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.

[hammick]

BFL13 wrote:
So with the money you saved not buying all that other stuff, just get this and forget the over-priced puny 26amper. it will run on the 2000w gen.

http://www.boatandrvaccessories.com/powermax-pmbc-55adj-converter.html

Expect your JKill-A-Watt to show:
124.7v, 11.06a, 1383VA, 980w, PF 0.71 when unit is set to 14.8v output, with output 56.8a batteries to 13.7v and rising at the time.

Note the ad is wrong--it does not do three-stage, it runs at whatever voltage you set it to and stays there till you change it.

Forum member JiminDenver camps like you do at 10,000 feet without even an oxygen mask apparently. His set- up might interest you if he shows up here.

That looks like a nice charger but I'm now leaning towards a 36a Megawatt. It should do everything I need it to do and fits with my hands on and keep busy attitude while camping. If that changes with age I can always add a timer like Mex.

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

[BFL13]

So with the money you saved not buying all that other stuff, just get this and forget the over-priced puny 26amper. it will run on the 2000w gen.

http://www.boatandrvaccessories.com/powermax-pmbc-55adj-converter.html

Expect your JKill-A-Watt to show:
124.7v, 11.06a, 1383VA, 980w, PF 0.71 when unit is set to 14.8v output, with output 56.8a batteries to 13.7v and rising at the time.

Note the ad is wrong--it does not do three-stage, it runs at whatever voltage you set it to and stays there till you change it.

Forum member JiminDenver camps like you do at 10,000 feet without even an oxygen mask apparently. His set- up might interest you if he shows up here.

[hammick]

BFL13 wrote:

hammick wrote:

pianotuna wrote:
Hi,

My guess is that running in AGM mode will do exactly nothing to speed charging--and in fact it may be the exact opposite.

How much solar do you have?

hammick wrote:
But I have some hope that running the AGM plus mode after a normal mode might hold it at higher volts long enough.

My thought on AGM plus 15.5v mode wasn't to speed charging. It was to get them fully charged after running the regular charge cycle. It looks like getting them fully charged every day is not what most people do because of long generator run time to accomplish this.

Not sure what I'll try at this point. I do have the built in Onan 4000w genset but I hate running it just for charging. It's loud and thirsty. But if a 75a charger is what I get I'll use the Onan rather than buying another Yamaha. Right now the Onan is reserved for Microwave use and the rare occasion that we need the AC. If I had to do it over I would skip the built in genset. Just too loud to use on a regular basis.

Your Yamaha might well be able to run the 75 amper, since some people can run theirs with Honda 2000 at sea level. But----see below.

You don't need to run the generator to run a microwave. You can run one of those with a 2000w inverter. You would want four batteries instead of two in order to keep the input voltage to the inverter above the 11v inverter alarm.

If you are interested in that for off-grid (you can run the microwave, toaster, whatever during quiet hours too, when the generator is not allowed), then you could also check out inverter/chargers since you are looking for a charger too.

Some of those inverter /chargers have programmable chargers, which is what you want, and they can be a decent size in amps. 2000w inverter with 100 amp charger EG.

So spending your money here 🙂 you just bought an inverter/charger, a remote for it, and two more 6s. Plus some heavy wiring and a big fuse or two. Now you are all set to go off-grid sunshine or no sunshine.

If we camped more or spent more time in the trailer I would look into this. Quiet hours aren't really the issue as we mostly camp where nobody is around. Not disturbing the wildlife or us is the main priority. I have a small cheap inverter for the TV but it rarely gets used unless its raining hard.

We have pretty set routines and are away from the trailer a good part of the day hiking. Late afternoon or evening when the sun is still out is when I do my charging with the very quiet Yamaha. Beer or bourbon in hand and I like to keep busy so no need for a timer. When we camp in Colorado or Montana it's mostly in the summer and we are out in the open so the solar takes care of everything (single 160w GoPower panel that came with the trailer. I changed the CC to a Blue Sky 30a PWM so I could custom set the charging voltage).

