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RDMueller's avatar
RDMueller
Explorer
Nov 07, 2015

Got a new Toy! PowerMax Boondocker adjustable 60A

Add me to the list of those who are putting aside the automatic "smart chargers" and going with something manual! I've messed with the on board Wiffco, a Battery Tender, various wall warts and the crazy Schumacher, learning as I go. Now I've finally found something that I think is going to work great (Thank you BFL)!

Fully adjustable up to 15.5V, but unloaded it gets pretty close to 16V. So it should be good for regular charging and equalizing. Maybe a little low for desulfating, but hopefully if I take good care of my batteries, I won't need to desulfate. Plus, for under $30 I can add the Drok boost voltage converter to the mix (Thank you Mex), and adjust the amperage as needed. At 60A, I can do a quick charge off the gen when dry camping, then when I get home, I can charge at C/20.

Now the only thing I haven't decided yet is whether or not to add an ammeter. It would definitely be useful, but I'm thinking I can get basically the same info by plugging the Boondocker into the Kill a watt.

  • BFL, I agree, I'm just wondering if the Kill a Watt will essentially give me the same info. Just take whatever wattage it's showing and divide by 10 to get a rough estimation of the amps going into the battery. Just how "rough" an estimate it would be, I'm not sure.

    This also kind of touches on something that was brought up a few months ago on one of my threads, whether or not a charger is PFC corrected. For instance, the Kill a Watt showed the following:

    PF .57
    Amps .73
    Watts 51

    Volts(122) X Amps(.73) = Watts (89)

    Then multiply the 89W by the PF(.57) and you get the 51W it was displaying. That all makes perfect sense to me. And I think it's safe to assume that in terms of watts, 51 is the number I care about. So, roughly 5.1A going to the batts...
  • May I beg you to twiddle the dials, press the pedal to the metal and find out precisely what the Boondocker can do for a living?

    With the booster: Find that magic point voltage wise between the Boondocker and DROK (The voltage Delta T) where the Drok no longer hates incoming voltage and refuses to boost. The DROK is fused for 20-amps (the 600 watt model) but in reality I would limit the DROK to say fifteen by means of an auto reset circuit breaker. At high loads the DROK demands a fan beneath the heatsink. Try and find a lot wattage 18 volt 60mm ball bearing fan and set the DROK atop it. Blowing upwards.

    I love that DROK with the adjustable current limit pot. BTW it's the outboard of the two pots. The closer you can set the incoming voltage to without violating the (It's too close!) rule, the less boost means less heat.

    If you feel like bothering, you can provide a wealth of details about the Boondocker. After reading what the Boondocker manufacturer had to say on this forum I am convinced they will never offer an adjustable timer for voltage absorbsion time limits, too bad. They almost got it right. The man needs to go camping somewhere where gasoline costs five dollars a gallon and a 50 mile round trip to go get it. Rude rude rude learning curve about generator run time and fuel and generator wearing-out. Maybe he delineates boondocking from off-grid. A month of boondocking changes things to off-grid status. I need to win a lottery that I never buy tickets for, so I can truthfully say "I have people that do that for me". Criminy I'd squander winnings on buying food for hungry people anyway. Sigh.
  • Looking good! :)

    I need an ammeter to tell me when to shut down the generator when I have done my 50-90 or 50-80 whatever. I find that at 90% SOC a 220AH bank at 14.5v will accept about 10 amps, so when my amps taper down to 5 amps per battery, I stop. (So at 20 amps for my four 6s)

    I don't know any other way to tell that. Of course you can use an AH counter, but that has an ammeter anyway. Smk says to just get the batts to 14.4 and let the gen run for another hour, which is a rule of thumb, but I like to know more exactly.

    I have learned with mine that if you leave it at 14.8 till amps get down to nothing much (so near 100%) before you drop to 13.x for your Float, that the SG will be up at baseline, and you will hardly ever have to do an "overcharge" (You can't do that with a 13.8v converter, the SG never gets that high, and a regular three stager will drop to 13.x too soon. The trick is to leave it up at 14.8 till it is done and then lower it.

    You can mark some handy voltages around the knob while the charger is disconnected from the battery, which makes life easier when connected and you want to change voltages.

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