Whether it is for a trip to the snow, where the extreme cold can kill a starting battery literally overnight OR for backup at any time, the latest type of emergency starter packs are virtually essential. These range from “cheap and cheerful” units to seriously professional models, but if getting out of trouble in some remote location is considered, the latter are truly worth the extra money. GCA do not supply these units but will recommend one that will suit your particular needs and vehicle.
The second battery option
Anyone adventurous enough to use an electric winch running from the starting battery OR plug a fridge or other high-current demanding appliance into an existing lighter socket and leave it running overnight can pretty well be assured that the vehicle will not start in the morning. A current draw of 5 amps for a 12V fridge is not uncommon. Even cycling at 50% in 12 hours this means 30 amps of battery power has been used.
Starting batteries are designed to deliver high current for a very short time so when subjected to demand over a long period, the battery life will be seriously and adversely affected. What is needed is a deep cycle battery, designed to deliver lesser current over a long period and be capable of effective recharging..
On older vehicles – like the Classic Range Rover and Discovery 1, fitting a charge-splitter was a reasonably straightforward job, requiring the addition of an isolator unit to separate the two batteries. The better units offered automatic monitoring of battery state to direct the charge to whichever one needed it. They combine diode protectors and solenoids, a large heat-sink and are relatively easy to install.
Vehicles after about 2000
NEVER attempt a DIY solution. Every vehicle model is different and wiring in the wrong equipment can mean disaster because the installation on these models is usually complex
Consideration must be made for the existing circuitry because even if the computer controlling the vehicle-charging is adjustable, a “one size fits all” arrangement is hardly ever appropriate. The wrong setup will mean at best, the second battery is never charged to its full capacity or in a worse-case scenario means an ineffective setup can kill the computer.
This is especially the case with 2010 and later models (both common rail diesel and petrol engines) fitted with variable voltage alternators that will output a voltage anywhere from 12.3V to 15V. For this reason it may not charge either the starting or the second battery effectively. It also may apply too high a voltage and shorten the life of the auxiliary battery.
Graeme Cooper Automotive will not only help you to select the appropriate system for your particular vehicle, but will install it professionally and safely.
Where to put the second battery
Up to and including the Discovery 3 and Classic Range Rover models, it is possible to fit a second battery in the engine bay, though this may mean selecting a small sized unit and invariably repositioning some components. In later vehicles, the only real option is to locate the second battery in the load space at the rear of the vehicle, though this means losing some effective storage space and running long cables. The second battery must be located in an accessible position and it must be firmly secured to prevent it from being thrown around or turned over.
The emergency starter pack is the best all round solution for most situations, but if serious long range trips involve running a 12V fridge OR if an electric winch is used frequently, the installation of a dual battery system may be a worthwhile investment.
Consulting GCA is strongly recommended