Monday, September 17, 2012

Electrics Sorted!

Ever since we have owned Caxton I havn't been happy with the read-out on the mastervolt panel ... it basically indicated that the batteries were going flat and only registered a charge when the travel-power was on and charging was taking place through the mass combi charger/inverter.  When we were on shore power the batteries quickly charged to 100%.  I knew that in reality that the batteries were not going flat and were being charged, so wanted to get to the bottom of why the panel wasn't registering correctly.

Keith - the Mastervolt guru - works out of Hinckley, so whilst we were on the Ashby I thought it would be a good time for him to come out and check it out ... he had a cursory look last Friday but didn't have his laptop to hook into the system.  He turned up on time today with all the test gear and confirmed that the panel wasn't receiving the correct info. through the shunt.

To make it very simple ... all the power going in and out of the batteries must pass through the shunt, when he checked out the wiring all the positive cables were connected fine but on the negative side only the negative from the charger/inverter was going through the shunt, both the engine block negative and domestic negative cables were going directly to the batteries and bypassing the shunt.  So. yes. it worked and the batteries were charging - but the shunt wasn't relaying the correct info to the monitor panel.

Keith left and I connected the negative cables correctly and 'hey presto' all working correctly!  It now registers the alternator charge without the travel power being turned on, as it should.  We ran for about 5 hours today and the batteries have gone from 65%  to 85%  ... woohoo I'm a happy chappy (so am I ... Elaine !  Can you imagine what a pain in the wotsit he had been with his head in the cupboard at any given opportunity muttering about charges and batteries etc !!!!).

On rereading all that gobbledygook Tom from NB Waiouru would be proud of me!
How the shunt should be wired.
So we finally left Shackerstone after being here for 3 most enjoyable days; it really is a lovely little hamlet with a very nice pub!
Shackerstone Mound
 We passed this boat as we left, could this be the boat for Barry ex NB Northern Pride?!!

Lovely Leicestershire scenery ...
We emptied the very full cassettes at Sutton Wharf and gave Caxton a good drink of water.

We stopped for the night at Stoke Golding - it was a bit late and we were getting very low on supplies so we took the doggies for a walk up to the village, the one shop was shut but the three pubs were open......we only went to one - honest!

Back on the boat I made a 'Paul pasta special' - tuna, pesto, olives and spag, ... I don't think mother enjoyed it that much!

Have I mentioned how happy I am with the Mastervolt system working correctly......  ?
(Have I ? Elaine !)  


  1. OH Electronic Guru you, how I worship thee. Can you come and advise me still talk in tongues....

    1. I reckon I could get to 100% today.....woohoo

  2. Paul
    Glad to read that you have got to the bottom of that little conumdrum and got things sorted. What is a bit perplexing is I understand that it was KEITH who wired all this up on Caxton and also Keith who replaced the initial Shunt under warranty!
    X Lesley

    1. Hi Lesley
      I asked him if he installed the Mastervolt on Caxton, his reply was he didn't think so!
      Annoying thing is that if Mastervolt had a simple wiring schematic like the one he gave me plus mention on their literature that all positive and negative must go through the shunt even I could have figured it out.
      Hope to catch up with you guys soon
      Paul x