450: Battery charging by engine

[a64pilot]

Originally Posted by Simi 60

You dummy Simi

There's green coolant circulating through the motor so a minute or two before the raw water cooling kicks in will be fine.

No, your no dummy, exhaust is HOT, I wouldn’t want uncooled exhaust flowing through my rubber hose and fiberglass muffler for a minute, over time I think it would be bad on it.

[Simi 60]

Originally Posted by a64pilot

No, your no dummy, exhaust is HOT, I wouldn’t want uncooled exhaust flowing through my rubber hose and fiberglass muffler for a minute, over time I think it would be bad on it.

Good point, genset has plastic vetus muffler so even worse.

[Simi 60]

Originally Posted by a64pilot

Assuming your generator comes on line automatically, that one minute is the relay box, it’s purpose is of course to prevent you backfeeding power back into the shorepower connection, so the Boat can only be connected to either the shorepower cable or the generator, not both. .

We have manual start and a big switch in the main panel with genset - off - shore power.
Start key is several steps from that switch so its usual genset start, several seconds to switch and then 30 seconds or so before + amps start showing on gauges.

[foggysail]

Originally Posted by a64pilot

Yes you can charger very effectively with your main engine, as effective as your generator.
IF you have good externally regulated alternators and a good three stage regulator.
Likely you have I assume stock alternators and are internally regulated, if so then no, you can’t effectively charge your batteries. You can maintain a charge, but not a whole lot of real charging will occur as they are not I’m sure putting out absorption voltage.

Yes, a regulator is required to have continuous high current output from an automotive alternator. But again, there are buts...

Alternator armatures are wound with copper wire which will generate heat as current flows in it due to the DC resistance of the wire. And by the way, alternators are 3 phase machines, so the innards make AC currents which can have relatively high frequencies depending on the RPMs. Those currents pass through a three phase, full wave rectifier which is needed to convert the AC to DC output.

Beside the so called DC resistance, the problem gets worst with AC due to what is called skin effect which I will leave to the reader to get a better understanding on his own. But what skin effect essentially does is to force the currents to flow on the outer surface of the wire and not uniformly through the wire. Result... higher resistance which means higher losses in watts.

Now things really don't get better, they get worse. Copper has a positive temperature coefficient which means the hotter it gets, the higher the resistance which means higher losses which means the wire gets hotter.

It is possible to have thermal runaway in an alternator with high continuous output currents. High continuous currents absolutely require the alternator to have external cooling by some means.

[a64pilot]

Originally Posted by Simi 60

We have manual start and a big switch in the main panel with genset - off - shore power.

Start key is several steps from that switch so its usual genset start, several seconds to switch and then 30 seconds or so before + amps start showing on gauges.

Then you have me.
I’d start by taking my multimeter and measuring the output directly at the gen output, to see if it’s delayed. The delay may obviously be controlled by the generator voltage regulator, your manual may tell you if it’s adjustable or not.
Is your generator in a sound shield? If so I assume it has a cooling fan, is this an AC fan? If so then you ought to be able to tap into its supply to run a pump.
There are of course DC pumps, just I don’t know of any that are as reliable as the March magnetic coupled AC pump meant for air conditioners, they run continuously for years it seems.

[Simi 60]

Originally Posted by a64pilot

Then you have me.
I’d start by taking my multimeter and measuring the output directly at the gen output, to see if it’s delayed. The delay may obviously be controlled by the generator voltage regulator, your manual may tell you if it’s adjustable or not.
Is your generator in a sound shield? If so I assume it has a cooling fan, is this an AC fan? If so then you ought to be able to tap into its supply to run a pump.
There are of course DC pumps, just I don’t know of any that are as reliable as the March magnetic coupled AC pump meant for air conditioners, they run continuously for years it seems.

Definitely a delay, like I said, nothing happens until I flick the switch and then 30 seconds later revs drop and load comes on from the charger.

No manual - Diecon engineering build Kubota based.
No sound shield as in the engine room

240v power points nearby so probably no reason it couldn't simply run off inverter and batteries like everything else onboard does.
Could you have something as simple as a switch for the pump wired into the ignition so when the key is on pump is on, key off genset off pump off?

[a64pilot]

Originally Posted by Simi 60

.

Could you have something as simple as a switch for the pump wired into the ignition so when the key is on pump is on, key off genset off pump off?

You could, but I would want to do it like a Hobbs meter. They usually use a normally open pressure switch connected to the oil pressure gallery. It takes oil pressure to close the switch and power the Pump. That way the pump will not operate unless there is oil pressure. I’d want it so that it can’t be screwed up, all it takes of course is to flood the motor once and you can bend connecting rods etc.
Switches like this are also referred to as “Murphy”switches, you can see why.

