Buying 2 RCT UPS Units

[DrewChan]

Could you plug them into each other?

IE One unit powers your TV during load shedding, the other unit chargers the one powering the TV - efficiency isn't perfect so I guess you'd get around 1.7 times the normal UPS uptime.

I suck at modifying electronics, so this seems like an easy solution

 

[henry1103]

No

 

[TehStranger]

Could you plug them into each other?

IE One unit powers your TV during load shedding, the other unit chargers the one powering the TV - efficiency isn't perfect so I guess you'd get around 1.7 times the normal UPS uptime.

I suck at modifying electronics, so this seems like an easy solution

Before you try this I'd have a read through the various UPS/Inverter threads on here and understand how the systems work.

Then figured out your load (i.e. the things you want to power, TV, lights, DSTV decoder etc.), say 400w.

After this find a UPS/inverter that is rated to handle the load (i.e. a 600w, 12v Ellies inverter). Bonus points if the inverter has a built in charger (in fact I wouldn't look at one without built in charger).

Then decide how long you want to keep the load on for (i.e. 2.5 hours) and work out the capacity of batteries you need (rated in Ah). You do this with the following:

• Load (say 400w) / inverter efficiency (0.8, or 80% for a modified sinewave inverter) = Actual load (500w)
• Actual load (500w) / Inverter voltage (12v in this case, can be 24v, 48v etc.) = You Ah requirement i.e. how many Amps you need to run the load for one hour (41.67Ah).
• 41.67Ah x 2.5 hours (your time requirement) = The capacity of battery you require (104.167Ah), however this assumes 100% Depth of Discharge (DoD) which will damage the batteries and dramatically reduce their lifespan (measured in cycles).
• 104.167Ah x 2 (because you only want to discharge to 50%, hence you need to double your available battery capacity) = 208.33Ah

To get this 208.33Ah capacity you can simply buy 2 x 12V 105Ah batteries and connect them to a 12V inverter in parallel (not series).

Now that you've got some terms and a brief explanation I'd suggest Googling and/or reading through the threads on here again.

Otherwise share your requirements here and we can suggest a tailored setup for you.

 

[henry1103]

Plugging 2 modified sine wave UPS devices to each is usually a bad thing because these waves cause disturbances and will most likely damage your electronics.

I'm assuming you'll need some sort of wave regulator to sync the two waves and connect the 2 UPS to this regulator, then using this to power your TV.

 

[DrewChan]

Before you try this I'd have a read through the vari

Done all this already, know what I need, have the excel calculator... I literally know 75% of the theory. It's the putting it all together I am unfamiliar with.

IE- If I have inverter/ Deep cycle battery, actually setting them up in parallel/ connecting to inverter - I am likely to kill myself (Also I am colourblind) hence never working with electric cabling

 

[TehStranger]

Done all this already, know what I need, have the excel calculator... I literally know 75% of the theory. It's the putting it all together I am unfamiliar with.

IE- If I have inverter/ Deep cycle battery, actually setting them up in parallel/ connecting to inverter - I am likely to kill myself (Also I am colourblind) hence never working with electric cabling

That's why the batteries come with +/- next to the terminals, no colour vision required.

For your reference:



Edit - I'm sure a CT member can pop around and help you set up?

 

[Joker]

Nice write-up TehStranger, any suggestions on what would I need to run a 1000W PSU/PC + 24" LCD monitor for 2.5hrs?

 

[TehStranger]

Nice write-up TehStranger, any suggestions on what would I need to run a 1000W PSU/PC + 24" LCD monitor for 2.5hrs?

It depends on your actual power draw from the PC. While the PSU can supply 1000w, it probably won't do this unless you have a monster PC at 100% load (and gaming doesn't come close to 100% load). Plus remember that your PSU has it's own efficiency losses, so if it's supplying 500w at 85% efficiency, the actual draw at the wall would be around 588w.

You can buy basic wall meters from retailers like game for around R350 (can't find the link now unfortunately) that will plug in between the wall socket and your multiplug.

I'd suggest an inverter like this, with two or three of these batteries, depending on your actual load.

Otherwise you can buy an all in one unit like this at a slight premium (Makro used to sell these for R7,200). My SO's family has the same unit powering their TV/lounge setup which has done service over the last 4 years without a hitch.

Edit: I've linked modified sine wave inverters which are cheaper than pure sine wave inverters, but may be slightly worse for your equipment. My SO's family's lounge setup hasn't had any issues on a modified sine wave inverter for 4 years, so I'm not too worried about modified sine waves. My home setup also uses a modified sine wave inverter too for what it's worth.

 

[Joker]

Great thanks so much - looking into those options for sure.

 

[midnightcaller]

Before you try this I'd have a read through the various UPS/Inverter threads on here and understand how the systems work.

Then figured out your load (i.e. the things you want to power, TV, lights, DSTV decoder etc.), say 400w.

After this find a UPS/inverter that is rated to handle the load (i.e. a 600w, 12v Ellies inverter). Bonus points if the inverter has a built in charger (in fact I wouldn't look at one without built in charger).

Then decide how long you want to keep the load on for (i.e. 2.5 hours) and work out the capacity of batteries you need (rated in Ah). You do this with the following:

• Load (say 400w) / inverter efficiency (0.8, or 80% for a modified sinewave inverter) = Actual load (500w)
• Actual load (500w) / Inverter voltage (12v in this case, can be 24v, 48v etc.) = You Ah requirement i.e. how many Amps you need to run the load for one hour (41.67Ah).
• 41.67Ah x 2.5 hours (your time requirement) = The capacity of battery you require (104.167Ah), however this assumes 100% Depth of Discharge (DoD) which will damage the batteries and dramatically reduce their lifespan (measured in cycles).
• 104.167Ah x 2 (because you only want to discharge to 50%, hence you need to double your available battery capacity) = 208.33Ah

To get this 208.33Ah capacity you can simply buy 2 x 12V 105Ah batteries and connect them to a 12V inverter in parallel (not series).

Now that you've got some terms and a brief explanation I'd suggest Googling and/or reading through the threads on here again.

Otherwise share your requirements here and we can suggest a tailored setup for you.

Thanks for this very simple explanation.