24V 12V DC DC Converter
24V 12V DC DC Converter
Find out how you can use a 24V battery (bank) to power 12V devices
storage | electric circuitThere are many advantages to using a 24V or 48V
battery bank rather than the more commonly found
12 Volt. Primarily, the
cable used to connect the alternator/
generator to the battery bank, and from the battery bank to the load appliances can be thinner since
line losses (energy lost as electricity passes through cable) are less the higher the voltage transmitted.
While affordable
power inverters are available for use with 24V batteries and battery banks, other useful items are
much more expensive if rated for use with 24VDC rather than 12VDC - for example, Sat-Nav chargers,
LED lighting, and the huge array of items designed to be used in-car or with caravans and powered by 12 VDC.
24V to 12V DC-DC Converter
If you have a
24V lorry battery or a
24V battery bank, but you still want to be able to power 12VDC rated appliances, you need a
DC-DC Converter. These are designed to give a regulated 12VDC output from an input voltage of around 24V-30VDC. These can be quite
cheap to purchase as there is a large market of
lorry drivers who want to be able to use 12V rated kettles and televisions etc in their 24V wired cabs.
The key things to look for are the maximum
load current rating (measured in Amps). This tells you how much current the connected 12V rated appliance can safely draw. The second is the
efficiency. Ideally you do not want to be wasting stored battery charge as heat, so try to purchase the most efficient DC-DC converter you can afford.
Pictured above is an
8 Amp rated
24V-12V DC-DC Converter. This has been designed to be plugged straight into the 24V cigar lighter socket in a lorry cab, but the plug can easily be cut off and the bare wires connected to a 24V battery bank. The two output sockets are for devices which can be powered directly from standard car
12V cigar lighter sockets. One device can be powered at up to 8 Amps (100 Watts), or two at up to 4 Amps each. The built in
on/off switch is very useful for saving battery charge when no loads are present.
This basic 8 Amp unit was found on
eBay UK in July 2008 priced at
£15.75 plus £2.45 postage.
Pictured above is a higher quality, higher current rated
24-12V converter. Rated at
16 Amps (200 Watts), this can be used to power large laptop computers and 12V rated kettles with ease. It can accept inputs from 22-29 VDC, and uses just 30mA of current when switched off.
Added features include
low voltage protection (prevents battery being excessively drained), and
over voltage protection (stops converter being damaged if connected to voltage source exceeding 29V.
Connections to this converter can be made by 12V sockets, pillar terminals, or the supplied cables.
Again this converter was found on
eBay UK in July 2008, but a bit more pricey at
£44.99 plus £3.50 postage.
Buy a 24-12V DC-DC Converter
If searching eBay for a
24V-12V converter we have found the best search to be
24V Converter, with a few hundred items being available for sale at any one time.
UPDATE March 2011 - Since this article was first published, the prices of these converters have dropped considerably, and their availability has increased. Pictured above is an example 30A 24V to 12V power supply converter sold for just £10 including UK delivery!
Article Last Modified: 12:20, 15th Mar 2011Comment on this Article
If you have any comments on this article, please email them to
neil@reuk.co.uk.
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