If I decide to only charge to 90% I can do that pretty easily with several of the replacement converters available. However, I don't understand whey they all have absorb voltage at 13.6 volts. Hell my crappy Wyco will do that all day long and gets me no where. And equalization at 14.4 volts. That's not even close to what my batteries need for Absorb. Clearly these PD charges don't have GC2 batteries in mind. I would still need a separate charger to periodically get to full charge in the winter.

Also most of our camping is at elevation. Sometimes over 10,000 feet and rarely under 5,000 feet. Winter camping is the exception when we will camp at Missouri elevations. Too **** hot to camp in Missouri in the summer. So I would hate to get a 75a converter/charger and not be able to use my Yamaha at elevation.

[BFL13]

hammick wrote:

pianotuna wrote:
Hi,

My guess is that running in AGM mode will do exactly nothing to speed charging--and in fact it may be the exact opposite.

How much solar do you have?

hammick wrote:
But I have some hope that running the AGM plus mode after a normal mode might hold it at higher volts long enough.

My thought on AGM plus 15.5v mode wasn't to speed charging. It was to get them fully charged after running the regular charge cycle. It looks like getting them fully charged every day is not what most people do because of long generator run time to accomplish this.

Not sure what I'll try at this point. I do have the built in Onan 4000w genset but I hate running it just for charging. It's loud and thirsty. But if a 75a charger is what I get I'll use the Onan rather than buying another Yamaha. Right now the Onan is reserved for Microwave use and the rare occasion that we need the AC. If I had to do it over I would skip the built in genset. Just too loud to use on a regular basis.

Your Yamaha might well be able to run the 75 amper, since some people can run theirs with Honda 2000 at sea level. But----see below.

You don't need to run the generator to run a microwave. You can run one of those with a 2000w inverter. You would want four batteries instead of two in order to keep the input voltage to the inverter above the 11v inverter alarm.

If you are interested in that for off-grid (you can run the microwave, toaster, whatever during quiet hours too, when the generator is not allowed), then you could also check out inverter/chargers since you are looking for a charger too.

Some of those inverter /chargers have programmable chargers, which is what you want, and they can be a decent size in amps. 2000w inverter with 100 amp charger EG.

So spending your money here 🙂 you just bought an inverter/charger, a remote for it, and two more 6s. Plus some heavy wiring and a big fuse or two. Now you are all set to go off-grid sunshine or no sunshine.

[pianotuna]

Hi hammick,

15.5 may exceed the gassing voltage, depending on the ambient temperature. All that it is going to do is cause electrolysis of the electrolyte causing the liquid to bubble away like mad.

Rule of thumb is approximately one bubble per second--more than that is simply causing heating and excessive gassing.

hammick wrote:

pianotuna wrote:
Hi,

My guess is that running in AGM mode will do exactly nothing to speed charging--and in fact it may be the exact opposite.

How much solar do you have?

hammick wrote:
But I have some hope that running the AGM plus mode after a normal mode might hold it at higher volts long enough.

My thought on AGM plus 15.5v mode wasn't to speed charging. It was to get them fully charged after running the regular charge cycle. It looks like getting them fully charged every day is not what most people do because of long generator run time to accomplish this.

Not sure what I'll try at this point. I do have the built in Onan 4000w genset but I hate running it just for charging. It's loud and thirsty. But if a 75a charger is what I get I'll use the Onan rather than buying another Yamaha. Right now the Onan is reserved for Microwave use and the rare occasion that we need the AC. If I had to do it over I would skip the built in genset. Just too loud to use on a regular basis.

[BFL13]

PT are you saying that setting the Magnum to 15a input is the same thing as plugging a 125 amp charger into a 15a receptacle in a 15a circuit?

The 100 amper was pulling 122.7v, 15.57a , reading 1910VA and the watts with that was 1854. PF 0.97

Scaling up to 125 amps output, that 15.57 input would be 19.46a

I don't know why the Magnum quit when set at 23a running the 127a charger output. 19.46 is way under 23.

Were there other 120v loads on the Magnum besides the charger?

Did the Yamaha 3000 (23.3? ) pop or was it just the Magnum at 23 that popped?

