12v tank heater

Cymro, unless your van had been built and stored you should have the EC500 (big grey box with fuses, breakers,etc and the EC480 control panel. Would you mind double checking?

Cymro wrote:Thanks Mojo - but mine is the 328S system. Should that sustain a similar drain when on mains and using the heating pad?

Incidentally, just been to see van having left gas heating on low overnitght - snug inside so dump valve didn't open. Fascinated to see icicles below the outside flue!

Leisure battery coped fine with overnight heating - shows 12.3v this morning.

Pretty cold here in mid-Wales!

Hope to find a signal so as to post this.

Sorry - I got confused by some of the above into thinking that you had an EC500. As Chudders says, the EC328 should have no trouble keeping up either. Perhaps the charger supply had somehow got directed to the vehicle battery, but it should still have disconnected the habitation load well before the leisure battery dropped to 2.5V! So there still appears to be something at fault there...

[Edit: cross-posted with Peter there - it would be interesting to know which Sargent panel you have - the only relevant difference to this problem would seem to be the intelligent charger load-sharing on the EC500, which the EC328 does not have.]

Just checked handbook and it could be either!!! I thought they had stopped using the EC328 circa 2013.

Peter Brown wrote:Just checked handbook and it could be either!!! I thought they had stopped using the EC328 circa 2013.

I'm also puzzled by the reference to EC328S. I can recall some issues when my 328 was accidentally (ahem...) set to run EC328S settings - could that be related? I can't check as my van is in at the dealer's for steering column replacement at the moment...

If it is a 328 you can charge either battery from the mains but not both together.

I'm guessing the tank pad is wired direct to the leisure battery and not via the Sargent unit so that the heater works if the control panel is switched off.

The circumstances Cymro described would occur if the panel was switched to charge the vehicle battery, switched the heat pad on and it got cold. The pad would be taking 4Ah every hour with nothing being put back.

EC500 shows fuse for tank heaters, EC328 doesn't

Peter Brown wrote:The pad would be taking 4Ah every hour with nothing being put back.

But the EC328 should still chop power to the habitation side at 9V, even with no charger power going to the leisure battery. I would still like to know about the reference to EC328S, though...

Not if tank heater bypasses 328

Nuevo at NEC today has EC328 and tank blanket wired direct to leisure battery.

Peter Brown wrote:Nuevo at NEC today has EC328 and tank blanket wired direct to leisure battery.

Am I being unduly negative in suggesting that it's connected like that because it's a damn sight easier to do it that way, rather than to unship the connector from the underside of the EC328 and do it properly with the correct terminals in the multi-way connector? I can't think of any other rational explanation, when the voltage monitoring of the EC328 seems the obvious way to protect the leisure battery from excessive discharge...

I have decided that I will fit a 12 volt tank heater and insulate the exposed pipes wherever I can get at them. Do you think the domestic split pipe lagging will do the job I wonder. However I have never gone anywhere in 5 years without an electric hookup inc. home in any of my 3 vans. (don' do wild camping thingy) I am going to run it off the mains electric via a 12 volt regulated supply and fit an appropriately located switch with indicator so it will have no effect on the battery.
A little job during the coming warmer months I am hoping.

Mojo, I don't think there is sufficient capacity left on any of the 328 fuses. There is a dedicated circuit provided for the tank heater in the EC500.

Peter Brown wrote:Mojo, I don't think there is sufficient capacity left on any of the 328 fuses. There is a dedicated circuit provided for the tank heater in the EC500.

There are 12 individually fused outlets on 15-way connector D with power ratings in the range 5-20A, but you may be right for Cymro's van. There are ~lots~ of spare circuits on the Celex, but then it's a much simpler van...