November 18, 2020
BATTERIES: WHAT DO ALL THE NUMBERS AND TEXT MEAN?
Maybe you are looking into ebikes for the first time. Perhaps you have been looking for a while. Regardless, at some point, you are going to see some strange measurements like 36V 12Ah, or maybe 500wh pertaining to batteries. What does it all mean?!
Well. like many things in life, a quick explanation can go a long way.
Let’s start with the most common two, V and Ah.
The V you see in the measurement stands for volts. The easiest way to think about this is raw power, similar to a car that has more horsepower. This is a measurement of how much electricity is leaving the battery and pushing the motor and taking you forward. Volts come in many sizes, for example, the most common are 36V or 48V. The bike with the higher volt battery will typically be able to climb the hill with more speed and more torque. A lot of people when shopping for ebikes equate the bikes motor (measured in watts which is a W) to the capabilities of a bike. This measurement isn’t all that it seems because the W (watts) only refers to the capabilities of the motor so long as it has a battery that can sustain it. So in this case, a 36V battery with a 2500W motor is going to be less powerful than a 48V with a 750W motor.
The other measurement is Ah which stands for amp hours. For this one, you can think of duration. The more amp hours (or Ah) you have, the longer the battery lasts on a charge, or in the case of ebikes, the more range you have. So for this example, we will use a DŌST battery. The standard battery 48v 14ah which means you will have high power and above-average range. If we looked at another bike that was 48v and 8ah, that means that while the bike may be powerful, the range will not last very far. Or if we flip it and make a battery that is 24v and 20ah, then we have a very weak bike that can go for miles and miles.
So now that you have the hang of it you may think that 2 batteries have double the power! Well not exactly, the way the dual battery system works, the volts do not stack. However, the amp hours do! So when you have a dual battery system, it gives you more range. In the case of the DŌST bike, you get a combined total of a whopping 24.4ah!
Now for those of us that are a bit nerdy, we can dig into WH, which stands for watt-hours. Watt-hours are not commonly used to describe bike batteries, but some companies use them as a measurement. Watt-hours are basically volts times amp hours. So, v * ah = wh. Similarly, watt-hours divided by volts will get you the amp hour rating. Most bikes will be 24v, 36v, or 48v. So wh / v = ah. Some cute little ways to do math around the batteries. But still, it boils down to volts (power) and amp-hours (range)
Hopefully, this helps you in your search! Stay tuned for more pro tips on how to research ebikes!