My Honda 3000 (23.3) runs my 100 amper (15.57) and my 55 amper (11.06) total 26.63. I don't know how it can. I guess the combined load pulls down the input voltage more than it is when they run individually, so the combined VA is lower than the individual VAs added. Anyway it runs.

So really, the Yamaha at 23 should have run the Magnum's charger at 127 amps no sweat. Perhaps it is all about that Magnum (which was the duff one? )

[hammick]

pianotuna wrote:
Hi,

My guess is that running in AGM mode will do exactly nothing to speed charging--and in fact it may be the exact opposite.

How much solar do you have?

hammick wrote:
But I have some hope that running the AGM plus mode after a normal mode might hold it at higher volts long enough.

My thought on AGM plus 15.5v mode wasn't to speed charging. It was to get them fully charged after running the regular charge cycle. It looks like getting them fully charged every day is not what most people do because of long generator run time to accomplish this.

Not sure what I'll try at this point. I do have the built in Onan 4000w genset but I hate running it just for charging. It's loud and thirsty. But if a 75a charger is what I get I'll use the Onan rather than buying another Yamaha. Right now the Onan is reserved for Microwave use and the rare occasion that we need the AC. If I had to do it over I would skip the built in genset. Just too loud to use on a regular basis.

[pianotuna]

Hi,

My guess is that running in AGM mode will do exactly nothing to speed charging--and in fact it may be the exact opposite.

How much solar do you have?

hammick wrote:
But I have some hope that running the AGM plus mode after a normal mode might hold it at higher volts long enough.

[pianotuna]

Hi BFL13,

I don't pretend to understand it--but I can tell you it was an observed number in real life. I was in Estevan, SK in the Walmart parking lot. I deliberately ran the battery bank down by running a 446 watt oil filled heater, a 50 watt heating pad and my laptop for four hours.

As I knew I would be using the Yamaha 3000, I had set the limit on the Magnum remote to 23 amps. When I started the generator, the Magnum shot up to 127 amps and faulted. I immediately shut it down and got out the owners manual to learn how to limit the charge. I settled on 13 amps so that I'd not exceed the 27 amps per jar for my surplus acid AGM telecom jars. When I moved back to 15 amps, as an experiment, the charge rose again to 125 amps. I dialed it back down. I do not remember the charge voltage--but I do know I had previous set up a custom charge profile limiting the voltage.

The only explanation I can offer is that not all power factor corrected devices work as efficiently as each other.

13 x 108 = 1404 watts
15 x 125 = 1875 watts (which is pushing a 15 amp circuit too hard, but it won't cause an immediate trip of the circuit).

Since the Yamaha generator that the OP has can only do 1600 watts continuous--13 amps is probably the best setting.

Good luck to the OP getting to 100% state of charge on the generator. It is NOT a good idea from a cost per unit of power, even with AGM starved acid cells.

BFL13 wrote:
"To do this you will need a power factor corrected charging device. The Magnum 3012 inverter/charger can do up to 125 amps of charging on a 15 amp shore power supply. For a 2000 watt Yamaha that would have to be "dialed down" on the Magnum ARC remote from 15 to 13 amps and that would limit charging to about 109 amps"

I do not understand how all that can possibly work. My PF corrected 100 amper draws 1910VA by Kill-A-Watt when output is 100 amps at 14.x volts.

So howinheck can you run a PF corrected 125 amper from a "15a" circuit? The 100 amper was drawing 15.57 amps. (The VA was with 122.7v/15.57a) A PF corrected 125a is going to need a 20a circuit would think. ????

The 75 amper Kill-A-Watt figures are:
123.8v, 13.64a, 1693VA, 1241w, PF 0.73

So I can see there that if you dial down the Magnum which is still then PF corrected, you could do more amps output than 75 with a draw of 13a, but I don't know about 109a--seems like a lot.

[SoundGuy]

hammick wrote:
Soundguy I have a CTEK Multi 4.3a which is a great little charger. My only complaint is it doesn't have temp comp. I think you have to step up to the 25a get real temp comp. The small Noco chargers seem to be the same.

