question

I may be misunderstanding your situation, but if you are looking to replicate the Yeti by using a 24V 100AH battery, you’ll need an inverter to make 230AC from the battery, and a charger to recharge the battery from an AC source such as a generator or line (shore) power. Take a look at an inverter/charger like the Multiplus 500 or 800 VA models. They should cover your needs (along with the battery, and of course whatever cabling, outlets, etc you will need). The advantage is that the unit can be a short distance from your listening area, so any mechanical noises are muted.

Considering cost, a all-in-one battery backup might be worth considering, as well. The LiFeP04 battery you’re considering will be over $1000 alone, before the inverter/charger and other wiring costs.

On the other hand, building and learning how these systems work is fascinating. I am sure I spent more on mine than a pre-made unit would cost, but I know what it is made from and can have confidence it will last. Perhaps that is your feeling too.

Working with a good Victron dealer will be a big help to you!

A couple of points... That will likely apply to both packaged and componant systems.

Most, including Victron, inverter chargers use the same bridge to charge and discharge the battery. A UPS is therfore likely to directly connect your load to your supply when the supply is available.

If you take a Multyplus as a case in point you can considder it like a 'T' connection with the AC feed on the left the AC load on the right and the inverter/charger linking the battery on the vertical leg.

It will either take AC from th supply and feed the load whilst also charging the battery or disconnect the AC feed, with a relay, and supply the load from the battery.

There are caviats... It can assist the AC supply, feeding the load from both AC supply and battery and can even export to the AC supply but neither of these scinarios are relavent to you and even if they were the inverter would be using the AC waveform as a template and matching it.

It sounds like you want a clean AC supply that is always being inverted from a DC supply.

In that case you would want a seperate charger and inverter... Take AC and make DC, with apropriate charge control to protect your battery.
Sepertly take DC from the battery and produce a clean AC supply that is isolated from the Grid/AC supply.

In the latter case you probably dont need a big battery, just big enough to act as a buffer. Have a look at 'Online UPS' these systems generally work this way and only use a transfer switch, connecting AC supply to AC load in the event of an inverter/battery fault, and or optionnally.

Additionally, at a few hundred Watts you could easily use a 12V system which will cap the battery costs and as you dont need to cycle the battery or only partally charge it with solar you could pick a lead based battery further reducing cost.

Lastly... If you always have AC grid available there are packaged clean AC supplies available that work as above, always inverting, but dispence with the battery entirly and use a capacitor based DC link between the DC supply and the AC inverter. In fact any isolated AC switch mode power supply will be working this way.

In all cases the fans will run when the inverter/charger or both are hot, at the very least. Check th specs and or talk to the manufacturer to determine the maximum output that is supported with passive cooling.
This may not be easy to get a definitive answer about as it will generally depend on ambiant temperature if it isnt directly linked to load.

Al