[warren460]

This is all very interesting. Rephrasing my question, should the alternators ,if properly regulated bulk charge the agm batteries at around 14.6v?.

The discussion re lift pumps and solar are merely noise and have nothing to do with the question. But thank you for you input anyway.

[rom]

Originally Posted by warren460

This is all very interesting. Rephrasing my question, should the alternators ,if properly regulated bulk charge the agm batteries at around 14.6v?.

Isn't it written on your battery ? If it is not then you may find the answer downloading the datasheet from the manufacturer.

[Paul L]

Originally Posted by warren460

This is all very interesting. Rephrasing my question, should the alternators ,if properly regulated bulk charge the agm batteries at around 14.6v?.

The discussion re lift pumps and solar are merely noise and have nothing to do with the question. But thank you for you input anyway.

No. The bulk charge is pushing in as much amps as the charger can deliver.
this starts out with lower voltage. As the battery charge state goes up the number of amps it can.take decreases and the charge voltage increases. The battery charger will then change from bulk charging to absorption. This is where the voltage will be kept by the charger at the mid 14's v till the charger eventually goes to float mode. The actual absorption voltage setting is manufacturer dependent and temperature adjusted.

[rom]

Originally Posted by rom

Isn't it written on your battery ? If it is not then you may find the answer downloading the datasheet from the manufacturer.

oh I guess I misunderstood your question, ignore that. ... what Paul L said then.

[Krabimike]

Originally Posted by Bean Counter

Re Generator impellers for L450. We just took the impeller out. The lift pump (in the bilge) that goes on when you prime or start the generator has sufficient water flow without needing the impeller on the engine, done 1000 hours so far this way. No need to reconfigure anything.

For check valves that get clogged we inserted a spin on transparent strainer between the through hull inlet and the check valve.

hmmm I have wondered if I could just run it without the impeller. I would love to see a photo of your spin on transparent strainer between the through hull inlet and the check valve.
thanks

[Bean Counter]

Originally Posted by Krabimike

hmmm I have wondered if I could just run it without the impeller. I would love to see a photo of your spin on transparent strainer between the through hull inlet and the check valve.
thanks

Strainer pic attached.

You have to make sure raw pump is properly primed. If Gennie shuts down with the 7 flash signal (raw water pressure) it is usually a prime issue. I hold the prime button down on gennie for 5 seconds, let it sit for 5 seconds, then prime again for 5 seconds, let it sit 5 seconds, then start. The alternate is to fill the strainer at the engine and let it drain back down to the pump.

On further point, the raw water pressure sensor on entry to the heat exchanger can malfunction, ours did at 2200 hrs and needed a new one. Difficult to get at.

As a test. Take the impeller out and put lid back on engine pump. Press prime button and watch water surge inside the vetus strainer. Start the engine and watch water eject from exhaust out of hull. There are two protection mechanisms the raw water pressure switch and the exhaust heat at the elbow.

This assumes your later model boat is set up the same way as a 2011 F

[Krabimike]

Originally Posted by Bean Counter

Strainer pic attached.

You have to make sure raw pump is properly primed. If Gennie shuts down with the 7 flash signal (raw water pressure) it is usually a prime issue. I hold the prime button down on gennie for 5 seconds, let it sit for 5 seconds, then prime again for 5 seconds, let it sit 5 seconds, then start. The alternate is to fill the strainer at the engine and let it drain back down to the pump.

On further point, the raw water pressure sensor on entry to the heat exchanger can malfunction, ours did at 2200 hrs and needed a new one. Difficult to get at.

As a test. Take the impeller out and put lid back on engine pump. Press prime button and watch water surge inside the vetus strainer. Start the engine and watch water eject from exhaust out of hull. There are two protection mechanisms the raw water pressure switch and the exhaust heat at the elbow.

This assumes your later model boat is set up the same way as a 2011 F

Thanks! I will give it a go!

[smac999]

Originally Posted by warren460

This is all very interesting. Rephrasing my question, should the alternators ,if properly regulated bulk charge the agm batteries at around 14.6v?.

The discussion re lift pumps and solar are merely noise and have nothing to do with the question. But thank you for you input anyway.

you can't bulk charge at 14.6v it will absorb charge at 14.6.

at bulk it will struggle to to get as high as it can. this depends how big the alternator is, how big the bank is, and how low it is.

on a small alt and big bank, you might be bulk charging at 13v. hours later it'll be at 13.5, hours later 14. hours later 14.5v, then you are absorb charing at 14.6. the alt is maxed out amp wise and is struggling to hit the absorb voltage

if you have a huge alt and small bank. it might bulk for 20 mins and you'll be at 14.6 aborb charging very quickly.