# How do you power large resistive loads on a small inverter at reduced power?

#### Ian0

Joined Aug 7, 2020
471
Re the battery, I've attached the datasheet for the one I intend to buy. 10kg and costs €120, and rated for 300 cycles at 100% depth of discharge. I was rounding-up when I said 40Ah, it's actually 33Ah @ C10 and 36Ah @ C20.

Do you know what a tubular-plate 40Ah battery would cost (and whether it's bigger and heavier?). This application needs to be portable, it's primarily for acting like a mini indoor generator for running low-power essentials during power cuts (computers, modem, lights and stand fans).
Unfortunately, I haven’t seen any below 84Ah. And as they are flooded batteries, portability isn’t a strong point.
https://www.forklift-batteries.co.uk/sunlight-british-standard/

#### LMF5000

Joined Oct 25, 2017
87
Smart move! But the calculations are more favourable than you thought.
Take two elements in Parallel and rewire them in series gives FOUR times the resistance, and a quarter of the power.
i.e.
resistance of 1500w at 230V = 35Ω, which is two 70Ω elements in parallel.
in series they are 140Ω. Power = 375W
*facepalm* you're right! I somehow forgot that 1400W between two elements in parallel means 700W per element.

I'm curious to hear your experience with tubular batteries. I can't find any local prices but the Exide flooded 40Ah model seems to weigh 23kg

#### Ian0

Joined Aug 7, 2020
471
If I remember correctly, these toasters have a cable between top half and bottom half, so it should not be beyond the wit of man to add a switch, to be able to select full and low power.

#### Ian0

Joined Aug 7, 2020
471
I'm curious to hear your experience with tubular batteries. I can't find any local prices but the Exide flooded 40Ah model seems to weigh 23kg
the 1000Ah version which weighs in at 1.6tonnes seems to last about 10 years, being discharged to 50% every day.

#### AlbertHall

Joined Jun 4, 2014
10,393
Or, portable, cheap, environmentally friendly: