Parallel powermaxes outputs

time2roll wrote:
I would be tempted to put a switch on that resistor to switch from automatic to manual.
Or did I interpret that wrong?

That is not how it would work. The ordinary PM has a 15 minute timer same as the Iota's, so it always goes to boost at first regardless of the battery SOC. Then if the batt v is near 14.4 , it drops to 13.6 but if the SOC is still below 14.3ish, it will remain in boost and take the batts to Vabs and then drop to 13.6---ok with that as background:

The adjustable model has a pot that has a voltage range after the first 15 min from 12-15.5v But at first it has a range of 13-16.5v. After the 15 minutes are up whatever voltage you have set drops 1 volt. This can be confusing! :)

Ok, so if you just want to set a voltage at the start and then it stays there, you can snip the wire to R1 which now kills that initial 15 minute thing and the higher voltage range to 16.5. Now it will only go to 15.5 right from the start. So now you can set 14.8 at first and that is what you get the whole time. You don't have to reset the voltage after the first 15 minutes.

Errin said the reason the unit does that is because the adjustable voltage model was designed for car showroom customers who want that one volt drop 15 minutes after it starts from whatever voltage they set it to initially. ( I wonder if that sort of replicates what an alternator normally does after starting a car? No idea)

Waiting 15 min to reset the voltage is certainly not very handy for RV use, but they sell many to car people. RVers are just extra. And you can snip R1 if you know how (or else leave it alone!!!! :( )

BTW, I left my 75ADJ with R1 intact so I can have a charger that will do 16.5 which I never had before. It works on the T-1275s to get them really bubbling. Their spec for Equalizing is 16.3ish. I just unplug after 15 min and plug back in. Three of those is an hour.

time2roll wrote:
I would be tempted to put a switch on that resistor to switch from automatic to manual.
Or did I interpret that wrong?

You read it right , when I got my PowerMax it didn't perform like a manual charger even though it had the potentiometer.
After removing resister 1 it now stays at any voltage I set it too like its supposed to.
Really no need for a switch because if you want it at 13.6 volts just dial it to 13.6 volts with the pot.

I would be tempted to put a switch on that resistor to switch from automatic to manual.
Or did I interpret that wrong?

time2roll wrote:
PowerMax does tend to drop to float 20 minutes after reaching 14.6 volts (at converter) and battery about 75% charged. The more amps the lower the state of charge when PM drops to 13.6 volts. Makes for a very long absorption time to 90+%. A second PowerMax may even slow you down.

If you are spending money on a converter to get a quick charge I only recommend IOTA or Progressive Dynamics.

Mine used to drop down to 13.6 volts after 14 minutes , I was told by PowerMax to remove resister 1 and it would then hold the voltage at 14.8 volts if I set it there , it worked!!!

Missed that. I would still stick with the single 75A with a single Honda.

time2roll wrote:
PowerMax does tend to drop to float 20 minutes after reaching 14.6 volts (at converter) and battery about 75% charged. The more amps the lower the state of charge when PM drops to 13.6 volts. Makes for a very long absorption time to 90+%. A second PowerMax may even slow you down.

If you are spending money on a converter to get a quick charge I only recommend IOTA or Progressive Dynamics.

He has the adjustable voltage 75 amper, so that is not an issue.

IMO keep running that 75 with the Honda 2000 you have, and buy a PM 100 amper (ADJ) ( pulls 1910VA) and a Yamaha 2400 to run that along with your additional batteries.

You don't have to parallel the generators, just put both chargers (dialed to the same voltage) on the four batteries and now you can get 175 amps.

PowerMax does tend to drop to float 20 minutes after reaching 14.6 volts (at converter) and battery about 75% charged. The more amps the lower the state of charge when PM drops to 13.6 volts. Makes for a very long absorption time to 90+%. A second PowerMax may even slow you down.

If you are spending money on a converter to get a quick charge I only recommend IOTA or Progressive Dynamics.

The PM 75 ADJ is not PF corrected despite what the ad says. PM is going to correct that ad.

Measuring the 75 with the Kill-A-Watt you get 13.64 amps and 1693VA and PF is 0.73 while the output is 75 amps

You are fortunate that your Honda 2000 will do better than its rated 1600VA (at sea level)/ 13.3 amps, and produce the 1693VA at whatever height you are. You are right at its limits.

My 100 and 55 also go above the 3000 limit and it runs them, but it will not run the100 and 75. It can't run the 75 and 55 either, which are both non-PF corrected. So there is no way you can run two 75s with the 3000 either.

ISTR Yamaha has a 2400 that would suit a 75 amper much better, but I don't have one of those

valhalla360 wrote:
The Honda 2000 is rated for 1600 continuous watts. 150amps at 12v is 1800watts before considering losses.

At best the little Honda will be running flat out and won't be quiet. Assuming it doesn't cut out from overload, it will put a lot of wear and tear on the generator.

Also, what size is your battery bank? Unless it's pretty big, it won't be able to absorb 150amps.

I have a PowerMax BPCM-75 PF corrected Adjustable model ,,,My Honda 2000i runs the PowerMax pumping 75 amps into two gc2 6 volters (12 volt bank) and the Honda barely comes out of Eco mode and runs pretty quiet and then when the amps start to drop gets really quiet .

I was thinking of adding two more gc2 batteries for a total of four and then run dual Powermaxes

A single Honda 2000 will not put 150 amps into a 12v battery.
Well into overload territory.