May 9, 20251 yr Morning GuysI have a bit of a challenge. I have my whole house running on a 10Kw Microcare low frequency inverter and 9.5Kwp of solar. I have been off grid for a number of years now. I recently got a caravan with a Felicity 5Kw inverter and Dyness lithium battery. I want to use excess solar from my home Microcare system to charge the battery in my caravan. I connected the Felicity mains input to the Microcare output. The charging works, however the Microcare inverter is making a disturbing “buzzing” sound very similar to when using a hairdryer on a low setting. I tried lowering the charge rate from 40A to 10A and there is no difference in the buzzing.I have read many articles about inverter noises and seem to think (in my ignorance) there may be some form of power factor that needs correcting, or something is out of phase. Does anyone think that adding a big lawnmower type capacitor in parallel with the Felicity inverter input might help eliminate this buzzing? Or is there something else at play here? Any advice would be appreciated.
May 9, 20251 yr Purely hypothetical. If you're charging a battery, you probably connecting to a step-down transformer to get the Voltage from 230V to 53V. Issue could be harmonic distortion of transformers in series. Earthing? Filters?What happens if the battery is full and you're not charging it, and just running a steady resistive load like a kettle from the Felicty inverter?
May 9, 20251 yr Author 29 minutes ago, GreenFields said:Purely hypothetical. If you're charging a battery, you probably connecting to a step-down transformer to get the Voltage from 230V to 53V. Issue could be harmonic distortion of transformers in series. Earthing? Filters?What happens if the battery is full and you're not charging it, and just running a steady resistive load like a kettle from the Felicty inverter?I was also thinking of a filter on the output just before the Felicity, but not sure if it would do any good. I will do some research on harmonic distortion. I will try boiling a kettle in the caravan when the battery is full to see if there is a difference.
May 10, 20251 yr Author On 2025/05/09 at 12:17 PM, GreenFields said:What happens if the battery is full and you're not charging it, and just running a steady resistive load like a kettle from the Felicty inverter?When the battery is full and the Felicity Inverter is sitting “idle” the harmonics from the Microcare inverter get very loud. It sounds like a loud metallic vibration. In that state I turned the kettle on and everything went quiet. Here is a reading of the noise.
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.