Buying a Smartgauge

[Dockhead]

Originally Posted by a64pilot

Primary for me is Solar, secondary the generator.
Balmar 614 is a good piece of kit, but a good shorepower Charger is superior in my opinion.
However now with an AC watermaker, I can also make water if we are motoring off of the inverter and the alternator has enough oomph to keep the batteries up, saves running the generator.
However it doesn’t bother me a bit when sailing to crank the engine and bump it to 1200 RPM or so to charge, and with the Autoprop I get some drive off of it to. It when I’m motoring and engine is above 1500 RPM or so that it bothers me, just too loud.
I say I have a love hate relationship with my engine. I love how reliable and dependable it is, just hate running the thing.

Why, is it noisy in your boat?

I love to sail (kind of the point), and keep the motor off as much as I can, but I love my diesel engine too. Love the way it sounds (I only don't love the way it smokes). Doesn't bother me at all to use it -- I love diesel engines and machinery, and I just become a motor boat when needed.

I guess how you feel about this will influence a lot how you feel about using an alternator to charge. But love 'em or hate 'em, everyone but the Pardeys and maybe a very small number of small cruisers who mostly use their motors to get in and out of port, almost all of us motor roughly as much as we sail, in terms of miles done, and many of us motor more miles than we sail.

So the alternator can be a really useful charge source, and on many boats might be the main one. It really pays to have a proper large frame alternator designed specifically for bulk power production, if you can fit it. On passage, with the Autoprop, if you're not heeling too much, say in calm weather, you can put on the main engine at low speed, and pick up a knot or two of boat speed, and charge at the same time. This is really handy. A couple of hours at 25%C will get you from 50% to 90% just like that, and you're good for another day or so of sailing, on my boat anyway -- on my boat it's faster than using the generator and battery charger (which at 70 amps is about 17%C). Do energy intensive chores at the same time, make some hot water, do some electric cooking, etc. I can even run my washer/dryer off my alternator -- and I traditionally run a load or two when I doing the Kiel Canal where it is forbidden to shut down the engine.

[conachair]

Originally Posted by Dockhead

So the alternator can be a really useful charge source, and on many boats might be the main one. It really pays to have a proper large frame alternator designed specifically for bulk power production, if you can fit it.

Maybe worth noting that it might not be that great, don't think I've ever seen anything like full output after going for the upgrade 110A option when fitting a new engine. Then I try not to go too low SOC on the batts.

This is based around AGM, might be worse for lead acid as they don't accept such high charge as AGM I think -
How Fast Can an AGM Battery Be Charged..? Photo Gallery by Compass Marine How To at pbase.com

12 minutes gained with twice the power.

[john61ct]

Originally Posted by conachair

Maybe worth noting that it might not be that great, don't think I've ever seen anything like full output after going for the upgrade 110A option when fitting a new engine. Then I try not to go too low SOC on the batts.

This is based around AGM, might be worse for lead acid as they don't accept such high charge as AGM I think -
How Fast Can an AGM Battery Be Charged..? Photo Gallery by Compass Marine How To at pbase.com

12 minutes gained with twice the power.

Yet another problem that completely disappears using LFP! But then you really do need a cool and robust alt/vr setup with scalable derating.

[a64pilot]

Originally Posted by Dockhead

Why, is it noisy in your boat?

I love to sail (kind of the point), and keep the motor off as much as I can, but I love my diesel engine too. Love the way it sounds (I only don't love the way it smokes). Doesn't bother me at all to use it -- I love diesel engines and machinery, and I just become a motor boat when needed.

I guess how you feel about this will influence a lot how you feel about using an alternator to charge. But love 'em or hate 'em, everyone but the Pardeys and maybe a very small number of small cruisers who mostly use their motors to get in and out of port, almost all of us motor roughly as much as we sail, in terms of miles done, and many of us motor more miles than we sail.

So the alternator can be a really useful charge source, and on many boats might be the main one. It really pays to have a proper large frame alternator designed specifically for bulk power production, if you can fit it. On passage, with the Autoprop, if you're not heeling too much, say in calm weather, you can put on the main engine at low speed, and pick up a knot or two of boat speed, and charge at the same time. This is really handy. A couple of hours at 25%C will get you from 50% to 90% just like that, and you're good for another day or so of sailing, on my boat anyway -- on my boat it's faster than using the generator and battery charger (which at 70 amps is about 17%C). Do energy intensive chores at the same time, make some hot water, do some electric cooking, etc. I can even run my washer/dryer off my alternator -- and I traditionally run a load or two when I doing the Kiel Canal where it is forbidden to shut down the engine.

My boat is small so the engine does not have its own separate room.
It’s Underneath the companionway stairs, sort of in a box. Now three sides of the box are removable so access is outstanding, but yes, the little bugger is loud, and unlike a big ole V8 or V12 in a big powerboat, this little Yanmar is pretty much a lawnmower engine, and sounds like one too. My last lawnmower was a John Deere, it was an M997 with a thirty something HP Yanmar.
Once I get on a nice beam reach sailing, well the boat just feels like it’s doing what it’s supposed to. Now that may sound silly, but my entire life has been maintaining and squeezing the best performance / efficiency out of a machine, and you do get an ability of feeling when an engine is in its sweet spot or an aircraft at its best rate of climb or a bike is right at its traction limit. You go by feel.
7 kts under sail is smooth and quiet and not all that much lean either, about 5 degrees. It and I are happy. Under power its loud, it vibrates, you can feel the prop wash in the helm and the boat just doesn’t feel right.
I motor when I have to, sail when I can. However I bet that the motor is on for way more than 50% of the time. I hope that changes in the trades.

[a64pilot]

Military use of a smart gauge that I know about is in an M1 tank.
One of the Cav mission is a screen line, essentially keeping watch. The M1 uses battery power of course for its thermal sights which it needs at night, now real good Military grade thermals are super good, they are cooled FLIR, and cooled way below what your freezer is capable of. It seems that a super cooled IR detector detects heat so much better than one at room temp or higher, so they use a lot of power.
The turbine engine is super fuel inefficient at idle. Couple that with a battery being low doesn’t mean a turbine engine that won’t start, it means a turbine engine that overtemps during start and that can cost hundreds of thousands of dollars depending on how hot and how long, plus a deadlined tank in Indian territory. So battery monitoring is crucial, and the only thing that worked was apparently the Smart Gauge.
Now it’s my understanding that they now have a small diesel APU, or generator that sips fuel and they run it when sitting but keeping watch with the thermals. Fitting the APU wasn’t as simple as you may think, I don’t think there is much wasted space in an M1.

[rgleason]

Saillegend wrote:
"I hate to tell you but a 15W PV panel will not be anywhere large enough to keep your batteries charged whilst you are using the boat. OK over winter."

Many ways to approah this...We top off the batts with the 15 watts PV. It is not intended to take the major loads! Saves our engine use after 90-95% charged. Works great.