Charger selection help please

[hammick]

I'm thinking about buying a Noco Genius G26000 26a smart charger for when the sun isn't getting my batteries charged.

I have a FR Stealth Toyhauler with two Interstate GC2 208ah batteries. They do everything I want and more when I am able to get them fully charged. 99% of our camping is boondocking and our solar system will get the batteries fully charged during the summer assuming it is sunny and we aren't in the woods. I have a crappy 55a Wyco converter that never gives more than 13.7a to the batteries.

We boondocked for four days over Thanksgiving and it got quite old hauling out my Schumacher 25a cart charger to get the batteries fully charged. Plus the Schumacher gets the batteries over 16v when in absorb.

When charging I use a 2000w Yamaha inverter. I do have a built in 4000w Onan if needed.

I've read about all the threads on replacement converters, the Meanwell power supplies and other options. But I keep coming back to the Noco for it's many charging options and convenience.

Can I get these batteries fully charged using the Noco in a reasonable amount of time or should I go with something like the Powermax Boondocker with adjustable voltage or a Megawatt. I'm willing to pay the premium for the Noco but not at the expense of hours of extra generator time.

[theoldwizard1]

hammick wrote:

Priorities are:

Getting 208ah batteries fully charged from 75% SOC to full quickly

Doing this means NOT using a 3 stage smart charger and likely shortening your battery life.

Its your money ! Do what Mexicowander says. Get the biggest charger that you can reasonable carry and hook it to a mechanical 15A lamp timer.

Don't expect your batteries to last more than a couple of years with that kind of abuse.

[jharrell]

pianotuna wrote:
6. ARC remote set to 13 amps to limit charging rate to 108 amps

I can only figure 12.88v at 123 input volts at 87% efficiency unless I am missing something.

Your Magnum had in issue though right? Maybe it wasn't limiting correctly or had higher than 87% efficiency somehow.

[jharrell]

MEXICOWANDERER wrote:
The 27 year-old Trace 2500SB had a manual setting right on the control panel to limit charger amperage. In this day and age of "Look Ma No Brains!" a chip has to decide the obvious...

Magnum Energy was started by Ex-Trace guys...

The Magnum has a separate setting for just limiting charge amps in percentage of max, this is how you limit it if you don't want it feeding 125 amps into your wet cells.

[pianotuna]

jharell,

The equipment:

Yamaha 3000 sIEB inverter generator
Magnum 3000 hybrid inverter/charger
556 amp-hours of surplus acid AGM telecom batteries
ambient temperature about 4 c (39 f)


The sequence of events:

1. deliberate discharge for testing purposes, between four and five hours @ 600 watts.
2. Yamaha 3000 sIEB as a power source
3. ARC remote set to 23 amps to NOT overload the Yamaha
4. Magnum starts to charge and amps rise extremely quickly to 127
5. Magnum shuts down charging to protect itself
6. ARC remote set to 13 amps to limit charging rate to 108 amps

2 hours later charging rate under 10 amps

[MEXICOWANDERER]

Load support...

When I hear the turbo on the Kubota start to whistle...

The 27 year-old Trace 2500SB had a manual setting right on the control panel to limit charger amperage. In this day and age of "Look Ma No Brains!" a chip has to decide the obvious...

[BFL13]

It sounds like the Magnum would go into load support to run its own charger 🙂 Like when you forget to turn off the converter when on inverter. Anyway you Magnum guys can figure it all out. 😞

[jharrell]

BFL13 wrote:
On the Magnum, is it possible the input setting only "passes through" that amount, but the power that gets to the internal charger is not restricted by that setting to the same degree?

Its not a restriction in front of the charger, the charger itself backs off.

