Which chargers are most forgiving of dirty generator power?

[Saltyhog]

I'm installing a small diesel genset. It's a Maspower MPS-4000 (same as the old Entec West). It's rated for 3600 watts (30A, 120V) continuous. The main purpose of the genset is to bulk charge my 2x Lifeline AGM 8D's (510 AH @ 12V), or eventually a lithium bank as that technology matures. I'll also use it to make water with a 120V water maker. I want to run the genset as hard as possible for as short a time as possible. This is good for me and the genset. So my question revolves around the quality of the the power the genset makes, or rather the lack of quality. I know that these small 2 pole brushless gen-heads make "dirty" power, and that can cause problems with some chargers, lowering the available current output. I've narrowed my choices to either the Victron Multiplus 3000 (120 A charger) or a pair (or perhaps a trio) of Sterling 60 A chargers. I suppose the Magnum is also in the running. Based on rated output of the genset, I could run three Sterlings for 180A, but I don't know if they will actually yield full, or even close to full, output current when consuming the dirty power from the genset. I'm not even sure if the Victron or Magnum will work to full specs (120A). All units are "PFC" (power factor corrected) which would be a requirement at a minimum. Any experience out there as to which chargers are the most "forgiving" of dirty generator power?

[transmitterdan]

Salty, I don't know if anyone has done the experiments to answer your question. But I do know something about PFC. PFC only works correctly when the mains voltage is a pure sine wave. Some PFC implementations will operate with distorted voltage but may not give unity power factor. This is the primary reason many chargers don't work on "dirty" power.

[Saltyhog]

Originally Posted by transmitterdan

Salty, I don't know if anyone has done the experiments to answer your question. But I do know something about PFC. PFC only works correctly when the mains voltage is a pure sine wave. Some PFC implementations will operate with distorted voltage but may not give unity power factor. This is the primary reason many chargers don't work on "dirty" power.

Yeah, I figured that PFC is not the complete answer to the problem. I know that chargers with a poor power factor will draw more from a small genset than they are speced for. I'm guessing (just guessing) that a charger with a universal input voltage, like the Sterling, would be more forgiving. The inverter chargers, being limited to a much smaller voltage range, might be more picky. Inverter chargers which sync to the source (power assist) would have to be somewhat picky to permit that synchronization. But again, without knowing more, I'm just taking an educated guess here.

[a64pilot]

I can tell you that my Nexgen 3.5 has supposedly “dirty” power.
I have not put it on an O scope, but nothing I have seems to care, both my Sterling and my Magnum work perfectly, as does the TV and everything else.
I’d tell you to look real hard at a Magnum, and a Sterling.
That is what I have and gives me plenty of AC with inverter to run anything to include the Watermaker off of the battery bank and gives me 185 amps of charging, which pretty much maxes out my generator, and give me two chargers in case one fails.

If I’m running the Watermaker without running the generator, I’ll only do so when motoring, and using the 165 amp alternator to power it of course through the inverter

It’s nice to have an inverter to run a vacuum cleaner, blender, toaster etc without having to start the generator.
Lots of appliances can be bought in 12V, but I have found that they are usually poor quality, and very expensive.

Both my Magnum and my Sterling will output slightly more than rated power, continuously on the generator, the power output on generator and shore power is identical.

At least with the Nexgen, it’s just not an issue, not sure about others

[CharlieJ]

Saltyhog: Victron Energy tested 19 small gensets in 2007 to determine how well their MultiPlus paralleling inverter/chargers performed with these gensets. Here is the link to the final report: http://tinyurl.com/ya2px94p

[Williamp]

Hi,
I use a pair of 60 amp sterling pro charge ultras as you suggest. They run off a master volt whispergen 3500. They seem to work well producing their full output into a 580 a/h wet cell bank. Massively reduced generator time. Very pleased ( makes a change[emoji846])

[Saltyhog]

Originally Posted by a64pilot

I can tell you that my Nexgen 3.5 has supposedly “dirty” power.
I have not put it on an O scope, but nothing I have seems to care, both my Sterling and my Magnum work perfectly, as does the TV and everything else.
I’d tell you to look real hard at a Magnum, and a Sterling.
That is what I have and gives me plenty of AC with inverter to run anything to include the Watermaker off of the battery bank and gives me 185 amps of charging, which pretty much maxes out my generator, and give me two chargers in case one fails.

If I’m running the Watermaker without running the generator, I’ll only do so when motoring, and using the 165 amp alternator to power it of course through the inverter

It’s nice to have an inverter to run a vacuum cleaner, blender, toaster etc without having to start the generator.
Lots of appliances can be bought in 12V, but I have found that they are usually poor quality, and very expensive.

Both my Magnum and my Sterling will output slightly more than rated power, continuously on the generator, the power output on generator and shore power is identical.

At least with the Nexgen, it’s just not an issue, not sure about others

I was hoping you'd respond as I thought I remembered you had a Nextgen. Similar size and type of gen head so should be comparable. Your experience is really encouraging. The Magnum is bumped up to par with the Victron in my decision. I do really like how configurable the Victron is. I believe the Magnum is similar in this regard. We agree regarding use case of the genset and inverter. If I went with Sterling chargers, I'd also get an independent inverter for the reasons you mention. Good to know that a 165A alternator -> inverter can keep up with an AC powered watermaker, as that's my plan as well for when motoring. Thanks.

[Saltyhog]

Originally Posted by CharlieJ

Saltyhog: Victron Energy tested 19 small gensets in 2007 to determine how well their MultiPlus paralleling inverter/chargers performed with these gensets. Here is the link to the final report: http://tinyurl.com/ya2px94p

Thanks! That was very useful. It seems that generators similar to mine will work fine with the Victron Multiplus as long as I limit myself to only one Multiplus. No problem there. No mention of charger performance, but I assume it works fine based on the rest of the report. I like the Multiplus for charging if only because it uses remote voltage sensing for controlling the charge voltage. This is probably less important for lead acid batteries, but becomes important for lithium. As I mentioned, I'm trying to future proof the system for the possibility of lithium or another chemistry as that market matures.

[Saltyhog]

Originally Posted by Williamp

Hi,
I use a pair of 60 amp sterling pro charge ultras as you suggest. They run off a master volt whispergen 3500. They seem to work well producing their full output into a 580 a/h wet cell bank. Massively reduced generator time. Very pleased ( makes a change[emoji846])

Thanks! Your experience matches A64pilots WRT the Sterling. Good to know.