Battery chargers won't work on genset, work fine on SP

[Mischief Managed]

Hi Mischief, it's been 10 days since you posted the issue. What was the outcome/issue?

Sorry, was busy cruising on the boat...


I was able to get the Pronautic 12P50 working on the genset by bypassing the factory wiring to the three battery banks that made use of the diode-based battery isolator (which is probably failing). The charger was not turning on due to not detecting enough voltage on any of the 3 battery connections. When the inverter was charging properly, it must have been providing enough output voltage to make the Pronautic charger happy on the DC side. FWIW, the diode-based isolator will be going in the trash soon because I have a major re-wire project planned for my battery charging and distribution. For now, I am perfectly fine with 50 amps of charging when the genset is running.



The Pronautic charger has always had a ferrite on the 120V input and my guess is that it's filtering high frequency distortion off the genset output to make the charger happy. The Xantrex inverter did not come with a ferrite and I have ordered an assortment of them so I can add at least one to the AC input. Fingers are crossed that it will solve my issue.



My new oscilloscope delivery is delayed so I have not been able to see the genset output waveform to prove the need for the ferrrite, but they are super cheap, easy to install, and have no downside if you don't need them.



My genset output voltage is controlled by moving jumpers on a tapped transformer and can only be adjusted to one of 4 different settings (which are basically a "less", "normal", "more" and "even more"). I have it maxed out and am getting 118.3 volts RMS at 61.25 Hz to the inverter and the charger. The frequency and voltage are very stable.

 

[CMS]

I was able to get the Pronautic 12P50 working on the genset by bypassing the factory wiring to the three battery banks that made use of the diode-based battery isolator (which is probably failing). The charger was not turning on due to not detecting enough voltage on any of the 3 battery connections.

This is one of the major issues with diode or even FET isolators. They won't work with "smart" chargers or controllers etc. that need to see a battery voltage in order to turn on.

The Pronautic charger has always had a ferrite on the 120V input and my guess is that it's filtering high frequency distortion off the genset output to make the charger happy. The Xantrex inverter did not come with a ferrite and I have ordered an assortment of them so I can add at least one to the AC input. Fingers are crossed that it will solve my issue.

The Sterling ProCharge Ultra and the Pronautic P chargers are about as genset tolerant as we've ever installed. I actually have one at an off-grid hunting camp where the owners generator (no brand even on it, just a "Briggs & Stratton engine logo) and has to be at least 30+ years old. It is about as horrible as it gets at holding a steady RPM yet the ProCharge Ultra works beautifully and without issue.

 

[Swfla]

A situation where old technology and new make thing so complex. It took hours of hair pulling to find the problem. Glad it's sorted out. Hate to see you cruising with jumper cables and a timer as a temporary fix. Enjoy.

 

[Mischief Managed]

This is one of the major issues with diode or even FET isolators. They won't work with "smart" chargers or controllers etc. that need to see a battery voltage in order to turn on.

Interesting... I have always used this Pronautic charger as a backup and my inverter as the primary, mainly because the inverter puts out a ton more current and has a remote display in my salon that makes it easy to keep tabs on what's going on. I guess I never tried the Pronautic by itself.

The Sterling ProCharge Ultra and the Pronautic P chargers are about as genset tolerant as we've ever installed. I actually have one at an off-grid hunting camp where the owners generator (no brand even on it, just a "Briggs & Stratton engine logo) and has to be at least 30+ years old. It is about as horrible as it gets at holding a steady RPM yet the ProCharge Ultra works beautifully and without issue.

Good to know. Thanks for sharing your insight.

 

[Mischief Managed]

I fixed this issue and forgot to update the thread. It ended up being a problem with the way the previous owner had the old inverter wired. He was using the internal AC transfer switch in the old inverter and had the AC in hot lead wired directly to the main breaker. The inverter was not powered because I had the main AC in breaker OFF the last few times I was running the genset. I fixed the wiring and it's operating correctly now, regardless of the position of the main AC in breaker.


The waveform out of the genset looked great, BTW. Nice, clean, sine wave.

 

[tiltrider1]

So it looks like post #10 was on to something.

 

[PM]

This may be a no brainer, but have you checked your main switch? The big one which selects shore power or Onan power? Is it clicking solidly into position?

pete

 

[Mischief Managed]

So it looks like post #10 was on to something.

yup, thanks.

 

[Mischief Managed]

This may be a no brainer, but have you checked your main switch? The big one which selects shore power or Onan power? Is it clicking solidly into position?

pete

Yeah, if that was not set right, nothing else would work on genset power, and everything else worked fine.



The problem was due to funky wiring on the AC in that required the main shore power breaker to be on. It's fixed now.



The funky AC in hot lead was routed poorly and was pulled tightly against a neutral bus. Could have easily caused a fire. The factory wiring is much better executed.