Charging batteries when on anchor

[Oceansailor]

Originally Posted by senormechanico

There is also the forest fire smoke in Canada.
With 560 watts of solar, we need to balance our vacation time around it.
If we're lucky, we're fat and happy with a ton of power.

We even use the inverter to make hot water after using the Spectra to make it.
Too early, lots of rain and no solar to speak of.
Too late, lots of smoke and no solar to speak of.

Kind of surprised to hear that you had that much smoke from the wildfires that it affected your solar. I’m always positively surprised how much charge I get from solar on a sunny day with very light clouds/haze. I guess that is because of the absence of shadows?

[senormechanico]

The sun was not orange, it was red. Sometimes, even DARK red.

The days got cold.

This photo was shot in August at noon. That is smoke.

The swimming lake even noticeably cooled off after about a week.

[petter5]

My friend have a 30 Ft motor boat with a new diesel engine and a decent alernator and new batteries. Leaving the harbour for the weekend and going a trip to islands neare bye for the weekend, his batterier was always "bankrupt" before sunday afternoon, mostly due to the refigerator running keeping his food and beverage cold. He then decided to install a modest solar panel, and since that day hed could just forget the batteries and high idle running for charging. The conclusion is that a solar panel might be the best solution and should be considered before other options for your power problem.

[kas_1611]

Originally Posted by petter5

his batterier was always "bankrupt" before sunday afternoon, mostly due to the refigerator running keeping his food and beverage cold.

Insulate the fridge so it doesn't need to run all the time. I added 10mm of EVA foam and a layer of metallic "bubble wrap" inside my fridge and lined the outside, where I could reach, with the same and I use about an amp per hour to keep the fridge between 0ºC and 8ºC (air temp, water temp is less variable). Without the insulation the compressor was running almost constantly.

Sometimes reducing the load is as important as finding ways to add charge. Incandescent light bulbs and halogens are real vampires so if you haven't already done so ditch them for LEDs.

[john61ct]

Reflectix and similar mylar+bubble wrap are completely useless in that scenario, ineffective in any mobile context, no insulation value whatsoever, just wasting space.

Yes the intention is good, a fridge powered off alternative energy should have at least 2-3" inches of **effective** insulation, 4+ even better.

[kas_1611]

Originally Posted by john61ct

Reflectix and similar mylar+bubble wrap are completely useless in that scenario, ineffective in any mobile context, no insulation value whatsoever, just wasting space.

Yes the intention is good, a fridge powered off alternative energy should have at least 2-3" inches of **effective** insulation, 4+ even better.

I disagree, the silver bubble wrap reflects the heat from the compressor and prevents it rising up into my fridge. I've checked with an IR thermometer and there is a marked difference. The air trapped in the bubbles acts the same way as every other form of insulation, including snow, by reducing or eliminating convection.

As for putting 100mm of insulation around my fridge well that is impossible due to baulkheads and design, unless I want to fill my fridge with insulation which kind of completely defeats the point.

Hell even 20mm of aluminium foil wrapped corrugated cardboard had a dramatic improvement in the insulation of my fridge when I first used that under the base.

[john61ct]

Ah sorry, I thought you were talking about insulation, as in slowing the conductive transfer of heat

Yes, any shiny metallic surface will reflect / redirect radiating heat, which is an entirely different subject.

Improving air circulation to keep the condenser and electronics cool will also improve both efficiency and effectiveness of the system.

[svspirited]

Now that was an informed read, thanks for posting that.

Originally Posted by a64pilot

Found it.
https://apps.dtic.mil/dtic/tr/fulltext/u2/a151273.pdf

[lewisa]

I regularly charge my batteries at anchor with my Perkins 4-108 running at about 1200-1300 RPM I've been doing this since installing the engine in 1990 and have never had a problem with the engine. As others have suggested, as long as the engine is regularly run at cruising RPM's as well, there seems to be no issues.

[sailorman14]

New 200watt solar panels are less than $200. If you can make room that’s the way to go. They will charge for 12+ hours a day every day.

[Jim Cate]

A64,thanks for posting that dreary but very informative report. It supports what lots of folks have been saying... high idle low load running isn't really the kiss of death. Good to have an objective analysis of the subject.

One thing stood out for me: we are often told how awful high temps in the engine box/room are, but here they are saying that warmer intake air is a really GOOD thing! Maybe my rather small volume engine box and consequent warm to hot intake air is why my engine is in such good nick with >5k hours and considerable low load running. I think that I'll dump my plans for bettering the ventilation there!

Thanks again... that report may be a bit dated, but then so are the engines we mostly run! (And our bodies too!)

Jim

[sailinglegend]

Originally Posted by a64pilot

Just read the Cox article, he is completely wrong on bore polishing....Now I hear that synthetic oils will cause bore polishing?

Rubbish.....

I think 'RUBBISH' this is classed as 'being rude' and under Forums rules should be reported to the Moderators - so you'd better pick this one up yourself!!!!

I have just spoken with Vyv Cox whose boat is on the same pontoon as ours on a Greek Mediterranean Island. He just laughed when I quoted your response to his article. So I asked him for a quote:

I worked for Shell Oil for 30 years specialising in oil products and the problems of Glassing and Polishing.

That was 30 years of cutting up engines to see what affect different oils have.

Originally Posted by a64pilot

There are so many engine experts out there, that post articles and have followings I’m not sure what to say.....

Then don't say anything!!!!!!

Or simply tell us what makes you such an 'expert' on marine diesel engines - not aircraft jet engines?

[sparty]

Originally Posted by john61ct

So can you rig an adjustable Open setpoint, to let it get to a higher temp, when you know that's needed?

To my knowledge, you cannot adjust a thermostat. However, you can purchase thermostats with various temp settings. If your engine constantly runs cold, you could install a higher temp thermostat.

[wingssail]

Originally Posted by Oceansailor

Occasionally I have to run the engine for charge at anchor. Normally I run the engine @ 1900 RPM and get about 150A.

I do run the engine quite hard afterwards in order to burn out carbon deposits.

I’m looking at a new alternator as the old one have over 2000 hours.

Would it be a significant improvement (less carbon build up) I could manage the charge at lower RBM. Let’s say 1300-1500 RPM?

Not that it means anything, but we have been charging the batteries daily with the main engine for 26 years at 2000rpm, (not all days in those 26 years because much of the time we have been in marinas where shore power is available) and we have 6300 hours on the engine, most of it has been charging batteries because we usually sail when underway, not motoring, so these are primarily charging hours. We have had more than one alternator over the years but mostly 110 amp Balmar units, single belt, small pully.

We rarely run the engine hard by motoring or otherwise, but do occasionally to see how it acts.

After all of this usage we never had any observable engine problems such as oil usage or smoking. None. And no significant engine repairs or rebuilds.

So our conclusion is that this usage pattern is OK.

[geoff3nebel]

Nigel Calder has written in great detail on this subject. Check him out on Google.