Three routes, three price brackets
| Approach | Typical cost | Install | Covers |
|---|---|---|---|
| Portable station, plug things in | $700–2,500 | None | Whatever you plug in |
| Portable + transfer switch | $1,200–3,500 | Half-day electrician | Selected circuits |
| Installed home battery | $10,000–20,000+ | Full install & permit | Whole home, automatic |
Why the gap is so wide
The jump from a couple of thousand to twenty thousand is not mostly battery. It is labour, permitting, inspection, an inverter rated for your whole service, and automatic transfer gear. The cells themselves are a minority of the bill.
That is worth knowing because it means the cheap routes are not a compromised version of the expensive one — they are a different product solving a narrower problem, often the problem you actually have.
The question that decides it. Do you need power to arrive automatically, or are you willing to plug things in? Automatic switchover is most of what you are paying for at the top end.
Route 1: portable station
Buy a large station, run extension leads to the fridge and router when the power goes. No electrician, no permit, nothing attached to the house, and it comes with you if you move. The compromise is that hard-wired things — furnace, well pump, lights — stay off.
Route 2: transfer switch
The value option, and under-recommended. An electrician fits a small transfer switch or interlock so a handful of circuits can be fed from your station. A few hundred dollars in labour turns a portable battery into something close to real backup, and the furnace works.
Route 3: installed system
Everything works, automatically, with no involvement from you. It usually only pencils out when paired with rooftop solar or a punishing time-of-use tariff, and payback periods are long. If you are considering it mainly for outages, price route 2 first.
Running costs
Effectively zero for all three. Charging a 2,000Wh battery costs cents at typical rates. There is no fuel, no servicing, and LiFePO4 packs last thousands of cycles — see LiFePO4 vs lithium-ion.