Restistance is Useless - Bothersome Batteries

It's not been 6 months since we replaced our batteries, so waking up to discover that the Bloke had been up half the night supervising the battery consumption and eventually switching off the fridge and freezer, was something of a surprise. What the heck was going on? Apart from the fact that the batteries are so young, we'd also been scrupulous in not letting them fully discharge; in fact rarely letting a day pass without some form of charging 'top-up' over and above the solar panel input. We were perplexed. In the previous 36 hours we'd run the 'gennie' for several hours; motored off and on for at least 5 hours; had plenty of sunshine, PLUS, when we called into the marina to top up water, we seized the opportunity to hook into shore-power for at least 6 hours before setting off for the run up the coast from Middle Harbour to Pittwater. To be sure, running all the nav gear while sailing (+autohelm, VHF radio etc) will chew some amps up but this trip was of merely 2-3 hours duration. We thought we were fully charged before we left and somehow overnight we'd gone from seemingly fully charged to not. Only the fridge and freezer were on duty while we slept. Where did the amps go?

The fridge is our own version of the 'canary in the mine' as a tell-tale indicator of low voltages. The compressor won't kick in. Then the situation gets worse because in attempting to kick in, it draws yet more amps and because the fridge is meantime warming up, the thermostat keeps triggering the compressor. More amps are sucked from the batteries and before long the food's getting hot and my 'Amp Nazi' skipper is also in meltdown.

     

The Creeks are no longer empty at this time of year. 

The Bloke made sure we'd have company for 5'ers.

Thoughts of a nice 3 day stay in the gorgeous Smiths Creek were shattered after only a single night. We had to head into a Marina; access some 240v shore-power, get a phone and internet signal and not necessarily in that order. The Bloke, already cranky from sleep deprivation, now had an intellectual problem too and barked instructions to contact a nearby marina; PRONTO!

In recent weeks we've stayed on a swing mooring owned by the D'Albora Spit Marina. When ashore to use the showers, we've been listening to promotional messages piped into the bathrooms. "D'Albora Marina's..... Blah, blah blah". The endless and daily repetition of these messages kicked in.... The Akuna Bay Marina in Coal and Candle Creek, the one adjacent to Smiths Creek and therefore not far from where we were, is also a D'Albora Marina and as such, we were allowed to 'visit' under a reciprocity arrangement. Brilliant. There would be no need to exit the Creeks. A phone call was greeted most welcomingly and enthusiastically. ".. No problem. Come straight in. We have electricians on hand. We'll find you a pen. Just pull up at the fuel wharf and contact me on the courtesy phone. We'll have it all organised by the time you get here". WOW! Our day just got better in an instant! Assisted by not 1, but by 3 Marina staff, we were alongside and connected to shore power in no time.

Step 1: We would need the batteries to be 'fully and deeply recharged' before they could be checked by an electrician. The Bloke called Battery World Caringbah to discuss our issue as it was potentially a warranty matter. They were hugely helpful and reassuring and provided plenty of additional information, but first things first, the batteries would need charging and testing and we'd need to be alongside for a minimum of a day. In the end we stayed 2!

Step 2: The Marina electrician verified that the batteries were in top condition. Great news. So what was the explanation for the apparent fridge failure?

Step 3: Open all the tool boxes and especially the F@€k  box.

Step 4: The usual - tear the boat to bits!

 

Step 4 accomplished.

     

A cabling upgrade in progress.

6mm to 10mm wire from thermostat to compressor and across to bus board.

This story has a happy ending. Still heeding the doctor's directive to "avoid playing golf and tennis", the Bloke contributed to his speedy post-operative recovery (not) by proceeding to do the usual boat-repair-contortions in 40C heat. The loss in voltage needed to be traced and like a water diviner, the Bloke probed every connection in the 'refrigeration' cabling with the 2 prongs of his amp meter. "Resistance is useless!" being his mantra! There was a small voltage drop from one end of the cabling to the compressor junction, so a purchase of some heavier gauge 10mm cable as an upgrade to the existing 6mm one, provided all the occupation a fellow could want for the following 4 hours. this would reduce electrical resistance and potentially maintain the voltage across the electrical run from the bus to the compressor.

Inevitably, what was his job also became my job since I was required to shine the torch, pass tools and 'not' pass comment!  Eventually my smaller hands and thinner fingers were more useful in some instances that brute force and the entire contents of the F*@K box. The job was completed and the Bloke's reward was some end of day drinkies aboard a neighbouring boat.

 Just back from Noumea, the owners of MV Karajas hosted us on their gorgeous Nordhavn.

Moonrise signalling the conclusion of a VERY long day.

Post script: So far, so good. The new cabling has made a BIG difference and Battery World Caringbah provided fabulous back-up and a new table for assessing residual battery capacity. Golden!