Load shedding power backup solutions

Grand Guru

Grand Guru

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I’m seeking advice. I need a cost effective system to power my Wi-Fi router, TV and android box during load shedding. I made some research on YouTube and found many videos but it’s getting a bit confusing. Which route should I take. Inverter or UPS? With or without additional batteries. Lead acid, marine deep cycle or Lithium? I’m honestly completely lost.
 
If you're after an off the shelf solution, something like this would do the job.
Most home routers / router-transponders are 12 Volt and draw some 500 to 800mA, (check the label on your device), so using a product like this would in theory, (and at worst case), give you 7.2A/Hr divided by 800mA = 9Hours, buuuuuuuuuut ... One should NEVER discharge a lead acid battery below 50%, so your safe limit would be 40% of 9Hours = 3.6 Hours of backup.
It would typically require roughly double the discharge time to recharge a sealed lead acid battery, and as we typically have a little over 2 hour sheds with 5+ hours on time ... you'd be be well within spec,
If you're technically, (electrically), proficient, you could make up something similar for about a third of the price, to which I'll gladly provide a schematic if there's interest.

Also;
Just so there are no "surprises" down the line ... Most sealed lead acid batteries are only good for some 400 charge / discharge cycles, and based on our current shedding of three times a day ... you'd get 400/3 = 133 days, (4.4 Months of use) ... so be prepared to replace the battery every 6 months to a year dependant on what the Eishkom munchkins graciously offer us :rolleyes:
 
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Intuthu Kagesi said:
If you're after an off the shelf solution, something like this would do the job.
Most home routers / router-transponders are 12 Volt and draw some 500 to 800mA, (check the label on your device), so using a product like this would in theory, (and at worst case), give you 7.2A/Hr divided by 800mA = 9Hours, buuuuuuuuuut ... One should NEVER discharge a lead acid battery below 50%, so your safe limit would be 40% of 9Hours = 3.6 Hours of backup.
It would typically require roughly double the discharge time to recharge a sealed lead acid battery, and as we typically have a little over 2 hour sheds with 5+ hours on time ... you'd be be well within spec,
If you're technically, (electrically), proficient, you could make up something similar for about a third of the price, to which I'll gladly provide a schematic if there's interest.

Also;
Just so there are no "surprises" down the line ... Most sealed lead acid batteries are only good for some 400 charge / discharge cycles, and based on our current shedding of three times a day ... you'd get 400/3 = 133 days, (4.4 Months of use) ... so be prepared to replace the battery every 6 months to a year dependant on what the Eishkom munchkins graciously offer us :rolleyes:
Click to expand...
Will that suffice to run router, 40 inch TV ser and an android box?
 
Grand Guru said:
Will that suffice to run router, 40 inch TV ser and an android box?
Click to expand...
Probably not the 40" TV set but quite possibly yes to the android box, altho' I'd like to check the manufacturers label before committing to a yes.
Take a pic of the manufacturers labels on both your android box and TV and send it / PM me / post it here, and I'd be able to answer that for you ...

My TV only has a 240Volt input and is rated at 120Watts, so that 12Volt backup I mentioned in my previous post wouldn't suffice ... My TV would require a modified sine or sine wave inverter rated at at least 120Watts, but preferably with some headroom ... say 200 Watts, with battery(ies), capable of supporting the time frame required, (3 hours?) ... remembering to calculate your required battery Ah rating as DOUBLE that of what your TV requires.

My Android Box has a PSU rated at 5V at @Amps, (altho' it draws around 700mA), to which an off the shelf USB Power Bank would do the job, to which most power banks have a "feed through" option, meaning you could leave it permanently attached to both your android box and it's charger.
 
My set up is 4 x 3.2 V Lithium packs in series to make a 12 V battery with a BMS. You can get a 12 V Lithium battery with built in BMS

You need a charger that can charge AGM batteries or a lithium charger or bench charger.

Then you need an inverter, mine is a 350w

I run a 50" Led tv, a Mi box and router for max 5 hours ........ or my camping fridge

I would not go lead acid for this type of application
 
Battery

Normal lead acid: Typically this type of battery only uses the top 20% as they are designed for cranking. This means a short high amp discharge, such as starting your car, and then a quick recharge via a high amp input such as from your car alternator.

High cycle: Similar to a crank battery but the internals have thicker plates that enable the battery to be used as a crank battery and also as a power source for auxiliaries. For example camping fridges, caravans 12 V systems and RV's. Usually you can discharge down to 50% without damage

Deep cycle: these batteries are not designed to crank. They are designed to allow flow over a much longer period of time. An example would be a trolling motor on a boat.

Lithium: different kettle of fish altogether. Lithium works best for solar applications as the chemistry allows for a slow and flat discharge curve. They do not like sudden discharges but will charge up very quickly to around 90 %. You can use approximately 80% of the battery without damage.

So if you take one x 200 amp deep cycle lead acid battery, you can effectively use around 100 amps of that battery. That battery weighs around 40kg. One x Lithium 120 amp battery will give you 96 amps usable and weighs around 10 kgs.

The deep cycle will take days to recover on a charger, the Lithium will take hours.
 
So if I understand well I may keep the Wi-Fi up and running for less than R1k but if I want the Tav and the android box with, I’ll have to invest a lot more money?
@Intuthu Kagesi I have an Nvidia Shield Pro 2019 version (I have no idea about the power requirements) and a Samsung smart tv that says 100W
 
Grand Guru said:
So if I understand well I may keep the Wi-Fi up and running for less than R1k but if I want the Tav and the android box with, I’ll have to invest a lot more money?
@Intuthu Kagesi I have an Nvidia Shield Pro 2019 version (I have no idea about the power requirements) and a Samsung smart tv that says 100W
Click to expand...
Correct!
What I proposed earlier will work perfectly for your internet connectivity, and; A quick Google search reveals that your Nvidia Shield Pro 2019 has a USB-C connector and draws 10W, (2000mA @ 5Volts), so any decent Power Bank of say 10000mAhr in series / in feed through mode with your existing PSU would more than suffice for it's requirements, giving you some 5 Hours of backup ... I would however suggest an upgrade to a 3 Amp USB-C PSU from it's existing 2.1Amp one, to improve the recharge time whilst in feed through mode.

Your Samsung TV however requires 100Watts of 220-240VAC. The good news is that it has a switched mode PSU internally, so you you don't necessarily require a sine wave UPS, meaning you could use a much cheaper stepped sine or even a square wave UPS for it, so ... Catering for a 25% switch on surge ... you would then require a 125 - 150Watt square wave or stepped square or even a sine wave UPS and or inverter, to which you'd need to adjust your battery capacity to suit the backup time you require of some 2 to 3 hours.

What is proposed by others above with respect to larger UPS's could well encompass everything and more, however you specifically asked for internet connectivity, and then added your TV, so I'm assuming your lighting, fridge(s), stove? aren't a priority.
 
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Adephi said:
I'm sure these are too small for what you need. But then again, I know as much about electricity as an Eskom engineer,

mybroadband.co.za

Keep your router on during load-shedding with these cheap backup batteries

For as little as R595, South Africans can get a small uninterruptible power supply (UPS) to provide backup power to their wireless Internet connection during load-shedding.
mybroadband.co.za mybroadband.co.za
Click to expand...
Banking on 12V @ 1Amp , (12Watt/hr), and based on our average shed of some 2 to 3 hours ... they're a great inexpensive backup option for a router / combo router wireless transponder :campeon:
 
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