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hammick's avatar
hammick
Explorer
Nov 30, 2016

Charger selection help please

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.

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  • hammick's avatar
    hammick
    Explorer
    Nov 30, 2016
    BFL13 wrote:
    26a is going to be slow charging on a 220AH bank, even at the right voltages. For generator charging you could use a 75 amp charger to advantage, where you would be doing "50-90" on generator. The 90-100 would be on solar or shore power.

    The PowerMax 75ADJ would be ideal, but will max a 2000w inverter-gen. I could just be able to run it. Some folks do with theirs. If you are at some altitude, where the 2000w runs lower, then the big gen would be needed.

    Here are some times it takes to recharge a 220ah bank 50-90 at various initial amp levels. You can see where 26a would fit in for time (go in below the 35a line) Times here are with Vector portables on two 27s--the 75ADJ time on 232AH would be similar to the 70 here on 220.


    Thanks for the great info. Does your opinion change if I am unlikely to be under 75-80 SOC each morning?
  • BFL13's avatar
    BFL13
    Explorer II
    Nov 30, 2016
    26a is going to be slow charging on a 220AH bank, even at the right voltages. For generator charging you could use a 75 amp charger to advantage, where you would be doing "50-90" on generator. The 90-100 would be on solar or shore power.

    The PowerMax 75ADJ would be ideal, but will max a 2000w inverter-gen. I could just be able to run it. Some folks do with theirs. If you are at some altitude, where the 2000w runs lower, then the big gen would be needed.

    Here are some times it takes to recharge a 220ah bank 50-90 at various initial amp levels. You can see where 26a would fit in for time (go in below the 35a line) Times here are with Vector portables on two 27s--the 75ADJ time on 232AH would be similar to the 70 here on 220.

  • hammick's avatar
    hammick
    Explorer
    Nov 30, 2016
    westend wrote:

    What do you think that NOCO charger is outputting for charge voltage?


    Noco spec sheet says:

    12v normal mode: 14.5v @ 26a
    12v cold/AGM mode: 14.8v @ 26a
    12v lithium mode: 14.2v @ 26a
    12v AGM plus mode: 15.5v @ 26a
    13.6v supply mode: 13.6v @ 5a
    12v repair mode: 16.5v @ 1.5a

    My guess is that after starting a second cycle that it won't stay in absorb for any amount of time. The repair mode takes four hours so that isn't generator friendly.

    It also has a couple 24v and 16v charge modes. I do have a military generator that has a 24v charging system so that would be another use.
  • westend's avatar
    westend
    Explorer
    Nov 30, 2016
    hammick wrote:
    Shadow Catcher wrote:
    Progressive Dynamics replacement
    If it were me I would use one of the Progressive Dynamics units.


    Thanks. I've seen those inexpensive PD replacement units. Easy to install but they don't have the voltages that I want and the absorb voltage is way low. Float is also low.

    What do you think that NOCO charger is outputting for charge voltage?

    If it was me and I didn't want a typical RV converter, I'd get a wheeled ferroresonant charger with a transformer, skip all that magic hoo-haw promoted by NOCO and others and get a decent charge into the batteries.

    Edit: I see you have posted that you'll be using the "Recovery" or Repair" setting of that NOCO. All I can say is good luck with it. I don't have much confidence in the settable/selectable switching power supply chargers.
  • hammick's avatar
    hammick
    Explorer
    Nov 30, 2016
    I do realize the Noco probably won't fully charge the interstates on the normal charge mode. What caught my attention was the AGM cold mode that charges at 14.8v or even the AGM plus mode that charges at 15.5 volts.

    My hope is that I could charge with the AGM cold mode and then immediately follow with the AGM plus mode and hopefully get 15.3 - 15.5 volts to the batteries for an hour. This is what the interstates need to get fully charged.
  • hammick's avatar
    hammick
    Explorer
    Nov 30, 2016
    Shadow Catcher wrote:
    Progressive Dynamics replacement
    If it were me I would use one of the Progressive Dynamics units.


    Thanks. I've seen those inexpensive PD replacement units. Easy to install but they don't have the voltages that I want and the absorb voltage is way low. Float is also low.

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