new power max converter, problems

Voltage drop is proportionate to the amps flowing. Your batts are full so there are no amps flowing and so no voltage drop.

The converter appears to be working properly. It is the path from converter to battery that has such high resistance right now that is screwing things up for being off-grid. The high R could be too long, too thin wire, loose connections, or some of each.

Ok, I am not getting voltage drop anymore and the converter is not humming anymore. I have to get on my knees and put ear next to converter to hear it.

So, I unplugged shore power let it sit for couple hrs. Plugged back to shore power and now the converter is very quiet and at converter the volts read 14.7 and at batteries read 14.6. And now every time I check voltage there is only .1 difference between bats and converter (currently, con is 13.6 and bats 13.5

Did the converter "burn" itself in as Randy said it would and now it is performing correctly. Waiting for him to call back.

Be careful about using jumper cables as BFL13 suggests. Some use very thick insulation with #6 or smaller wire. The thickness of the insulation gives you the impression that you have thick wire. (Plastic is cheaper than copper) Better jumper cables have at least #4 wire.

1600 generator: It is a coleman powermate 1600 sport and it is rated at 1300 and surge at 1600. I have 2 RV deep cycle les schwab batteries and they are brand new.

I left trailer on shore power all last night and today with no load. volts at batteries and converter are 13.17.

shane102 wrote:
I will be using generator for charging most of the time. Small gen is a 1600 watt and big gen is a 3500 watt. I will be using 1600 mostly and using 3500 when I need air conditioner.

What changes do I need to do for charging with generator.

Is the 1600 rated or surge? Honda 2000? 1600 rated Honda will drive the 55 amps but 1600 surge might be 1200 rated and possibly overload.

How many batteries again?

I honestly think you would be better with a PD or IOTA close to the battery. PowerMax is better IMO for mostly pedestal hopping.

with the batteries at 12.1 at start, the converter should have gone back to 14.6 after the 15 minute thing, and stayed at 14.6 for some time before dropping to 13.6. As it is, you might as well have kept the WFCO! :(

To prove the PowerMax is working right, if it were me, I would haul it out, use shorter cables close to the batteries (probably with a set of ordinary jumper cables, and on low batteries, make sure it does some time at 14.6 past the 15 minute point. Right now the numbers are confusing, but could be due to voltage drop, don't know.

For generator charging, you need to stay at 14.x once the batts get that high. I like the adjustable voltage PowerMax for that to the highest amps you can run with the generator. Note that the 75 is PF corrected so it draws the same as the non-PF 60. Might be ok with the 1600 if that is VA not watts (A Honda 2000 is 1600 VA).

For generator charging on the 1600, you should set the converter up near the batts same as above, and get some time at the 14.6 volts till it drops to 13.6. If that is close to 80% SOC (hard to tell without a Trimetric)then IMO adopt 50-80s as your off-grid procedure till you can get shore power and "recover" the batteries.

If you don't mind using the 3500, then you could get a 100 amper and use both for a 155 amp fast recharge in Bulk

i did not read your posts before leaving and pulling the batteries down. Batteries are brand new and fully charged

So, here is another voltage test (probably getting boring).

The batteries are now at 12.14 volts. Turned on shore power and volts at output are 14.48 and at batteries 13.38. fan kicked on at about 4 mins and ran for about 1 min then shut off and volts at output read 13.6 and read 13.3 at battery.

Things seem to be working fine, I think. Other than the voltage drop.

I will be using generator for charging most of the time. Small gen is a 1600 watt and big gen is a 3500 watt. I will be using 1600 mostly and using 3500 when I need air conditioner.

What changes do I need to do for charging with generator.

No further testing is needed. No need to cycle the batteries.
Just leave it plugged in. You are ready to camp.

If you plan to charge on generator would be the reason to make changes.

Can somone send down an exocist to pull the evil out of my Whiffco after running at 13.6 for nearly a year?

Not clear what state the batteries are in. Need SGs or a resting voltage before you drain them down again. If the batts are indeed full, the converter must be running the loads at 13.2 Float without being kicked back to 13.6.

I don't know what it takes to get them back to 13.6 with that converter. (or why it would be necessary if it is running the loads ok) ISTR WFCO or PD blurbs do say that running loads will bring their converter back to 13.6 from 13.2 Float.