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BFL13's avatar
BFL13
Explorer II
Sep 28, 2017

Max Charging Amps with Honda 3000i Gen

I have reported in the past that I can get about 156 amps to the battery bank using the Honda 3000 where one 100a PF-corrected PowerMax is in parallel with a non-PF corrected 55a PowerMax (both adjustable voltage set to 14.8v)

Lately, I improved my set-up with a fatter wire in one place and found a loose connection that I fixed. This had the effect of reducing the voltage sag when on inverter drawing 124 amps (MW) from 1.0 volts to only 0.6 volts.

The surprise was also it improved what amps I get to the battery according to the Trimetric. Now I have really maxed out the Honda, where with the battery bank down 226AH and at 12.1v (half way down approx.--suggesting bank is 452AH) I ran up the chargers and got--ta da! 159 amps.

BUT after five minutes the Honda popped its breaker. Restart, ran a little and popped again. This was in Eco so I put it on full. Popped again. Drat. OK so I dialled the 55 amper down to 14.4 since it didn't matter about the 14.8 this early in the recharge. Now the Honda held and the amps stayed at 159

Reason, I think, is it is all about VA and the 55 amper doing 55 plus amps wants more VA when set to 14.8 than when set to 14.4. Anyway now the Honda kept going no sweat. Later when amps tapered a bit I cranked the 55 back to 14.8. I did not try to confirm this with a Kill-A-Watt at the time. Maybe next time.

So I am definitely at the limit of what the Honda 3000 can do. BUT I am not at the limit of what the batteries can take in. Once I got the chargers sorted out, so I could tell what they were doing themselves, I added in my solar. At the time, the solar (also set to 14.8) was pulling in 13 amps.

The Trimetric showed charging at 172 amps. I think the battery bank is good to about 450AH from what I can tell, so 172/450 = 38% charging rate. I believe they could take more in at 50% SOC than that, but I can't do more. I am "generator limited."

IMO this shows that anyone who has say, a PF-corrected inverter/charger that charges at 150 amps can run it with a 3000w Honda. Note, I cannot run a non-PF corrected PowerMax 75 amper and the 55 amper -total 130 with the Honda 3000. You need some PF correction to get the VA down. I was able to run 130 amps worth of Vector chargers with the Honda though. They are not PF-corrected but they are not as VA hungry it seems.

I suppose the real lesson here is that if you are pushing your luck, you can't go with just theoretical numbers, you have to do some trial and error. Let some other sucker find the limits on his money! :)

This was a classic gen in the morning then solar for the rest of the day after a few days in row with little solar input. Had to do a big catch- up and then was back to solar only with better weather.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Ah you still had a few watts left on that Honda.. Not many but a few.
  • j-d's avatar
    j-d
    Explorer II
    MEXICOWANDERER wrote:



    I really like these things. Good for all manner of testing. Tire temperature leads the list for me.

    Remember, though, the Laser Dot "might" be helpful for targeting the surface to measure, BUT...

    Instructions point out what's obvious once we think about it: The Laser Dot isn't doing the measuring, only helping your aim. The farther the tool is away from the surface being measured, the more "averaged" the reading is going to be. Large object like a Battery, at less than a foot distance, no problem. Tiny component you want to check, big problem. Tool needs to be so close that we need to to be sure the sensor is actually "looking" at the component and not the board next to it.
  • WHy do you need to cook the batteries so much? They must be boiling away? I use solar when dry camping with two Trojans t-125's and have yet to have a need to pump so much into the batteries. I also use a 3000i but charge regularly through the house charger
  • BFL,
    Keep on experimenting. Interesting that you are able to squeeze out the big amperage with all three charging sources in motion.
  • Hi MEX,

    I do "shoot" my batteries, but in fact the testing done was at about -10 C, so I doubt over heating would be an issue. The banks in question are "surplus acid" AGM telecom jars. Maximum charging rate is 27 amps each x 4 = 108 amps.

    Maximum safe temperature is?

    I had deliberately put them under a 442 watt heater load for three hours. I can't remember if I was running the fridge on 120 volt power.

    It is where I learned to limit the input amperage to the Magnum so as to not charge faster than is recommended. I wish the Magnum had two settings--one for input amps and another for limiting output amps on the charger, but that does not seem to exist.

    Before I learned to do the setting--I placed an extra load on the generator so as to limit the charging amps.
  • Don, I sure recommend you get your mitts on a ...



    Which will insure you are not over amping the battery. I shoot sides of cells then both pos and neg posts.

    Play around with normal charging temps. Use Delta T calculation for absolutes.

    Immersed in a liquid the only way to do a plate burn through would be an absurdly high shock of excess wattage.

    With the BORG charger I worry not. Close to 100 amps because the entire country is fixated with 30 amp breakers or fuses. Too much voltage drop at the receptacle? A twist of the wrist dials the Borg back, enough that an ancient Honda 600 or Harbor Fright 800 loads right to the last noodge of wattage. But the BORG is not PFC. I am getting ready to design a twin Meanwell RSP 1500-15 charger. This will be a 140 amp monster and it will have PFC and remote thermistor sensing for the float unit.

    If ANYONE out there has broken, old, ugly unused 15 amp chargers out there I will buy them. For the Hyperwatt and 3KW Borg projects. PM me. Old fashioned 15 amp chargers were about the size of a 12-inch cube
  • I should have said the battery bank in the OP is two 6v Exide 135s rated at 226AH new (now 6 years old) and two Trojan 1275s rated at 150 each when new but also six years old -first two in a golf car getting beat up) I have them in a sort of series parallel mash-up that works great.

    New that would be total 526 but now est at 450 so 450/526 = 85.6% which is about what I got on my last capacity tests on these. They should be good for another year or two the way things are going so far.

    I am impressed with these Exide 135s that have outlasted my Interstate GC2 XHDs (232AH) I had to toss at the six year point. Of course now Interstate has gone over to using Trojan T-105s as their new 6v at 225AH, so whole new ball game there. I just love my T-1275s, which seem to be impervious to all abuse. They are not much below what they were four years ago when I got them from the golf car place.
  • Hi BFL13,

    My limit is 125 amps on the Magnum 3012. It poops out at 127 amps.

    However, my batteries can't do more than 108 amps safely, so for me it is a non issue.

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