Charger Overview

CHAPTER 9 The Charger and Electrical System

An efficient charger is an indispensable part of any electric vehicle.

The charger is an attached and inseparable part of every electric vehicle battery system. Discharging and recharging your batteries are opposite sides of the same coin; you cannot have one without the other. As you learned in Chapter 8, how you recharge your batteries determines both their immediate efficiency and ultimate longevity. As with motors, controllers, and batteries, technology has also made today’s chargers superior to their counterparts a decade ago.

Because your motor, controller, batteries, and charger are also inseparable from the electrical system that interconnects them, it too is covered in this chapter, along with the key components needed for its high-voltage, high-current power side and its lowvoltage, low-current instrumentation side.

In this chapter you’ll learn about how chargers work and the different types, meet the best type of charger to choose for your EV conversion today (used in Chapter 10’s conversion), and look at likely future charging developments. You’ll also look at your EV’s electrical system in detail and learn about its components so when you meet them again during Chapter 10’s conversion process, they will be familiar to you.

Charger Overview

Chapter 8 dealt with discharging and recharging; now we’ll take a closer look at the recharging side. It’s a wise business decision to invest a few hundred dollars in a battery charger that gets the most out of a battery pack that can cost a thousand dollars or more and might be replaced several times during your EV ownership period. An efficient charger is an indispensable part of any EV.

The objective here is to give you a brief background and get you into the recommended battery charger for your EV conversion with minimum fuss. You have three battery charger choices today: build your own, buy an offboard charger, or buy an onboard charger. We’ll look at each area in turn and give our recommendations. Let’s start with a look at what goes on during the lead-acid battery discharging and charging cycle to understand what has to be done by the battery charger.