Author Topic: Wiring a sidecar - Series or Parallel?  (Read 296 times)

Offline owain

  • A's Good Friend
  • ***
  • Join Date: Mar 2017
  • Posts: 145
  • Karma: 4
Wiring a sidecar - Series or Parallel?
« on: 17.09. 2018 17:32 »
I've had my sidecar on my A10 for a while now but I can't ride it with all the lights or the battery goes flat within minutes. It looks like the battery is charging whilst I'm riding with just the rear lights on but as soon I turn the headlights on the amp meter goes waaaaay negative and headlamps begin to dim within minutes. All the bulbs are 6v and I've arranged the circuitry in parallel....Any ideas how I could solve this? I'm wondering whether I should wire the sidecar lights in series instead i.e. so that the overall circuit is 12v and has lower current?
Sweden & North Wales
'50 BSA A10
'69 BSA A75R

Online Triton Thrasher

  • Scotland
  • Wise & Enlightened
  • *
  • Join Date: Feb 2009
  • Posts: 1618
  • Karma: 20
Re: Wiring a sidecar - Series or Parallel?
« Reply #1 on: 17.09. 2018 17:53 »
What is the wattage of your headlight bulb?  It probably can’t handle more than 30W full beam/24W dip.

LEDs in the rear and sidecar lamps will use less power.

Offline lawnmowerman

  • Resident Legend
  • *****
  • Join Date: Dec 2009
  • Posts: 624
  • Karma: 8
  • 1959 Super Rocket. Kent, England
Re: Wiring a sidecar - Series or Parallel?
« Reply #2 on: 17.09. 2018 18:20 »
Fit 6v LEDs all round including the headlamp bulb and you will be able to leave the lights on all the time - even during the day for extra visibilty.
Wiring filament lamps in series will halve the light output as you will only be dropping 3v across each bulb so is not recommended.

1959 A10 SR
1938 Wolseley 14/60
1955 Ferguson TEF20 tractor
1965 Ferguson 135 tractor
1952 Matchless G80 rigid
1960 BMW R60
1954 Matchless G80S
1955 Ariel 500 VH
1951 Sunbeam S7DL
1960 Matchless G12 with Watsonian Monza
......and loads of lawnmowers

Too old to Rock and Roll but too young to die  (Jethro Tull 1976)

Offline RayC10

  • A's Good Friend
  • ***
  • Join Date: Oct 2017
  • Posts: 51
  • Karma: 0
Re: Wiring a sidecar - Series or Parallel?
« Reply #3 on: 18.09. 2018 07:11 »
Defo not series! I had a sidcar on mine for many years. with a couple of 5w  lamps on the side car and even  with indicators fitted had no probs.. Is there a wiring fault? If not, LEDs if you can get them to work on 6v without flickering. Back in days of old we used to use a small car battery in the chair boot but it realy is limited by the dynamo output. Add up the total lamp watts and compare that to the rated dynamo output.
Does the ammeter go "less negative" when you apply some revs?

Offline duTch

  • Ricketty Rocketty Golden Flashback
  • Wise & Enlightened
  • *
  • Join Date: Oct 2011
  • Posts: 4539
  • Karma: 41
Re: Wiring a sidecar - Series or Parallel?
« Reply #4 on: 18.09. 2018 09:10 »
 Series is not an option unless 12V battery and want to run 6v lights (but wiring and charging would be tricky *pull hair out*)......Best to invest in as many LED lights as you can, I recently added a 6V LED and it works well and from memeory  *conf2* only draws about ~2A I think the same as 5th Gen one from here;

 Also having a sidecar you be able to use a higher capacity battery (or bank in parallel ) for extra storage for use at low speed, but would obviously need to be recharged with a compensatory higher speed ride after (or trickle-charge overnight)

 The trouble with tail-light and pilot bulbs with bayonet bases is they are flimsy and fall apart, but this can be rectified by putting heatshrink over the pilot light lost one of the SMD's so now I need  to re-attach the with more micro-solder  *pull hair out*

Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy