boat work

Batteries on Boats

/ Ben Starling / Leave a comment
photo by: Joanna Poe

Last weekend, we attended a lecture at the Cruising Association on ‘Power Systems on Boats’, by Matt Boney. 

We’ve attended a lecture on electrics on boats there before, but it’s always good to hear more on this topic again. Confirms that this is definitely something we need to master. Loads of studying ahead for the Can Opener…

Here are the key highlights from the notes I required the Can Opener take down (Hey Furrball, I’m self-motivated! I do not need you camped on my shoulder, waggling my ears like horse reigns to make me write faster…):

Battery Capacity

  • Most cruisers do not have enough
  • 150amps/day is a small amount
  • You probably need a minimum of 300amp hours at 50% of DoD (depth of discharge)
    • and batteries only top up to 80% of their capacity
    • so you need to actually have more like 420 amp hours to be able to use 300 amp hours/day… and still would have to charge every day
    • AND you don’t want to run your battery to 0… only want to run it down to about 25% of battery capacity
    • therefore you need even more capacity!


Which battery to use?

  • You can mix battery sizes to increase capacity (lifeline tested this) as long as batteries are
    • the same age and
    • the same make
  • With batteries you ‘get what you pay for’… quality costs..

 Types of batteries

  • Sealed leisure or marine batteries 
    • are ‘maintenance-free’, 
    • but can’t be topped up so they won’t last long. 
    • They are also affected by temperature.
  • Gels 
    • are useful, 
    • slow discharge
    • old technology
    • expensive
    • hard to find
  • AGMs
    • are the best (?)
    • becoming more popular
    • make sure you get the right AGM for the right purpose! (There are many potential uses for these…)

Monitoring your batteries
You should 

  • charge your batteries to 100% every month to anti-sulfate them – otherwise they will become permanently sulfated
  • should estimate when you hit 50% DoD by measuring battery voltage
  • must have a panel mounted digital volt meter
  • must have a small digital multi-meter
  • all batteries must have multi-stage regulators
  • test your batteries 2x/year
  • use your alarms!
  • monitor regularly!

Ways to generate electricity?
  • shore power charger
  • solar – recommended 600Watts+ or you won’t be able to replace daily usage
  • wind or towing generators – expensive, but easy and convenient
  • AC or DC diesel generator – DC is the quieter of the two
  • Honda petrol generator – don’t get this one. There are no petrol stations at sea. And you are not really saving a lot on size.
What type of batteries are you using? What kind of generator(s) are you using? Are you getting the voltage you need out of them?
–Captain Cat 
 (transcribed by the Can Opener)

Capable Cruiser – Reviewed

/ Ben Starling / Leave a comment
links below at bottom of post

 

Book the Captain just finished snoozing on: Capable Cruiser

Previously snoozed on: Cost Conscious Cruiser – and loved it
Okay. I love the Pardeys, I’m a big fan. I zipped right through another book in this ‘series’ called Cost Conscious Cruiser. I slept on the cover for a mere 3 afternoon naps and the contents filtered right up into my brain, no problemo.

Their philosophy of simplicity and downsizing spoke to my furry heart. It had large sections that could be described as ‘introduction to lifestyle’ themed. So often not so tough to get through.

CapableCruiser is dense – and that’s good
Have to admit though that I pushed myself at times to get through Capable Cruiser. It’s focus leans more towards seamanship, anchoring and repairs. All of it critical info to know, but denser to absorb.

How to buy a yacht, medical issues, life at sea, getting along with crew are discussed too (these I could get through in a single night’s delightful beauty rest).

While I will probably not buy a boat with a bowsprit, absorbing Larry’s detailed descriptions of the pros and cons and how to add one to your yacht (if you decide to) is important to get through at least once. Ditto the section on tenders, steering failures and repairs at sea.

Conclusion
So I got through it and am glad I did. A good add to the sea library.

I’m handing it over to the Can Opener as required reading and I’ll probably snooze on Capable Cruiser again some time next year.


Got a good recommendation for the sea library?
What books are a must for the cruising life?



–Captain Cat

(transcribed by the Can Opener)

Book Reviews
Next: Self Sufficient Sailor  
Previously: Cost Conscious Cruiser

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