# How long does it take to charge your batteries?Updated 3 months ago

__Short Answer:__

__Short Answer:__

- 375wh (10.4ah) batteries take roughly 5.2 hours to charge
- 490wh (13.6ah) batteries take roughly 7 hours to charge

__Longer Answer__

__Longer Answer__

Let's calculate charging time using the amp output from you Vvolt charger! To calculate charge time using amp output instead of watts, you'll need to convert amps to watts using the voltage of the battery, because watts is a measure of power (which is voltage multiplied by current in amps). Here’s how you can do it:

**Know your battery capacity**:

- Gen 1 bikes (Alpha/S, Proxima, Centauri/S, Sirius are equipped with 375wh batteries, and some people were able to purchase our 500wh battery when it was in stock!
- Gen 2 bikes (Alpha II, Slice Lite, Centauri SE/II) are equipped with either a 375wh or 490wh battery

** Understand the charger output**:

- Vvolt supplies a UL-certified 2amp charger with all ebikes. We'll be releasing a 4amp fast charger soon!
**All Vvolt ebikes are 36v!**

**Calculate the charger output in watts: **

- Multiply the charger output in amps (A) by the battery voltage (V) to get the output in watts (W).
- The answer is 72w, by the way!

**Calculate your charge time:**

- Charge time =
__Battery capacity (Wh)__ - Charger output (Wh)

Let's check out math! If the battery capacity is 490Wh and the charger output is 72W, then the charge time is roughly 6.8 hours!