]

I am going to go with this option and will give feedback on this thread. One last thing - if my phone stays on during load shedding does it necessarily mean that my ADSL connection will also stay on?

I don't have a landline so I can't say for sure, but I think so. Someone mentioned to me that during loadshedding their phone and ADSL goes down (different area than where I live). So if the exchange can accept phone calls it should run ADSL as well.

 

[Dan C]

I am going to go with this option and will give feedback on this thread. One last thing - if my phone stays on during load shedding does it necessarily mean that my ADSL connection will also stay on?

Depends on your DSLAM. Mine goes down after +-15min everytime.

 

[furpile]

Depends on your DSLAM. Mine goes down after +-15min everytime.

But is your phone working after ADSL goes down?

 

[verge]

Do I need to unplug?

Go to a security shop that sells CCTV cameras and such. Buy a Powermax Powerpack, which is a 12V DC UPS, along with the 7 Ah battery that fits inside. The max drain from the router should be 1 A, so you can run it for 3+ hours without damaging the battery. Or get a lead crystal 7 Ah battery, which you can drain to 0% without damage for longer running time or extra LED lights.

This is more efficient than a standard UPS (although the standard one will also work). I have one of these for my ADSL router, although I hooked up an old 45 Ah battery (old UPS battery from work). System works very well, and the router is protected from surges and dips. The one thing to keep in mind is the phone cable protection which goes through the normal power adapter. You can leave that plugged into a socket just to protect the phone line , and run the power from the UPS. Or if you use a normal UPS it will be the same as normal.

Edit: Some exchanges have their own backup power, ours is on through all the load shedding. Maybe just check if your phone stays on before buying anything.

One more thing - well actually three

First - I cannot find a diagram showing how this will work. Will the Powermax be plugged in to the wall - and the router then in to the powermax - like with a UPS? I am not sure because the router's transformer expects 220v?

Second - is the metal poles on this battery correct: http://www.bushpower.co.za/products.asp?pid=545 - I am not sure is clamps are used or what kind of connector between the Powermax and the battery.

Third - I have not been able to source the Powermax in Cape Town - and tips?

I greatly appreciate the advice.

 

[Tinuva]

That link is to Communica. There is a Communica branch in Woodstock (cape town), pretty much at the Lower church offramp from the N1.

Saying this, not knowing whether you phoned and asked Communica Woodstock whether they have stock or not.

 

[furpile]

One more thing - well actually three

First - I cannot find a diagram showing how this will work. Will the Powermax be plugged in to the wall - and the router then in to the powermax - like with a UPS? I am not sure because the router's transformer expects 220v?

Second - is the metal poles on this battery correct: http://www.bushpower.co.za/products.asp?pid=545 - I am not sure is clamps are used or what kind of connector between the Powermax and the battery.

Third - I have not been able to source the Powermax in Cape Town - and tips?

I greatly appreciate the advice.

Sorry, this method requires a bit of DIY and electronics knowledge. You will need an old modem power cable that you can cut the plug off off (or buy a new one from an electronics store). The powermax unit plugs into a wall socket with a normal 3 pin plug. Inside the box is space for the battery you linked (standard 12V 7 Ah) with the matching connectors. So you just open the unit and plug in the battery. Then you need to attached a cable with the round pin required by the modem (I cut off the cord from an old wifi router). Just check the polarity of the modem's power supply before attaching the cable to the powermax unit (inside and outside of the round plug). So basically the powermax unit replaces your modem's power supply.

If you don't feel like doing DIY, it will be easier to go the standard UPS route (you will still need to make a connecting cable between UPS output (kettle plug) and a standard multiplug).

This seems to do the same thing.

 

[verge]

Sorry, this method requires a bit of DIY and electronics knowledge. You will need an old modem power cable that you can cut the plug off off (or buy a new one from an electronics store). The powermax unit plugs into a wall socket with a normal 3 pin plug. Inside the box is space for the battery you linked (standard 12V 7 Ah) with the matching connectors. So you just open the unit and plug in the battery. Then you need to attached a cable with the round pin required by the modem (I cut off the cord from an old wifi router). Just check the polarity of the modem's power supply before attaching the cable to the powermax unit (inside and outside of the round plug). So basically the powermax unit replaces your modem's power supply.

If you don't feel like doing DIY, it will be easier to go the standard UPS route (you will still need to make a connecting cable between UPS output (kettle plug) and a standard multiplug).

This seems to do the same thing.

I feel like doing DIY - I think what I will have in the end will be better than a UPS that will last longer - and from what I can see now we are going to have the Eskom problem still for a number of years. I want something that will last - is not too ugly and not that expensive.

