Battery charging Qs (Autotrail Cheyenne)

Nov 6, 2021
I think the battery is kna. . . ahem, past its prime, so I'm almost certainly going to have to replace it anyway, but as the camper is new to me, I am anxious not to ruin the replacement by incorrect setting of switches. To which end I am reading the instruction manual intensely.

There is a three position switch for supply selection, MAIN uses the cab battery, AUX the 'caravan' battery, and middle position for off.

"The caravan or cab batteries will be charged from the mains supply when connected.
Selection is achieved by using the battery selector switch"

(The charger unit also needs to be on, fairly obviously.)

I deduce from that, that the two batteries are not linked, so presumably also the auxiliary battery won't charge from the engine?

Earlier in the manual, it says:
"12 volt Supply
Two batteries are fitted to the Motor Caravan, the main vehicle battery and auxiliary battery to run the caravan 12 volt circuits. A charging unit can be switched from the vehicle alternator to the mains electricity supply if this is available."

The first sentence is straightforward enough, but the second . . .Does it mean that the charging unit automatically runs from the engine when it's running? If not, how do I switch it to do so?
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Mar 14, 2005
As you seem to have deduced, there are two batteries in your Autotrail.
The main engine battery and the leisure battery.
There is no direct connection between the two , as if there were, it is very possible that the power from the engine battery could be used up by the internal leisure equipment, leaving not enough to start the engine !

There is , as is the case in most caravans, an automatic switch over to charge the leisure battery from the engine alternator, but only when the engine is running as well the alternator charging the main engine battery.

When on mains hookup, both batteries are charged from the PSU as long as the battery charger is switched on.

Occasionally it may be needed that that you want power from the main engine battery for a very short time, hence the option to draw from the main battery.


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