Something Draining Batteries

rustynutz

I have the camper (Rimor Superbrig 728 on Merc Sprinter 99 if its relevant) parked up for winter, I usually start it every couple of weeks and go for a short drive to keep everything working. Problem is something seems to be draining both the leisure and vehicle batteries. If I don't go near it for 3 weeks both batteries will be completely flat, not even ignition lights. There is nothing obvious left on. Has anyone any suggestions as to what the problem may be or how I can check what is drawing the power. I currently have removed the leisure battery and have the vehicle battery on charge.

crabbypaddy

rustynutz wrote: »

I have the camper (Rimor Superbrig 728 on Merc Sprinter 99 if its relevant) parked up for winter, I usually start it every couple of weeks and go for a short drive to keep everything working. Problem is something seems to be draining both the leisure and vehicle batteries. If I don't go near it for 3 weeks both batteries will be completely flat, not even ignition lights. There is nothing obvious left on. Has anyone any suggestions as to what the problem may be or how I can check what is drawing the power. I currently have removed the leisure battery and have the vehicle battery on charge.

Turn off everything, disconnect one side of the battery and put an ammeter or a multimeter on 10A range between the battery pole and cable. If your seeing a current draw then start pulling /replacing fuses until you find the circuit causing the problem.

Going for a short drive wont replace the energy lost through self discharge, standby current for central locking etc and starting so they battery would be getting lower every time you start it.

If you're not using an alarm then battery disconnect terminals can be useful to stop stereos, immobiliser, body computers etc. flattening the starter battery.

me_right_one

Batteries just lose charge naturally anyway. If you're not going to be driving it for more than a month, take them out, buy a charger, and charge them up a day before you intend to drive it again.

rustynutz

I have a few motorbikes in the shed parked up over winter and they don't usually discharge after a month of non use, I'm just curious if there is anything specific to motorhomes that may be drawing power that I'm not aware of. Either way I have removed the leisure battery and have the main battery on trickle charge so it's all good. On a side note t.here is a maintenance power setting on the control panel, would it be advisable to leave the 220 hookup plugged in over winter?

crabbypaddy

rustynutz wrote: »

I have a few motorbikes in the shed parked up over winter and they don't usually discharge after a month of non use, I'm just curious if there is anything specific to motorhomes that may be drawing power that I'm not aware of. Either way I have removed the leisure battery and have the main battery on trickle charge so it's all good. On a side note t.here is a maintenance power setting on the control panel, would it be advisable to leave the 220 hookup plugged in over winter?

Most modern vehicle will have some electronics in standby e.g. integrated headunits, central locking, body computers that control can bus, timings for interior lights etc. They shouldn't be flattening the battery in a month though. If you have that kind of parasitic draw its usually something amiss - dodgy old headunits, dodgy old alarms / immobilisers, fuse box corrosion, fused/stuck relay, bad alternator etc. if pulling the fuses doesn't find it next step is disconnect the alternator.

rustynutz

rustynutz wrote: »

On a side note t.here is a maintenance power setting on the control panel, would it be advisable to leave the 220 hookup plugged in over winter?

Yes if it's worth it's salt (temperature compensating, load support with float charge rate = discharge rate @13.6V). No if the charger is constant current.

It's more cost effective use a little solar panel like a 15W than running a mains cable and a powering the charger 24/7 because they're real inefficient at float.

You could fit a disconnect between the Habitation battery and the domestic loads for when you're dry docked this would remove non-essential drains.



This type is a rare breed of DIN Rail Mount, HRC Fused, High DC Current Disconnect/Isolator.
Most cheap isolators you find aren't rated for on-load disconnecting. Isolators are only to be switched when the system is powered down or as close to it as possible.
Depending on setup you may want a solar charger and battery monitors upstream of the isolator.

While I like Isolators, it might be a bittova band aid of a solution. Really the fix is new batteries and address the ghost load.

Your current batteries are hooped by the sound of it. New lead time..