Hello I have a Multiplus 2 charging a 1000Ah LiFePO4 battery bank. The Multiplus changes at 120A continuously no problems when on shore power. However if I try and do the same with my 4KW MDKBH Onan generator it struggles the charger runs, and then it trips and goes onto the inverter. After a sho…

Check the Onan voltage regulator (AVR) for “Droop” setting. This should be set to 0% (zero) You can have a look at the VRM - advanced - generator measurements graphs :chart_increasing: to see what is odd at the moment the problem arises. Post pics in this topic so we can have a view and maybe advi…

Please put the ONAN specifications in the topic! Is it in a Delta-Y connection (2 phase 110V coils) ? Is it rated 4 kiloWatt or 4 kiloVoltAmpere? Is it rated 100% service factor or 80% What temperature Class generator F or H ? Lots of numbers but very important It looks like a winding temperat…

tHd-A Harmonics current (3rd/9th/12th can f#ck up the generator coils and AVR sensing) can be measured with a DC clamp Ampmeter, but still says nothing about the voltage sinus disfom percentage. tHd-V sensed in the AVR will imbalance the AVR controller output, it should be visible in the VRM generat…

Thanks phaseshifter, for the information. The harmonics is what I am thinking the issue is, will an isolation transformer isolate the harmonics from the Multiplus affecting the generator??? If not what are my options???

An isolation transformer of that size is very expensive. An option is to fit an AVR with harmonics filter, you probably have the most inexpensive AVR original in your generator. Request your generator supplier for a quote to fit a new AVR capable of “tellecom” or tHd filtering.

kWe: 4 kVa:* 4 Speed (RPM): 50 Hz / 2400 RPM Phase: 1 Voltage: 110 | 220, 115 | 230, 120 | 240 Amps: 36.4 | 18.2, 34.8 | 17.4, 33.3 | 16.6 Fuel Consumption (L/hr | gal/hr): 1/4 Load: 0.8 (0.28) 1/2 Load: 1.0 (0.28) 3/4 Load: 1.3 (0.35) Full Load: 1.7 (0.44)

If this is 4 kVA generator, a 3,2 kW load is maximum applied at PF0.80i (inductive load) 16.6A x 240V x PF0.80i = 3187Watt The PF (power factor) load of an inverter is likely PF1.0 and therefor only to be loaded at 3200W / 240Vac = 13.33Amp

Thanks phaseshifter, and yes the generator details are totally correct, the Multiplus charger is 12OA at 14V, but with the losses say 2kw would be some where in the range of where we would be, well below the 3.6Kw you are saying. I am lucky to get 1/2 (60A) of this before it all becomes unstable. Y…

Hi Michael, It is important to review graphs from VRM monitoring when the generator is supplying power to the MultiPlus. can you post pic’s from the graphs for generator Vac/Aac and Hz and for the Batteries the Vdc/Adc and BMS cell Volt difference? Your generator is a 1 phase 2-coiled stator with…

[image] MP2 kills generator AVRs Q&A and troubleshooting I have a Multiplus-2 5000/48 here, V552, running with a Cerbo v3.52. I’ve been struggling with charging from the generator on this all winter, with the generator cutting out regularly and significant voltage drops (…

Multiplus 2 and Onan MDKBH 4KW generator

DIY

phaseshifter 13 July 2025 09:08 18

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Multiplus 2 and Onan MDKBH 4KW generator

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