Battery trouble, so I ran an experiment.

[skipmac]

Originally Posted by nigelmercier

Huh? Some confusion I think.

Ignoring conversion losses, Watts vs volt-amps, power factor, the generator's actual output, etc the basic math is correct. 13 amps at 120 V is about 1560 Watts. 1560 Watts of power at 12V gives 130 amps.

[oleman]

I get better results when I isolate paralleled batteries so there is less load on the charger when the batts are totally discharged.
Using a real 40A multistage charger, I run the charger until the charger is happy or for about 24 hours, after that go to the next battery and tri again later.
I run our old Detroit Diesel work boat with a series pair of Trojan golf cart batteries, since they are 6V I have to charge them in series on the malfunction 12V charger that is limited to 40A, it has taken as long as 36 hours to get a happy charger, if the batts are totally discharged.
The Trojans are fine batteries but consume distilled water the way a Detroit Diesel 2 stroke consumes oil.

[vmattiola]

Sounds like solar panels for the win. Will definitely be going that route for long term storage on mooring ball.

Another question:

My engine alternator feeds to it's own controller then to battery banks via 12V side of things (duh).

My Honda generator feeds into my A/C circuit at 120V on it's own charger, then to battery banks.

Can I (slash should I) run both together to try and cut down on charging time?

I liveaboard and work ashore so the only feasible time for me to do a really long charge cycle of 10+ hours is overnight while I sleep. I obviously don't want to leave the motor running while I'm ashore.

I think tonight I'll do a LONG charge and in the morning monitor the drain of power as I load up the system. I'll also disconnect each battery and test independently on voltage holding capacity.

[Maine Sail]

Originally Posted by vmattiola

Sounds like solar panels for the win. Will definitely be going that route for long term storage on mooring ball.

Another question:

My engine alternator feeds to it's own controller then to battery banks via 12V side of things (duh).

My Honda generator feeds into my A/C circuit at 120V on it's own charger, then to battery banks.

Can I (slash should I) run both together to try and cut down on charging time?

I liveaboard and work ashore so the only feasible time for me to do a really long charge cycle of 10+ hours is overnight while I sleep. I obviously don't want to leave the motor running while I'm ashore.

I think tonight I'll do a LONG charge and in the morning monitor the drain of power as I load up the system. I'll also disconnect each battery and test independently on voltage holding capacity.

First off you should not let your battery voltage drop below 12.2V even when monitored while under your average house loads loads. If you do this, charge regularly, and add solar you will be in a much better situation. If you do this you can occasionally dip to 12.15V or even 12.1V on occasion but not lower..

You have not been clear on how big (how many amps) your 120V charger is?

Unfortunately your batteries are likely toast having suffered the battery equivalent of the Texas Chainsaw Massacre. A battery taken below 11.7V with no large load will not last long at all.

This is murder...

Originally Posted by vmattiola

*ALL lights, fridge, instruments, water pump, sink pump, bilge pump ON*
0 12.04
2 11.84
4 11.79
7 11.68
9 11.49
30 11.26
47 10.83
60 10.05

You should have stopped discharging & began charging well before you were at 12.04V...

12.73V 100%
12.2V Start Charging
12.1V Murders Abuse Begins

[hellosailor]

There are also devices with names like 'Battery Brain'. Not expensive compared to the price of a battery. A bad idea only because "more stuff" means more stuff that can break.


However, they are designed to save batteries. When the battery voltage drops to a preset level, still high enough to start an engine but below any normal voltage, the "brain" opens up a relay and disconnects the battery.


There are marine versions, and versions with a remote control fob, but the plain and simple kind are basically like circuit breakers, just push a reset button and your battery is connected again. And hopefully still has enough power to start something else, and not be damaged by going dead.


OTOH, some folks would rather find a dead or near dead battery and know the bilge pump got every last chance to try saving the boat. "More stuff".

[MarkJ]

Originally Posted by vmattiola

Should I just go for 24hrs of charge and let the smart charger do it's thing?

Essentially yes. Don't make it too complicated.

I am in St Martin too so if you want to have a chat VHF#10 Sea Life.

Mark



Sent from a stupid phone that replaces words with weird stuff.

[btrayfors]

Originally Posted by skipmac

Ignoring conversion losses, Watts vs volt-amps, power factor, the generator's actual output, etc the basic math is correct. 13 amps at 120 V is about 1560 Watts. 1560 Watts of power at 12V gives 130 amps.

Yeah, yeah, but that's all misleading for this OP.

He has a Honda EU2000i generator. This generator, at a maximum, will put out enough 120VAC current to power a 120VAC-to-12VDC external charger of about 80amps. It will not run a 100A charger or more, at least not flat out.

So, if he had a suitalbe charger for that Honda generator -- say an Iota DLS-75-IQ4, he'd be good to go in the mechanically run charging department. Anything less powerful would be wasting the generator's capability. Anything more than 75-80A output simply wouldn't run.

