[C320-list] Starter Battery and Echo Charger

[Graeme Clark]

A few years ago I used a proper ammeter to measure the power drawn by various boat systems. (this was a 1996 model #303)

Obviously individual differences in kit fitted will affect this but its a good guide:-

So, working down from most power hungry to least (figures have been rounded to a sensible significant figure)

Mikuni Heater when starting		18.0Amps
Fridge - when actually running	6.0 Amps
VHF radio when transmit Hi pwr	5.0
Mikuni Heater running on Hi		3.8
Water pump, when pumping		2.0
Autohelm when motor is running	2.0
Mikuni Heater running on Low	1.9
Running (nav) lights			1.6 
Galley downlights (x2)			1.6
Instruments and e7plotter		1.2
Each lamp in Aft Cabin			1.0
Each lamp in Fwd Cabin			1.0
VHF radio when transmit Low		1.0
Gas Valve when open			0.8
Galley strip light				0.7
CD Player/Radio				0.8
Anchor light					0.8
Inverter when charging phone	0.7
VHF radio on standby/receive		0.6
Instruments without e7			0.6
Inverter with nothing in it			0.4
Saloon o/hd double light			0.2
Saloon surrounding 4 lights		0.4
Deck light					0.4
Steaming light					0.3
Everything switched off			0.2


Since then I have changed boats (#366, still 1996 though!) and have just fitted a new fridge to it as well as having changed all lamps (interior and navigation etc) to LED

I have a 100W (nominal) solar panel fitted on the sliding hatch cover in front of the traveller. This is not the best position as it is often part -shaded and being flat is not the best angle to the sun so we never get anywhere near the theoretical peak current (100/12.4) of approx 8Amps but I can get 3.5-3.9amps if everything is perfect, more usually somewhere closer to 2Amps but the best thing is that theres always a trickle from dawn to dusk!

Like you I had 2 x 190 Ah batteries, wired as per the factory build. Like you I was concerned about over depletion and starting.

So the first thing I would say is look to reduce your usage rather than increase the capacity (LED’s etc).  My new fridge draws only 3 Amps.

Whilst I like the idea of  dedicated start battery, the reality is that a flat battery had been a fear rather than a reality. I decided that rather than go to the effort and expense of a dedicated start battery I would simply carry a small stand-alone starter pack (like these https://amzn.to/3ivBfIH <https://amzn.to/3ivBfIH>)

My current boat also had a battery monitor fitted by the previous owner. This doesn't show battery capacity but does show the current being drawn  by (or charged back 
into) the battery at any time.

Finally, as I only have the one solar panel, it is connected to Battery 1.  I then have a voltage sensing relay that connects 1 to 2. So when 1 is charged up the current “spills over” into 2.

We keep our boat on a mooring buoy so unless we visit a marina it is never connected to shore power. The solar panel is great for when we are not onboard as we always start our trip with fully charged batteries.

There are now only two “events’ that will cause depletion of the batteries to a level where I think it is prudent to run the engine for a bit; 1) Extended sailing with the autohelm engaged (new boat has a below deck linear pilot, which I suspect id a bit more power hungry) or extended use of the fridge on warm and cloudy days. I only fitted the new fridge last week, so have yet to see how the more efficient unit holds up.

Obviously if you want to go the starter battery route thats a personal choice. I am merely pointing out that there are other options

Hope this helps

Graeme



> 1.  What kind and size of starter battery do you recommend. Where did you put it?
> 2.  What kind of echo charger do you recommend.
> 3.  My 20 yr old Adler Barber refrigerator compressor is drawing 5.5amps at a setting of 4-5.  Does that seem reasonable?  I’m wondering if the compressor is starting to fail.  It works great and I always have ice but I have no idea how long they usually last.
> 4.  I’m also thinking of getting a solar panel I can throw on the deck to help with battery charging at anchor.  Does anyone do this?
> 
> This stuff is still smoke-and-mirrors to me so I appreciate the input.  Finally, my last post was about the installation of my Raymarine autopilot. Thanks to Jack Brennan’s advice and instructions it’s up and running!  I even replaced the steering cable while I had it all torn apart.  Whew!!!  
> Sara 
> Wandering Star 
> 2000/#707
> 
> Sent from my iPad