Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Batteries & Chargers => Topic started by: vosper on June 16, 2009, 11:53:38 pm

Title: charger
Post by: vosper on June 16, 2009, 11:53:38 pm: Hi
Need some i wish to power my charger from mains when at home can i connect to the car battery charger to power the charger to charge boat battery's.
Thanks
Hugh
Title: Re: charger
Post by: malcolmfrary on June 17, 2009, 12:07:52 am: Probably not - the output from most car chargers is unsmoothed, a charger expecting a smooth supply as from a battery might not respond properly.
Title: Re: charger
Post by: Martin (Admin) on June 17, 2009, 03:55:56 am: You could use a laptop power supply or a modified PC power supply.

http://www.modelboatmayhem.co.uk/forum/index.php?topic=13707.msg130944#msg130944

http://www.modelboatmayhem.co.uk/forum/index.php?topic=10935.0

http://www.modelboatmayhem.co.uk/forum/index.php?topic=13707.msg131175#msg131175
Title: Re: charger
Post by: vosper on June 18, 2009, 05:52:19 pm: Hi all
You got me thinking what i had what about a hornby train controller it says 14.2v DC 1.1VA.
Would this do the job.
Thanks
Hugh
Title: Re: charger
Post by: knoby on June 18, 2009, 06:40:17 pm: Hi Hugh the hornby controller doesn't have a hugh output so it depends on what your charging, how fast your charging it & what charger you are using as to what power supply you require. As malcom said some chargers wont like the un-smoothed output from your car battery charger,l however i have used several different fast chargers at home powered from a car battery charger for many years without any problems. As I use a spare car battery to power my charger when I'm in the Field,all I do is put the spare car battery on charge, & then connect the model charger to the car battery & u have yourself a fairly well smoothed power supply. Obviously you have to employ some common sense, don't connect the model charger up till there is a reasonable charge in the car battery, & don't leave the car battery on for several days. failing that a simple smoothing circuit for your car battery charger is very easy to build. pm me if u require help with it

hope this helps Glenn.
Title: Re: charger
Post by: malcolmfrary on June 18, 2009, 09:36:40 pm: Quote from: vosper on June 18, 2009, 05:52:19 pm
Hi all
You got me thinking what i had what about a hornby train controller it says 14.2v DC 1.1VA.
Would this do the job.
Thanks
Hugh
All the Hornby train controllers that I remember were every bit as unsmoothed as the car battery chargers, most just controlled by having an adjustable current limiting resistor under the control knob. To keep life simple for designers and accountants, "electronic" ones worked using a thyristor to adjust the length of time the rectified lumpy waveform was switched on, so not smooth. Later ones were probably PWM, giving full voltage.
Specialist basic model battery chargers are not particularly cheap, but are much cheaper than forking out for early battery replacement. And, of course, there's Martins suggestion of using a PC power supply.