Of course, the 100A alternator on the main engine is the primary charging source, if properly regulated. One assumes he has an external, maybe programmable regulator, like the Balmar MC-612 or MC-614. If so, he's good to go if he sets that up properly.

I'd dump the batteries -- all of them -- and start anew, with all the same make and model flooded, gelled, or agm batteries. In that order of preference. A good even smallish solar panel & MPPT regulator would top off the electrical charging setup and keep the new batteries happy.

IMHO, it's not worth it fooling around with the existing batteries. Bite the bullet, get the right setup, and go sailing.

Bill

[socaldmax]

Originally Posted by Adelie

40a at 12v is 480w. even with 50% efficiency loss in the charger the EU1000 should still be able to cope just fine.


A house is but a boat so poorly built and so firmly run aground you would never try to refloat it.

Battery chargers don't put out 12v. They should be putting out at least 14.4v or they really aren't charging the battery. That's actually 14.4 x 40 = 576 watts, assuming 50% efficiency, that would be 1152 watts, continuous.

Even if it only put out 12v, 480w x 2(50% efficient) = 960 watts. The 1000 only puts out 900 watts continuous. Where is the other 60 watts coming from?

Some chargers are more efficient than that, some are less. My Iota DLS-75A charger is very well regarded as a high current, low noise, stable power supply, but it draws 18.2A at full load. That's more than a Honda 2000 can handle, and a pretty good load on my Honda 3000.

[socaldmax]

Originally Posted by andyft

I have a 1000 watt generator connected to a 40 amp charger and 2 100ah batteries, works fine.

That must be an incredibly efficient model. Could you please share the brand? I think a lot of us could benefit from having that unit!

[btrayfors]

Originally Posted by socaldmax

Battery chargers don't put out 12v. They should be putting out at least 14.4v or they really aren't charging the battery. That's actually 14.4 x 40 = 576 watts, assuming 50% efficiency, that would be 1152 watts, continuous.

Even if it only put out 12v, 480w x 2(50% efficient) = 960 watts. The 1000 only puts out 900 watts continuous. Where is the other 60 watts coming from?

Some chargers are more efficient than that, some are less. My Iota DLS-75A charger is very well regarded as a high current, low noise, stable power supply, but it draws 18.2A at full load. That's more than a Honda 2000 can handle, and a pretty good load on my Honda 3000.

Yes, of course (re: the 14+ VDC). I was using the very common, "12V output" notation.

Now, to be precise:

The DLS-75/IQ4 draws a maximum of 18.2 A but that at 108VAC. That's 18.2X 108 = 1965.6 watts. However, at the nominal output of the Honda generator, 120VAC pure sine wave, 1965.6 watts equates to 16.38A. And, the DLS-75/IQ4 is certainly capable of that output.

More to the point....many persons have reported the successful use of an EU-2000i Honda generator with battery chargers in the 70-80A range in general, and the Iota DLS-75 in specific. Mine will do that, too, as I believe will yours.

Moreover, the maximum output is often only for a rather short time, depending on the SOC of the batteries, their condition, temperature, etc.

Bill

[socaldmax]

Originally Posted by btrayfors

Yeah, yeah, but that's all misleading for this OP.

He has a Honda EU2000i generator. This generator, at a maximum, will put out enough 120VAC current to power a 120VAC-to-12VDC external charger of about 80amps. It will not run a 100A charger or more, at least not flat out.

So, if he had a suitalbe charger for that Honda generator -- say an Iota DLS-75-IQ4, he'd be good to go in the mechanically run charging department. Anything less powerful would be wasting the generator's capability. Anything more than 75-80A output simply wouldn't run.

Of course, the 100A alternator on the main engine is the primary charging source, if properly regulated. One assumes he has an external, maybe programmable regulator, like the Balmar MC-612 or MC-614. If so, he's good to go if he sets that up properly.

I'd dump the batteries -- all of them -- and start anew, with all the same make and model flooded, gelled, or agm batteries. In that order of preference. A good even smallish solar panel & MPPT regulator would top off the electrical charging setup and keep the new batteries happy.

IMHO, it's not worth it fooling around with the existing batteries. Bite the bullet, get the right setup, and go sailing.

Bill

Bill, in essence you are correct, an 80A charger, if efficient enough, would be about the max. that the EU2000 can handle, since it only puts out 1600w (13.3A).

Unfortunately, the Iota DLS-75 is a very inefficient model, I have one in my RV, and based on Iota's published specs and my own experience, it draws every bit of the rated 18.2A, a full 5A above what even a well maintained EU2000 could produce.

First I had to install a 20A outlet and breaker for it, then if I was using my EU3000 (23.3A continuous) to power it, I had to shut off my 40A Xantrex inverter/charger because it simply could not power both, so I chose the 75A.

If I'm running my 60A Onan generator, then I can power both chargers, but that's never really necessary with solar panels. The 75A charger really isn't necessary any more either, but since I run the genny for 30 - 45 minutes for breakfast and dinner anyways (microwave, etc) might as well get a little boost off of it since it's running.

My solar panels are by far the biggest charging source on the RV.