From the inverter manual:

" 03A AC Input Amps – This setting ensures that the combined current draw from the battery
charger and the AC loads does not exceed the maximum input current that is available from
the incoming AC power. This setting is used to set that maximum input current level.
Whenever the incoming AC is connected and passing through the inverter, the current used to
power the AC loads and charge the batteries is monitored. If this current begins to approach
the AC Input Amps setting, the charger current is automatically reduced. This ensures the AC
loads have all the available current from the incoming AC power when needed.
If using a MSH-M or MSH-RE (Hybrid) inverter, the AC input settings also determine when
the battery current begins to operate in parallel with the incoming AC power to support the
inverter loads (i.e., Load Support). The Load Support feature uses additional power from the
inverter’s battery to run loads greater than what the incoming AC power can run alone, and
prioritizes the power of any external DC source (i.e., solar, wind, etc.,) over the incoming AC
power to run inverter loads."

[BFL13]

On the Magnum, is it possible the input setting only "passes through" that amount, but the power that gets to the internal charger is not restricted by that setting to the same degree?

[jharrell]

BFL13 wrote:
IMO the 13 amps "in" was a 13 amps setting (not a measurement?) Just what the charger "saw" at its own input and where that came from is the mystery.

The Magnum has the setting and meters for AC amp in/out and DC amps. The Magnum charger will not exceed the setting for any length of time in my observations of both the Magnum AC input amp meter and my Surge-Guard amp meter that supplies the inverter.

Perhaps piano's absorb setting is 14.6 but at the time of measurement it was in bulk and closer to 13v? The other possibility is max input amps was actually set to 15 not 13?

Maybe I will try and run some tests to verify.

[MEXICOWANDERER]

On topic exercise...

Power supply ouput cables tip. This will appear in Megawatt mods upcoming article.

Buy two lengths of Ten gauge cable. I like the silicone wire offered on eBay. Usually red/black 5 ft pairs descibed a 10' heads-up. Longer pairs are available.

This is ultra flexible ultra fine-strand tinned copper wire.

I recomnended tapping all three pos and all three neg terminals then manifolding three into one larger cable your choice.

With ANY wire to terminal board connection strip the wire. Then DIVIDE EVENLY the strands sticking out. A "Y" shaped stripped end.

This allows heavy gauge capacity and divides the load on the circuit board terminal screw. On the BORG I used SOLID 12 gauge bare conductor then manifolded the three to a 10 gauge to shunt.

SPLIT ENDS suck when talking about hair but they are the Hot-Setup for power supply terminals.

[BFL13]

pianotuna wrote:
Hi BFL13,

It is odd that's for sure. But the 13 amps in with 108 amps out was a real life measurement. I'm guessing at the voltage, because I don't remember it.

IMO the 13 amps "in" was a 13 amps setting (not a measurement?) Just what the charger "saw" at its own input and where that came from is the mystery.

[pianotuna]

Hi BFL13,

It is odd that's for sure. But the 13 amps in with 108 amps out was a real life measurement. I'm guessing at the voltage, because I don't remember it.

[BFL13]

Sideshow to main topic.

PT, I am still not getting this Magnum business. You said:

"Limiting input to 13 amps @ 122 volts (1586 watts) limited output to 108 amps @ 14.6 volts DC"

But Output 108 x 14.6 is 1577 watts. Magnum claims efficiency is 87%, so input watts would be 1813 watts, not 1586w.

Then you apply the PF (0.97 say) to the input watts to get VA required from the power source so 1813/97 = 1869VA (remember my 100 amper needs 1910VA)

So setting the input limit to 13a cannot be actually limiting the input the way you think or the output could not be that 108 x 14.6.

Something is funny about that Magnum input limit setting as to what it actually does inside the Magnum.

[hammick]

landyacht318 wrote:

hammick wrote:

Anybody have a link to the nifty shunt/voltmeter mod for the Megawatt? I can't find it on Ebay.

Not sure what you want, An Ammeter?

No shunt required with this ammeter:

https://www.amazon.com/gp/product/B01DDQM6Z4/ref=s9_dcacsd_bhz_bw_c_x_3_w

Thanks Landy. I like the over the wire one. Nice and simple for me. Can you recommend some good eyelet crimps to make the DC cables. I think I will start my Megawatt or Meanwell project as a portable unit so cables will be three feet or less. Better yet pre-made battery clamps would be nice. Thanks.