After riding an e-bike for a while, have you ever worried about your e-bike battery’s voltage? It’s normal for battery voltage to drop over time, but how much is okay?
What affects battery sag?
- Battery age: As batteries age, their internal resistance increases, leading to more significant voltage drops under load.
- How you use it: Charging and using the battery a lot can make it wear out faster.
- Temperature: Really hot or cold weather can make battery sag worse.
- Battery quality: Better batteries usually last longer and don’t sag as much.
How much sag is too much?
For a battery that’s several years old, some sag is expected. But if it’s sagging too much, it might be on its last legs. Here are some signs that the sag might be a problem:
- Big drops in power: If your e-bike’s performance takes a nosedive when you’re using it, it could be because of too much battery sag.
- Sudden shutdowns: If your e-bike turns off out of the blue, even when you think it has enough charge, that’s a red flag.
- Battery drains super fast: If the battery percentage drops like a rock when you’re using a lot of power, it might be sagging too much.
With my 2-year-old battery, I’ve noticed:
- The voltage drops quicker when I start from a stop
- Less power on steep hills compared to when the battery was new
- I have to charge it more often
1. What’s your experience with battery sag?
2. How much sag do you think is okay for a battery you’ve been using for years?
Can’t wait to hear your thoughts and experiences! 