Split Charge Kit (Made To Measure)

Price:  Please call for info(£0.00 Exc. VAT)

Product code:  P00851


Non-stock item - longer despatch time  

Non-stock item - longer despatch time

  (2 Reviews)

Typical kit price is around £95 inc. VAT (based on 3.0m of red and 0.5m black cable)

Includes FREE crimping tool!


If you plan on having a second or 'leisure' battery to run your electrics in your boat, campervan or motorhome then you'll need a split charge system. These allow you to re-charge your leisure battery from your alternator, so while your engine's running your leisure battery is being topped up. Whilst there are many 'one-size-fits-all' split charge kits on the market we believe that every installation is unique and so prefer to offer you a pre-assembled made-to-measure solution that fits perfectly and has everything you need included in the kit.

Our motorhome, boat & camper van split charge kits feature a dual sensing Voltage Sensitive Relay that starts charging the leisure battery when it detects 13.3V at the starter battery (indicated by a red LED) and stops when it drops to 12.8V. The batteries are always disconnected when the engine's not running so you can't flatten your starter battery.

In addition, because our relays are dual sensing they operate in both directions, so will enable you to charge your starter battery when your leisure battery is connected to a mains charger or solar panel.

Our kits come assembled using the highest quality components and manufactured to professional standards so you can be sure they will provide you with good service for many years. 

IMPORTANT NOTE: Voltage Sensitive Relays are NOT suitable for vehicles with 'smart' or 'intelligent' alternators that are controlled by the ECU. As a guide this applies to vehicles having engines that comply with Euro5 emissions standards and onward, often also incorporating regenerative braking (if in doubt please consult your vehicle manufacturer to confirm). If your vehicle has a smart alternator then you will need to use a battery-to-battery charger instead of a VSR (we can still supply this as a kit  - please contact us for details).

Find out more about split charging in our Knowledge Centre

Advantages of our kits 

  1. They are a 'plug and play' kit, ideal for DIY installation.
  2. There are no excessive cable lengths as in some off-the-shelf kits (we make to your requirements) so you don't pay for more than you need and you have a neat and tidy installation.
  3. They use a dual sensing Voltage Sensitive Relay that has sufficient capacity for the most demanding applications and eliminates the need to cut into the factory wiring.
  4. The cables are terminated using copper tube terminals with a professional hex crimp and covered with heat shrink sleeving to resist corrosion.
  5. We only use dedicated Hi-Flex PVC battery cable (manufactured in the UK) not general, lower amperage cable that won't cope with the maximum charge output of your alternator (we can also use tinned battery cable in the kits on request).
  6. They include all the parts you need to complete the installation, saving you time and effort.

Each kit includes:

  • 1 x 140A Voltage Sensitive Relay (67 W x 67 L x 62 D mm)
  • 4 x red 16mm²/110A Hi-Flex PVC battery cables to connect from starter battery to leisure battery (via the fuse holders and relay)
  • 2 x 80A Midi fuses and fuse holders (70 L x 30 W x 22 D mm) to protect the circuit
  • 1 x black 16mm²/110A Hi-Flex PVC battery cable for the leisure battery to earth
  • 1 x positive battery terminal clamp (for the leisure battery)
  • 1 x negative battery terminal clamp (for the leisure battery)
  • 2 x PVC battery terminal covers 
  • 4 x no.8 x 1/2" self tapping screws for fuse holders
  • 1 x no.14 x 3/4" self tapping hex screw for the leisure battery earthing cable
  • Cable ties
  • Full instructions for installation
  • FREE insulated terminal crimping tool

How do I order?

Simply send us the necessary cable length information using the enquiry form below and we'll send you a quote (please note that in requesting a quote there is absolutely no obligation to purchase).

Before completing the form you might want to download the installation instructions (click on the PDF download icon) to familiarise yourself with the system layout and help you measure up, and also read the guidance notes below.  Download instructions

Enquiry form

Please enter the cable lengths you need in increments of 0.1 metres (m), e.g. 2.0m, 1.5m etc. The battery to fuse lengths (cables 1 and 4) should be as short as possible - ideally less than 30cm.

Cable 1 - Starter battery +VE to Fuse Holder 1: *
Cable 2 - Fuse Holder 1 to Voltage Sensitive Relay: *
Cable 3 - Voltage Sensitive Relay to Fuse Holder 2: *
Cable 4 - Fuse Holder 2 to leisure battery +VE: *
Cable 5 - Leisure battery -VE to earthing point: *
Earthing point can be vehicle chassis or starter battery -ve terminal
Vehicle Make/Model/Year: *
This information will help us ensure that the split charge system will be suitable.
Further info/comments:
Name: *
E-mail: *
Telephone no.:
We need to check you're human! Please add the two numbers above and enter the result.

Guidance notes

  • Before measuring for cable lengths, determine your Voltage Sensitive Relay and fuse holder locations, ensuring that there is sufficient space to mount them (please see dims above).
  • When measuring for cable lengths please measure the actual routing path for the cable, not simply the straight line distance.
  • Try and place the fuses as close as possible to the batteries (within 30cm ideally).
  • Please be aware that we cannot accept responsibility for problems encountered during installation as a result of any incorrect measurements given to us. If in doubt please contact us first.
  • Our standard terminal hole size for the starter battery +ve connection is 8mm so we recommend you check that a suitable size stud exists on the starter battery +ve terminal clamp.
  • If you have any other requirements, e.g. different terminal hole sizes, tinned cable etc., please mention them in the 'Further info/comments' field or contact us to discuss. We will try our best to find a solution that meets your needs.
Average Rating (2 Reviews):  
Write a Review and share your opinions!

Very good
Wednesday, 4 November 2015  |  Simon

I bought one of these for my t5, it came with everything I needed and very clear instructions for a diy installation. The guys at 12v planet also gave very good advice about the kit and a few extra bits I bought for my camper conversion.

Tuesday, 26 November 2013  |  Ralph

12 Volt Planet were extremely helpful and as a result the kit was sized correctly, easy to fit and worked first time - had never fitted anything like this before. Highly recommend the kit and the service provided.