Battery Cycle Life Calculator
Estimate how long a pack lasts before it fades to ~80% capacity, and roughly how much capacity is left today.
Estimated battery life
A rated cycle count is the number of full charge/discharge cycles before a pack fades to about 80% of its original capacity. This models the fade as linear. Partial top-ups count as a fraction of a cycle, so charging little-and-often is gentler than these round numbers suggest.
Why range shrinks over the years
A battery doesn't fail all at once — it fades. Each charge cycle chips away a tiny amount of capacity, and the industry convention is to measure a pack's useful life as the point where it holds about 80% of its original charge. Past that, the device still works, but your range keeps creeping down.
Knowing your rated cycles and how often you charge lets you put a rough timeline on that fade — useful for deciding whether a range problem is normal aging, and for planning when a replacement pack might be worth budgeting for.
Frequently Asked Questions
What does 'rated cycles' mean on a battery?
A cycle rating is the number of full charge-and-discharge cycles a pack can do before its capacity fades to about 80% of new. Many lithium packs are rated somewhere between 300 and 1000 cycles. It doesn't mean the battery dies at that point — just that it now holds noticeably less than when it was new, so range drops.
How do you turn cycles into years?
Multiply your charges per week by 52 to get charges per year, then divide the rated cycles by that. Charge three times a week on a 500-cycle pack and you reach the 80% mark in a little over three years. Charge daily and you get there much sooner. It's a planning estimate, not a countdown.
Does a partial charge count as a full cycle?
No — and that's important. A cycle is a full charge's worth of energy, so two half-charges count as roughly one cycle, not two. That means topping up little and often is gentler on the pack than the raw 'charges per week' number implies, and this tool's estimate is deliberately conservative on that front.
How is the remaining-capacity figure estimated?
It models the fade as a straight line from 100% when new down to 80% at the rated cycle count, based on how many cycles your age and charging habits imply you've used. Real batteries don't fade in a perfectly straight line, but a linear model is a reasonable, honest first approximation for planning.
How can I make the battery last longer?
The habits that help most: avoid routinely charging to a full 100% or draining to empty, don't leave it sitting fully charged or fully flat for long periods, charge and store it at moderate temperatures rather than in freezing or hot conditions, and use the charger that came with it. None of this stops aging, but it slows it.
Estimates only — real battery aging depends on cell chemistry, temperature, and how it's charged and stored. Ride safely, wear a helmet, and follow your local law.