Truma Mover S - Battery Problem

[Guido]

I have recently fitted a new Truma Mover S to our Burstner and followed all the fitting instructions to the letter. The battery on the van is an 85ah which has been untouched for two years and we always use electric hookups.

When I use the mover it only works for about 20 seconds or so before cutting out - it states in the instructions that the battery must be over 11v or it will not work. Could the mover take so much power that it flattens the battery to under 11v in such a short time? I have only ever used the charger on the caravan and I have read that this charger only charges to approx 80% of the battery's capacity. Does this mean I need to take the battery off and charge it with a car charger occasionally, could my caravan charger be faulty, or do I need to buy a new battery? I have seen it recommended that a powerful car battery could be a good idea.

Any help would be really appreciated as I thought fitting the mover would make my life easier and I don't fancy lugging heavy batteries around every time I want to use it!

 

[ProfJohnL]

Hello Guido,

The symptoms you describe do sound as though the battery is not able to supply the current the mover needs. When this happens, the battery reduces its terminal voltage, and most likely in this case the mover controller sense the low voltage and cuts out.

From the symptoms you describe, my initial thoughts are that the battery may need to be replaced.

You might also benefit from obtaining a multistage charger to use instead of the caravans one internal unit. These are capable of fully recharging and maintaining a battery in tip top condition. (e.g. CTEK)

Most people only use the mover for about 5 Min at a time. An 85Ah battery should be more than capable of providing the power for that especially if you only use sites with mains hook ups.

 

[Dave_374330759]

Sounds like your battery has lost its capacity and its internal resistance has increase due to undercharging. The charger in the van will only charge the battery to about 13.8volts, this over time will cause sulphate to build up on the plates which will reduce its capacity and ability to supply a heavy current. You may find that the lights and TV seem to be ok but if you can put a voltmeter across the battery terminals (make sure its on volts) and try the mover You may be surprised to see how low the voltage can drop. Looks like you need a new battery. They do need a bit of TLC to make them last. Ideally you should give the battery a decent charge with a multistep charger every couple of months and never ever let the battery go flat. I only buy cheap leisure batteries and they last 7-8 years both on my boat and in the caravan.

 

[Guido]

Many thanks for your help - looks like it will have to be a new battery then.

 

[IanMc]

hello Guido

It may need a new battery. If a 110ah will fit I would recommend this battery with a mover. I had similar problem with my previous mover. I bought a new 85ah battery and the problem continued. Got mover service guy out and he recommended a 110ah battery. Had this fitted on both now and not had a problem.

Regards

Ian

 

[RogerP]

I'm not technically savvy on these things , but both the vans I've had the dealer (different ones) said to fit the larger 110 battery.

 

[Mike_5041144]

Hi Guido

I too have this problem with my Truma. Even fitting a new 110ah battery made no difference. However, where I stand in relation to the van's mover control unit seems to affect the stop/start pauses. It is a super mover but annoying to use.

 

[TD42]

Hi Guido, before you buy a new battery I suggest that you buy or borrow a multi stage charger with Pulse maintenance mode try charging your present battery for up to a week as the cells may only be sulphated, A multi stage charger can re energise an old battery by de sulphating the plates,In any case it is not money wasted as you should recharge your van battery with such a charger after each time away to keep it in good condition.

You are correct in what you summise about the charger fitted in most vans which causes the plate sulphating in prolonged use