View Full Version : Stuff Iíve Learned- Batteries

18 August 2010, 0814
Summary of my battery basics on The Electric Chronicles-


Iím going to go out on a limb and say the batteries you use on your bike will, more than any other factor, determine how the bike will perform. The batteries determine how far you ride, how much acceleration you have and the weight of the bike. Theyíre also likely the biggest single expense.

The ideal battery for a bike is compact, since we donít have a lot of room. We want a battery with a lot of capacity, so we have good range, and we need something that can discharge (for acceleration) and recharge fast. We want as little weight as possible, since weight sucks horsepower and affects handling and range. We also need a battery thatís safe, and wonít spill.

Here are the ratings we need to look at.

Ah, or amp-hours, shows the capacity of the battery. Itís based on a number of amps discharging over a period of time, and the more amp-hours, the longer the battery can power your ride.

C-rate. This is the charge/discharge rate, which tells you how much the battery can dump to your motor, and how fast. Itís based on the internal resistance of the battery, and is a function of the battery design and construction.

Other stuff- Weight and size. Cost. Construction. Voltage. Other things to make the system run. (BMS)

The real choices for batteries for bikes comes down to only a few options, and frankly, there arenít any silver bullets here. Trust me, thereís nothing out there that hasnít been thought of, or tried, and there are some really good reasons why the vast majority of builders have settled on what they use. Hereís the list.

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