Hi,

Looking to add a simple UPS system to my house for now with Li batteries for load shedding charging from the grid. Currently have a system with a  old Solarwize 24v inverter (10 years).

It still works fine but it chows through lead acid batteries and I wanted a setup that I could expand in the future and would be reliable.

These two stood out, if there’s a better option, give a shout. Our max load currently is about 1200W with computers and lights and TV (usually more around 7-800) but I’d like to start adding to it as well. Like a fridge and and AC or two.

The sunsynk is around 20k and the Victron around 15k. Which was odd because I’d read everywhere that Victrons were more expensive. Maybe the Victron needs extra pieces? I read that in some places but didn’t see that in the manual for just a grid connection.

Also wanted to ask what switching from a 24V system to a 48V system would entail. Almost everything seems to be at that voltage in the market. Although there are some decent lower wattage 24V systems.

i was considering for a bit just using a drop in Lithium battery in my current system but it felt like it’d be a waste if a battery and that money would better go to saving for a better system.

Thanks! 
Sorry for the ramble.

Edited February 5, 20242 yr by MuneebK
Formatting

The Victron will need a seperate MPPT AFAIK when you want to add solar.  The Sunsynk has MPPT built in. Pro's and Cons to both.

48v vs 24v - I'll take a stab at it - thinner cables required due to higher voltage and less amps for the same watts through the cable. Almost all 5Kwh or bigger LiFePO4 batteries on the market are 48v/51.2v now so your inverter would have to support that. I wouln't go for a battery smaller than 5Kwh.

 

Cheers

Douw

 

 would go 48v from the start it just allows more growth in the future. If you going to build your system over time then the Victron is a great system but more expensive. If you going PV panels and battery right from the start, then the hybrid inverter is great.

18 hours ago, Douw G. Gerber said:

The Victron will need a seperate MPPT AFAIK when you want to add solar.  The Sunsynk has MPPT built in. Pro's and Cons to both.

48v vs 24v - I'll take a stab at it - thinner cables required due to higher voltage and less amps for the same watts through the cable. Almost all 5Kwh or bigger LiFePO4 batteries on the market are 48v/51.2v now so your inverter would have to support that. I wouln't go for a battery smaller than 5Kwh.

 

Cheers

Douw

 

So shouldn’t be any hassle to upgrade since the thick cables are already in, right?

 

Thanks!

4 hours ago, Greglsh said:

 would go 48v from the start it just allows more growth in the future. If you going to build your system over time then the Victron is a great system but more expensive. If you going PV panels and battery right from the start, then the hybrid inverter is great.

Yeah that was the thought. Weirdly in this case out of the two I listed the Victron is 5k cheaper.

18 minutes ago, MuneebK said:

Yeah that was the thought. Weirdly in this case out of the two I listed the Victron is 5k cheaper.

If you search around, news is that Victron is being accused of resale price maintenance, basically keeping the selling price high. Maybe the price you're seeing now is more reflective of the free market.

I would advise you get a quote from reputable installers who will ensure that all components are considered, including safety breakers/fuses, installation costs, any DB work that may be required so it's sorted to future proof yourself. With inflation, prices will always be going up. A discussion with installers will also include what the other components you will want to add so the system then costs you less when you are adding up those things. Panels obviously at some point will be a consideration and all the pros and cons will be given so you can compare like for like or almost anyway. If you ever decide to add power tools or induction cooktop, these can be discussed. The reason Victron is said to be expensive is additional components that are outside/not part of the inverter.

I've also found that once you begin going bigger it's also tempting to add items to a system so the return on investment is worthwhile, maybe you'll add a microwave or a washing machine etc...

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Also wanted to ask what switching from a 24V system to a 48V system would entail. Almost everything seems to be at that voltage in the market. Although there are some decent lower wattage 24V systems.

If you are looking at installing a new system I would definitely go with 48V. It is the market standard at the moment.

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The sunsynk is around 20k and the Victron around 15k. Which was odd because I’d read everywhere that Victrons were more expensive. Maybe the Victron needs extra pieces? I read that in some places but didn’t see that in the manual for just a grid connection.

I would say that Victron is the slightly better product - and can handle large surges better than Sunsynk can. In car terms I would equate Victron to the Mercedes Wagon and Sunsynk to a Lexus. That said, there are definitely a lot more installers that are familiar with Sunsynk. The Sunsynk app is a big selling point and Victron hasn't replicated that functionality "out-of-the-box". But it is easier to connect Victron to the likes of Home Assistant. That said, the gap is closing with the work done by a couple people on this, including https://github.com/kellerza/sunsynk and https://smarthomeintegrations.co.za/product/smartdeyedonglev4/

The Victron system is a modular system and needs a few more parts. The MPPT and Venus device have to be bought separately. This will push up the price - to be higher than Sunsynk. For just battery backup, I still think you need the Venus. The Victron is more quiet than the Sunsynk and doesn't require the same clearances. This is because the design. The Victron is only IP20 rated with open fans. The IP65 rating of the Sunsynk means there is no internal airflow.

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These two stood out, if there’s a better option, give a shout. Our max load currently is about 1200W with computers and lights and TV (usually more around 7-800) but I’d like to start adding to it as well. Like a fridge and and AC or two.

I currently have a 5kw Victron inverter and can run all my lights, PC's, two fridges as well as the kettle and microwave. I try not run the kettle and microwave at the same time but the inverter handles it for extended periods. My normal base load is a bit lower though at about 350W - until a fridge kicks in. Other than my stove and geyser - everything is powered by the inverter.

You may need to be careful with the aircon - older models can kick a bit and will be heavy on the battery.

I love my Victron, it has served me well. But I would have to give Sunsynk a serious consideration if I repeated the exercise. The new 5.3kw Powerlynk XL combined battery/inverter unit is about to land. The pricing looks like it will be really good and make for a nice install. https://www.sunsynkmobile.com/the-powerlynk The 3.6KW version is priced at R34k.

Your power consumption looks a little high - maybe check your bulbs that you are running. Nothing like a few 50W downlights to up your consumption. To run 800w average for 4 hours you 3.2kwh which equates to 4kww of lithium battery - assuming 80% DOD. To replace your current your current batteries you would need to get about 4 batteries at R6k a pop. Your spending R24k. That's a little less than the cost of a Sunsynk battery.

To size you system I would look at some type of a watt meter, Fluke clamp or current meter. It will give you a real idea of what some devices can use - and plan your system appropriately.

I would really consider solar panels. With the current Eskom prices - and how lithium batteries can be cycled - you  can really start saving money. Sunsynk and Victron can supply non-essential loads. Your solar can help power your geyser & everything.