• on Test & Measurement
  • Published in issue 7/2008 on page 24
About the article

Battery Discharge Meter

Battery Discharge Meter
The author is a particular fan of fishing, and like many anglers is the proud owner of not only a fishing rod, but also a boat: and this is where the electronics comes in. The author's boat has an electric outboard motor, and with his mind wrapped up in his sport it can easily happen that the battery is allowed to run down, leaving the not very enticing prospect of a long paddle home.
Downloading of this magazine article is reserved for Elektor Members only.
Already a member? click here to log in.
Gerber file

CAM/CAD data for the PCB referred to in this article is available as a Gerber file. Elektor Members can exclusively download these files for free as part of their Membership. Gerber files allow a PCB to be produced on an appropriate device available locally, or through an online PCB manufacturing service. Elektor recommends its business partner Eurocircuits as the company of choice for its own prototypes and volume production in selected cases.

Sensor module


R1 = 470Ω

R2 = 3kΩ09

R43 = 1kΩ


C1,C2 = 15pF ceramic, lead pitch 5mm

C3,C4 = 10nF ceramic, lead pitch 5mm

C5 = 100μF 25V radial, diameter 6.3mm

C6,C7, C10-C13 = 100nF ceramic, lead pitch 5mm

C8 = 10μF 25V, radial, lead pitch 2.5mm

C9 = 100nF ceramic, lead pitch 5mm


D1 = LED, red

D2 = 1N4001

IC1 = PIC16F676-20I/P, programmed, Elektor

SHOP # 070821-41

IC2 = 7805

IC3 = ACS750SCA-050

IC4 = MAX232 (DIP16)


K1 = 6-way mini-DIN socket, PCB mount

K4,K5,K6 = spade terminal

2 M3 screws and nuts

F1 = miniature fuse, 1A, fast, for solder mounting

S1 = on/off switch

Mini DIN cable with moulded 6-way plugs for

connection of module

X1 = 20MHz quartz crystal, parallel resonance

PCB, ref. 070821-1, from www.thepcbshop.com

Display module


R4,R5,R7,R9 = 2kΩ7

R6,R8 = 56Ω

R10 = 27kΩ

P1 = 10kΩ preset


C14 = 220μF 16V radial, lead pitch 2.5mm,

diameter 6.3mm

C15,C16,C17,C19-C22 = 100nF ceramic, lead pitch


C18 = 10μF 25V radial, lead pitch 2.5mm

C23,C24 = 15pF ceramic, lead pitch 5mm


D3 = 1N4148

T1 = BC337

IC5 = 7805

IC6 = MAX232 (DIP16)

IC7 = PIC16F628-20/P, programmed, Elektor SHOP

# 070821-42


J1 = 2-way pinheader and jumper

S2 = pushbutton

K2 = 6-way mini-DIN socket, PCB mount

K3 = 6-way pinheader, lead pitch 2.54mm

LCD1 = LCD, 2x16 characters, e.g. EA DIP162


X2 = 20MHz quartz crystal, parallel resonance

PCB, ref. 070821-2, from www.thepcbshop.com

Loading comments...