Battery Charger Selection

To suggest a battery charger to meet your needs, could you advise:

a) Type of batteries (e.g. wet/flooded lead acid, gel cell)

b) Capacity at 20 and 100 hour rates

c) Automatic or manual charging desired

d) Frequency and duration of each charge cycle

e) Voltage of the battery bank

f) Generator rating

Battery Chargers for Motor Homes

There are several options for keeping your auxiliary battery in your motorhome charged. Which option is the best for depends on your driving patterns, your electrical loads and where you will be staying. Some folks only want a few lights and a small radio. Others require a fridge, television, fan and maybe even a microwave oven and an air conditioner!

a) BATTERY ISOLATOR; This device allows you to charge an auxiliary battery from your vehicle alternator while you are driving.These are fairly economical and can be fitted by an auto electrician. If you plan on driving every few days for a few hours, this may be all that you require to keep your battery charged.

b) MAINS CHARGER; If you plan on staying in powered caravan sites most nights, you could get a fairly small automatic battery charger which will charge your battery while you are connected to the mains power (grid).

c) FUEL GENERATORS: If you are going to be camped away from the grid and stationary for more than a few days, you will probably need either a gen set or solar panels to keep your battery charged. If you have large electrical loads like an air conditioner, you will probably require a 240V AC gen set. You can then connect a mains powered battery charger to this.On the other hand, if you don't have any large 240V electrical loads, then a smaller petrol powered 12/ 24 volt battery charger would be more efficient. However, generators have a lot of disadvantages. You need to carry fuel and they make noise and fumes. Your neighbours in the park or campground may not appreciate your noise! You also need to remember that you can only charge a battery at something like ten to twenty percent of its capacity. So if you have a completely discharged battery it will take at least several hours to charge it up which is a long time for a generator to be on for.

d) SOLAR PANELS: Solar photovoltaic (PV) modules are an ideal way to charge your batteries. While they have a high capital cost, they are maintenance free and should add to the resale value of your motorhome. You should have your loads assessed by an accredited solar installer so that the system will meet your needs. Don't buy a fridge until you've discussed it with your solar supplier! Solar panels need to be in full sun to operate to their full capacity. Most people prefer to mount their panels on the roof - 'Out of sight, Out of mind' so to speak. The only disadvantage is that it means that this portion of the vehicle must be parked in the sun. This can be somewhat annoying on a hot summer's day. The other alternative is to have your solar panel on say a ten metre lead which allows you to park under a tree and place the panel out in the sun. Depending on where you are parked, theft may be a worry with this method if you aren't nearby.

CONCLUSION: All the methods of keeping your batteries charged have their good points and their limitations. Many people will need to select at least two methods to meet their requirements.

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