Mover manufacturers usually recommend a minimum battery capacity for their products, but the capacity will vary with the type of use. A well-charged 85Ah battery in good condition should cope with a long awkward access that will take ten minutes to traverse, but a poorly-charged 110Ah battery after a long weekend away without a hook-up could struggle. A good battery, well maintained, is essential and remember if you need to use the mover extensively to place your caravan into storage a depleted battery will deteriorate much more quickly than a fully-charged battery.
The fixing of a mover may interfere with the function of the spare wheel carrier or jacking brackets, which generally have a predetermined location behind the axle. Locating the mover forward of the axle will resolve this problem. There's also the possibility of conflict between the mover location and shock absorbers if fitted. Where movers are fitted to both axles of a twin axle caravan there may be no alternative but to carry the spare wheel elsewhere other than in the carrier and accept the proprietary jack bracket mounting points may not be usable. Powrwheel offers a kit to move the AL-KO spare wheel clear, but the jacking points still remain lost. Occasionally, heating ducts or water pipes may need to be relocated to allow room for the mover.
The location of the mover will have a small effect on the caravan's noseweight. If fitted in front of the axle the noseweight will be increased slightly and when fitted to the rear of the axle the noseweight will slightly decrease.
Motor mover manufacturers should specify a maximum working limit for their product in terms of caravan weight and gradient.
It is important to check that your requirements are within the limits, particularly if you need to operate on a steep gradient.
A motor mover with a quoted maximum caravan weight of 1,800kg may only be capable of moving a 1,200kg caravan on a one-in-four slope.
Twin axle caravans are more difficult to manoeuvre than caravans with single axles. That means a special approach is needed when fitting a motor mover to a twin axle caravan.
The less expensive option is to fit motors to either the front or the rear axle and operate the system with the jockey wheel raised or lowered to keep the load on the driven axle. Note that a twin axle caravan will not turn almost on the spot like a single axle caravan but turns along a curve, as if being towed. How tight the radius of the curve is will depend on the performance of the selected mover and the surface conditions. There may be situations when uneven ground could leave one or more of the drive wheels off the ground and some twin axle caravans may be too heavy for a single pair of mover motors.
Better manoeuvrability may be obtained by fitting motors to both axles. The downside of this arrangement is the financial cost and extra weight. A twin axle caravan may have a generous payload allowance, but a full set of movers to both axles could take up as much as 80kg of this payload.
Axle movers are engineered to clamp on to modern AL-KO and BPW chassis without any drilling, which is not permitted by the chassis manufacturers as it would weaken the chassis. Other caravans such as early Lunar models with an alloy Knott chassis or specialist makes of caravans like Eriba and Gober may need additional brackets to facilitate the mover installation. For such specialist caravans you will need to consult the mover manufacturer.
Once installed, a motor mover should allow many years of use and most are capable of being removed and remounted on a new caravan subject to the weight being within the mover's weight limit. It's at this stage when the value of stainless steel fixings and good quality paint finishes show.