True, my CTEK 7002 does not have temp comp, the 25000 does. I recall someone here on the forums mentioning though that the 25000's temp comp is part of the + battery clamp which in turn doesn't make it too suitable for a permanent installation. To date I've only used my 7002 sitting on the trailer's A frame and wired directly to the battery with the supplied eyelet adapter. Next season I'll install the CTEK in my trailer's front pass through compartment where I mounted a PSW inverter and have 4 gauge cables running directly from the inverter input to the battery, my plan being to wire the CTEK output to the inverter input terminals rather than the battery itself as I'm confident any voltage drop over those 4 gauge cables will be minimal.

[BFL13]

It doesn't make sense to me.

The OP says he wants fast charging for when he doesn't have solar, so that means doing 50-90s. So that means a 75 amper.

Then he says he will only be dropping to 75% even with no solar, so a low amp charger will be good enough.

How does he plan to stay above 75% with no solar camping with just two 6s? For how long?

[MEXICOWANDERER]

The reason for unclarity is the OP has not looked at a 4-hour Intermatic Timer. They are spring wound tick-tick-tick timers and if by god I want one hour five minutes function it's resolution is +-2 minutes. Want 2 hours 25 minutes? 22 minutes? Twist that knob.

Two wires to connect. The knob's shaft and nut allows a hole to be drilled just like in my BORG.

I do not appreciate wasting my time outwitting a Singapore chip programmed in Calcutta. The object is to charge a battery. Flashing lights and Meaningless Menus are for mouth breathers.

Me, the one-and-a-half handed with a drill, crimpers, and 2 feet of 14 gauge wire could turn your wheeled charger into something that could knock that NoGo nightmare on it's sillyass rubber bumpers for $25.00

Is the concept beyond intellect? The instant you fire up a generator you FORFEIT brain-free RVing. People spend hours programming toy must-haves that require more expertise than an Apollo moon lander command module yet 5-year old's deduction how long to charge at a starting voltage of "x" makes them cranky?

Super Cyber Genius Psycopath Miracle One Touch...needs your money. So does your replacement battery store. Don't disappoint them...

[hammick]

Soundguy I have a CTEK Multi 4.3a which is a great little charger. My only complaint is it doesn't have temp comp. I think you have to step up to the 25a get real temp comp. The small Noco chargers seem to be the same.

[SoundGuy]

hammick wrote:
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.

When charging I use a 2000w Yamaha inverter.

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.

Now that the pundits have had their say I'll chime in and say I'm quite happy with my CTEK Multi US 7002 7 amp charger. Yes, I would have preferred the CTEK Multi US 25000 25 amp charger (competitor to the NOCO Genius G26000) but it was significantly more costly and I don't have a need to recharge often or to recharge using a genset so quick charging wasn't a concern for me. The upside to a stand alone charger like the CTEKs or NOCOs is just that - they're stand alone and don't require any modification to your trailer at all. Just turn off your existing WFCO and connect the portable directly to your battery (or batteries). Unlike my WFCO which I've never seen exceed 13.6 volts my CTEK does do an honest 14.4 volts (or 14.8 if selected) and on that basis alone has been a great investment. Considering the parameters you've discussed I'd say you have nothing to lose by buying that NOCO G26000 and trying it out ... my bet is it will serve your needs just fine. 🙂

[hammick]

pianotuna wrote:

... the battery bank, once it reaches 85% state of charge will only accept about 26 amps. That will be approximately 1/4 load on the generator.

Exactly why the 26a Noco could be the perfect charger for me. We rarely go below 75% SOC and if not running the heater would be about 90% SOC. This charger would only get used when the solar cant get it done.

Noco has very good chat technical support and their response to my absorption question is below. Basically there is a good chance that it won't hold absorption long enough during a second charge cycle to do me any good. But I have some hope that running the AGM plus mode after a normal mode might hold it at higher volts long enough. Batterymart has a 45 day return policy so I'm going to try one out and report back.

Thanks for all the good info and I'll give an update in a few weeks.


Noco response:

"The charge steps do not last a set amount of time. The chargers monitor how the battery is accepting the charge, and progress through the steps accordingly. So the it will remove the charge if the it senses the battery is fully charged"