Where to source a UPS and inverter 12/230v ?

Tuttlinghorn

not 100% sure where on boards this question might get answered so … 

does anyone have a source for a UPS ( uninterruptible power supply ) that’s designed to work with an external ( 12v ) battery ? 

something like this https://darel.lv/en/home-equipment/6746-inverter-with-ups-for-heating-system-600w-lcd-adler-co-sinusups-600w-lcd.html or https://www.amazon.de/-/en/PROsinus-500-URZ3405B-Inverter-Charging-Function/dp/B076J2LZ65

I’m trying to help some friends in Ukraine to cope with extreme power outages. They’re in an apartment, so a generator isn’t an option. Main requirement is to power a gas water heater / pump .

Everything I can find on the web is out of stock or is a UPS designed for office usage & with built in battery. I can also find an inverter which will take a 12v battery but not what I’m looking for.

Due to the level of demand, most / all suppliers in-country and bordering countries are out of stock

all ideas on potential suppliers would be appreciated !

2011

I'm thinking cheap and readily available, so avoiding a stardard UPS. Something like this would work:

https://www.fruugo.ie/4000w-12v-220v110v-led-ac-car-power-inverter-converter-charger-adapter-inversor-dual-usb-transformer/p-99935846-209973731?language=en&ac=croud&asc=pmax&gclid=CjwKCAiAp7GcBhA0EiwA9U0mto8-jCseYEqw3SrCPjbBhv5yfgH3q6nlk35CSW1d9Ezm5wDHypoX2hoC8SgQAvD_BwE

Just add 12V batteries. The batteries can be charged when power is available. Several of these inverters could connect to the same bank of batteries.

What sort of loads are planned? Anything with a heating element is best avoided.

10-10-20

If per-chance it's for charging small DC devices, avoid going the DC->AC->DC conversion route. Some of the highest efficiency conversions can be done with simple but good quality 12v cigarette chargers such as this:

https://www.amazon.de/UGREEN-Charger-Cigarette-Lighter-Compatible/dp/B0B4NLRRH5/ref%3Dsr_1_2_sspa

Just link them off the 12v battery via one of these:

https://www.amazon.de/cigarette-lighter-extension-alligator-vehicles/dp/B09GLZ7178/ref%3Dsr_1_26_sspa

2011

Or here is another good option that also has a USB type A output:

https://www.screwfix.ie/p/maypole-1000w-12v-to-230v-power-inverter-type-a-usb-charger/113FY?gclid=CjwKCAiAp7GcBhA0EiwA9U0mtuFwsiZJOrTjeODCYR1KSzH7b_9F9LZkG5bKFPh5l34d4c7RC77tORoCaOQQAvD_BwE&gclsrc=aw.ds

Tuttlinghorn

Thanks for those suggestions.

there’s one feature I should have included above - ‘pure sine wave’ output

the requirement is to ensure that a gas water heater stays working for as long as possible in between power cuts (the heater heats water for washing plus heats the apartment )

The UPS/ inverter would need to be permanently connected from the mains to the water heater.

When there’s power coming from the grid, the unit would pass this through to the gas heater and also charge the 12v battery

When the grid drops out, the UPS automatically switches to draw power from the 12v battery.

reading the spec of the inverters posted it looks like they’re designed to charge / discharge a battery as opposed to only using battery when there’s a power cut ?

( also they are modified sine wave vs pure sine wave - the guys in Ukraine reckon this is important to ensure the setup will work )

Tuttlinghorn

Thanks for this. I replied to another post above - unfortunately the requirement is more than the inverter from the 12V battery

10-10-20

also they are modified sine wave vs pure sine wave - the guys in Ukraine reckon this is important to ensure the setup will work

I'm not sure it will matter with a gas heater, I don't know if it really needs pure-sine wave.

Tuttlinghorn

Thanks - the guys on the other end are pretty sure on the spec needed.

In the end they’ve tracked one down - in Riga.

thanks for the input folks !