Ask someone why they haven't bought an EV yet, and there's a good chance battery life comes up. Concern about battery longevity remains one of the most common barriers to EV adoption. It's also the objection we hear most about vehicle-to-grid (V2G) and vehicle-to-home (V2H): if my battery wears out with use, why would I use it more?
The worry rests on a few assumptions. That lithium-ion packs degrade quickly, that you'll probably need to replace one, and that any extra cycling should be avoided. Years of real-world data now tell a different story, which is great news for the record number of EV buyers in Australia last month.
What the data actually shows
Recurrent monitors tens of thousands of EVs in the United States, and found that the average EV retains approximately 95% of original capacity after five years on the road. Geotab's fleet telematics back that up, putting average degradation below 2% per year. The Geotab figure includes vehicles that were fast-charged regularly, so it's a realistic and non-best-case number. A Swedish analysis of 9,954 battery health tests run between 2022 and 2026 found that after 100,000 km, capacity retention sat between 91.7% to 97.25% across all models examined.
But what if I do need a new battery?
You almost certainly won't. Approximately 1 in 12 EVs built between 2011 and 2016 eventually needed a new battery pack - and that group is dominated by early Nissan Leafs built without active thermal management. The tech has moved on since then, and for vehicles built from 2022 onward, the replacement rate is 0.3%.
Even in that unlucky 0.3%, you're likely to be well covered. Every EV sold in Australia comes with a separate high-voltage battery warranty of at least seven years, most commonly eight years or 160,000 km, and typically guarantees 70% capacity retention.
What actually wears a battery out
Degradation isn't random and a consistent set of factors has been found to accelerate it, and they're worth knowing about as an owner:
- Sustained high temperatures
- Long stretches sitting at a very high or very low state of charge
- Frequent or exclusive high-power DC fast charging
So does V2G wear out my battery?
The intuitive objection to bidirectional charging is that more cycling must mean more wear. Early experimental and modelling work, seemed to support that fear, but those studies imposed deep, accelerated cycling on the battery. Later research that models degradation mechanisms has qualified the finding substantially, and showed that managed bidirectional charging can actually help reduce battery capacity fade over time.
The distinction that matters is between unmanaged cycling and managed dispatch. Dispatch that respects temperature and state of charge can help the battery stay within the duty cycle the battery was engineered to handle, and in some configurations is better for health than just leaving the battery alone.
How Amber handles it
In Amber's V2G program, we're working directly with EV manufacturers to honour their specified discharge controls, including state-of-charge windows, discharge power and total cycling, so every discharging event stays within the operating envelope your battery was warranted against.
The evidence has moved past the fear. If battery wear was the thing holding you back from buying an EV, or doing V2G, the data says it shouldn't be.
Want your EV doing more than sitting in the driveway? Register your interest in Amber's V2G program.
