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Replacing a 120v 3000VA UPS

Pancakes

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Sep 24, 2021
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Hello all,

Big fan of the channel and the forum. I have a UPS which powers a lot of critical items in my home, an APC SRT3000RMXLA which is a 120v, 3000VA, 2700w double conversion UPS.

It may, or may not have just given up the ghost. I ordered a new battery pack ~$300 and we will see if that solves the problem. But either way, I'm looking for a way to convert it to LiFePO4, or replace it entirely

If the UPS is dead, a used replacement is at least $1300 so that's the starting budget, however I will spend more if needed. The catch is that it MUST be double conversion, I have some devices that for whatever reason do not play well with line interactive UPS's, and I just want it to be double conversion, also.

Can anyone suggest hardware? If its rackmount, all the better. As this lives in a rack currently

I'm looking for a similar or larger capacity, and battery runtime needs to be at most 10 mins. I have a standby generator which takes 10 seconds to power on and switch, but in the event the power failed and the generator was inoperable, I'd need a few minsto wheel out my portable generator

Has anyone embarked on this journey before? Size is not a concern for me at all

My main reason for going down this path is that I'm just having worse and worse luck with lead acid. New Interstate car batteries only last 2-3 years in my vehicles, and I'm getting 2-3 years out of UPS batteries now too. In the past I could get 6-7, seems like quality is down
 
For double conversion UPS, Chargeverter to charge batteries (easily takes dirty generator power) and something like a 3kW off grid Growatt to provide AC power.

If you want the best equipment, then Victron charger and inverter.

Chargeverter is 48v. Charger and inverter is about $800. 5kw battery would run for 1+ hours, but cost you. You don't want to drain a lifepo4 battery in less than 1 hour.
 
Thanks!

So I could get a single EG4 LifePower4, together with a charger and inverter and call it a day? Also a bonus that all my loads are 120v, but then I assume I could easily make the charger 240v to better balance the load
 
Very interesting, I personally don't mind if it has a fan

I assume something like this which is the inverter and charger cannot be configured to be double conversion?

 
Very interesting, I personally don't mind if it has a fan

I assume something like this which is the inverter and charger cannot be configured to be double conversion?

Inverter chargers are bidirectional so they can not do double conversion. They are either charging or inverting. They can often do pass through with varying reaction times on input loss.
 
Got it, so a pass for sure. I guess if I happened to find a good deal on one though, I could just not use the charger functionality?

Maybe I'm missing them, but it seems Victron don't make just an inverter that also isn't a charger?
 
Thanks!

So I could get a single EG4 LifePower4, together with a charger and inverter and call it a day? Also a bonus that all my loads are 120v, but then I assume I could easily make the charger 240v to better balance the load
Wire the CV for 240v. It is half the output at 120v.
If you only have 120v load, then you can get a 120v inverter. If you get a 240v inverter, you should balance the loads on each line.
 
240 in and 120 out is really ideal for me too, sounds like a win-win! I can't balance the loads between each leg if I get a 240v inverter, as most or all loads will on a 120v 30a ATS PDU

I think the Chargeverter is a winner. Unless someone says otherwise, I think the EG4 LifePower4 battery is a winner too. Just looking for the right inverter now
 
Just looking for the right inverter now
 
I've had this along with a 12v 200AH plus Litime battery running for about 6 months to replace a failed SU2200 - it has a UPS function with 5ms switchover time - the sever never complains or reboots when it switches over and back. You can configure it to run are straight from wall power and just keep the battery topped up, or run from battery and cycle it to 40% then run from AC until it is charged.

On the SU2200 I got 45 minutes runtime, on this I get around 4 hours runtime. The only real downside is the lack of notification to the computer of battery exhaust - but there are a number of RPi projects to provide that.

Expertpower makes units up to 5kW in various voltages.

I started out where you are not wanting to spend another $200 on batteries that would have failed in 2 years. And I used the same price rational. Of course after I bought my stuff I looked on ebay and used UPS without batteries are cheap cheap cheap
 
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