I now understand what you mean i.e. I will not be using my router's existing transformer anymore.

Do the volts and amps have to be the same? I see on the sticker of my router's existing transformer that the output is 12V and 2A. The product in the link you sent is 13.6 VDC and 3A - I guess you are saying the 13.6VDC and 3A is the maximum and the router will only use 12V and 2A?

 

[itareanlnotani]

My 750va from makro use to do the full 2.5 hours.

2 months later it is only good enough for 50 min.

Lead Acid doesn't like being discharged. Figure on about 30%-50% actual usable capacity if you want any sort of lifetime.

UPS's also usually completely $#%^@#$ lie about the actual capacity.
I figure you probably have a 12v/7.5Ah battery in there.

12v * 7.5Ah = 90Whr capacity, or 30-45Whr usable depending how long you want it to last @ 30% DoD.

 

[furpile]

I feel like doing DIY - I think what I will have in the end will be better than a UPS that will last longer - and from what I can see now we are going to have the Eskom problem still for a number of years. I want something that will last - is not too ugly and not that expensive.

I now understand what you mean i.e. I will not be using my router's existing transformer anymore.

Do the volts and amps have to be the same? I see on the sticker of my router's existing transformer that the output is 12V and 2A. The product in the link you sent is 13.6 VDC and 3A - I guess you are saying the 13.6VDC and 3A is the maximum and the router will only use 12V and 2A?

Rather check under your modem what it requires, should be max 1,5A. The power supply is normally a bit larger, but the modem will only draw the amount of current it needs if the voltage is correct. The spec of the powermax unit includes the battery charger, which requires more than 12 V.

 

[itareanlnotani]

I feel like doing DIY - I think what I will have in the end will be better than a UPS that will last longer - and from what I can see now we are going to have the Eskom problem still for a number of years. I want something that will last - is not too ugly and not that expensive.

I now understand what you mean i.e. I will not be using my router's existing transformer anymore.

Do the volts and amps have to be the same? I see on the sticker of my router's existing transformer that the output is 12V and 2A. The product in the link you sent is 13.6 VDC and 3A - I guess you are saying the 13.6VDC and 3A is the maximum and the router will only use 12V and 2A?

V * A = W

12V @ 2A = 24Watt draw per hour.

(assuming power factor of 1 here, for simplicity)

If you want to run it for 3-4 hours, you need...

24W per hour x 3 = 72W capacity.

Lead Acid can reasonably only be used for 30-50% discharge, so multiply by 3 to get battery capacity actually required.

72W * 3 = 216W hr required.

216W hr / 12V = 18Ah battery size required for 3 hrs runtime.

So you'd need a 12v / 18Ah battery. Or if your UPS charges at 24V, then you'd need 2 x 12v / 9Ah (as 24V is 2 x 12v wired in series).


Its fairly simple stuff.

 

[furpile]

V * A = W

12V @ 2A = 24Watt draw per hour.

(assuming power factor of 1 here, for simplicity)

If you want to run it for 3-4 hours, you need...

24W per hour x 3 = 72W capacity.

Lead Acid can reasonably only be used for 30-50% discharge, so multiply by 3 to get battery capacity actually required.

72W * 3 = 216W hr required.

216W hr / 12V = 18Ah battery size required for 3 hrs runtime.

So you'd need a 12v / 18Ah battery. Or if your UPS charges at 24V, then you'd need 2 x 12v / 9Ah (as 24V is 2 x 12v wired in series).


Its fairly simple stuff.

You get 7Ah lead crystal batteries now as well which can be drained to 0% without damage (supposedly). Since the output is 12V and the router uses 1A max (normally, not the 2A the power supply can give) you have 7 hours of use if you drain it 100%, and about 3,5 hours for 50% with normal batteries. Thus it's enough for most load shedding durations.

 

[verge]

Rather check under your modem what it requires, should be max 1,5A. The power supply is normally a bit larger, but the modem will only draw the amount of current it needs if the voltage is correct. The spec of the powermax unit includes the battery charger, which requires more than 12 V.

I have checked under the modem - Power input: 12 - 15V and 1.2 - 0.9A. (Further it also states - Power Consumption: 13.5W (MAX)

Now that I know there is a Communica branch in Woodstock I can buy the Powermax unit (thank you Tinuva). Thank you Isheed for the simple calculation. I am going to get a lead crystal battery.

Can anyone please confirm that I do not need to worry that the Amps produced by the Powermax is higher than what the modem can take.

I am also considering adding a 12V LED light - what A do they typically use - would this mean that I should get a larger battery?