Problems charging batteries with a 300W inverter while travelling

Rene Thalmann · Mar 18, 2016

Hi everyone

I am having a 300W DC-AC Power Inverter - 12Vdc - 230Vac - 50Hz. It's not pure sine wave.
I remember we were having problems charging P3P batteries, and aborted that one. I now also have the P4's, preparing for a trip to NZ by the end of the month and need to be able to charge these batteries while travelling.
Does anyone have an idea why we are having problems charging P3P and potentially also P4 batteries with this inverter? Thank you

Cheers
Rene, Gold Coast Australia

John Locke · Mar 18, 2016

Rene Thalmann said:
Hi everyone

I am having a 300W DC-AC Power Inverter - 12Vdc - 230Vac - 50Hz. It's not Sinwave.
I remember we were having P3P batteries, and I also have the P4's.
Does anyone have an idea why? Thank you

Cheers
Rene, Gold Coast Australia

Have any idea of what?

Rene Thalmann · Mar 18, 2016

John
Sorry, original message slipped out prematurely. Has since been completed via editing. Idea of what = idea of why we are having problems loading P3P batteries with our 300W inverter. Here is the updated message:

"Hi everyone

I am having a 300W DC-AC Power Inverter - 12Vdc - 230Vac - 50Hz. It's not pure sine wave.
I remember we were having problems charging P3P batteries, and aborted that one. I now also have the P4's, preparing for a trip to NZ by the end of the month and need to be able to charge these batteries while travelling.
Does anyone have an idea why we are having problems charging P3P and potentially also P4 batteries with this inverter? Thank you

Cheers
Rene, Gold Coast Australia"

Szon3 · Mar 18, 2016

It has something to do with the sine wave, an depending on the inverter ,most put out a square or modified sine wave which a lot of battery chargers and some digital equip. don't like.

Sinisalo · Mar 19, 2016

Rene Thalmann said:
Hi everyone

I am having a 300W DC-AC Power Inverter - 12Vdc - 230Vac - 50Hz. It's not Sinwave.
I remember we were having problems charging P3P batteries, and aborted that one. I now also have the P4's, preparing for a trip to NZ by the end of the month and need to be able to charge these batteries while travelling.
Does anyone have an idea why we are having problems charging P3P and potentially also P4 batteries with this inverter? Thank you

Cheers
Rene, Gold Coast Australia

My guess is that since you are using 230v AC power you need an inverter with more watts, 500-1000 should be sufficient.

sar104 · Mar 19, 2016

It's not the available power - it's the waveform. Switched mode power supplies do not work well with non-sine-wave power, which is not surprising given how they operate. I would recommend investing in a better inverter.

Sinisalo · Mar 19, 2016

sar104 said:
It's not the available power - it's the waveform. Switched mode power supplies do not work well with non-sine-wave power, which is not surprising given how they operate. I would recommend investing in a better inverter.

people have charged P3 batteries with non sine wave inverters before, I agree that if it is needed to fly in a remote place a good inverter should be invested in.

sar104 · Mar 19, 2016

Sinisalo said:
people have charged P3 batteries with non sine wave inverters before, I agree that if it is needed to fly in a remote place a good inverter should be invested in.

Maybe so. Could be that some inverter waveforms are worse than others, and also that 230 V non-sine-wave inverters are worse than 120 V due to the shorter duty cycle.

Szon3 · Mar 19, 2016

You need to look for a PWM sine wave output in the specs. I had 2 1500w inverters in work trucks the one that had the pwm(pure sine wave) I was able to charge my dewalt were as the other one just kept blinking and never charged. The only thing I'm not sure of is the compatibility 50 hz seeing how any thing we buy in U.S. is 60hz

Dirty Bird · Mar 19, 2016

Try another brand inverter or purchase a true sine wave inverter. Most inverters approximate the true sine wave of AC power with a stepped or "square" wave. Many electrical items don't care...a light bulb for instance. But some electronic devices & motors are negatively affected by square wave power. Some will not work at all, & some particularly sensitive devices & motors can actually be damaged. I sometimes use a small 200 watt inverter to charge batteries in my car. My particular model works fine for P2/P3 chargers (haven't tested with the P4 charger but it looks almost identical to the P3 charger sans the color). A true sine wave inverter will be more expensive but will assure sensitive electronics & charging circuits work properly. Be sure to get one for your local AC frequency.

Rene Thalmann said:
Hi everyone

I am having a 300W DC-AC Power Inverter - 12Vdc - 230Vac - 50Hz. It's not pure sine wave.
I remember we were having problems charging P3P batteries, and aborted that one. I now also have the P4's, preparing for a trip to NZ by the end of the month and need to be able to charge these batteries while travelling.
Does anyone have an idea why we are having problems charging P3P and potentially also P4 batteries with this inverter? Thank you

Cheers
Rene, Gold Coast Australia

GreggC · Mar 19, 2016

Modified Sine Wave inverters WILL NOT WORK !!
Modified Sine Wave is considered "dirty power"
YOU MUST USE A PURE SINE WAVE INVERTER.

Dirty Bird · Mar 19, 2016

It isn't true that "all" square wave inverters don't work. Many do & have I have one that works fine. It isn't even an expensive model ($20). His is just outside the range of what the charger finds acceptable.

GreggC said:
Modified Sine Wave inverters WILL NOT WORK !!
Modified Sine Wave is considered "dirty power"
YOU MUST USE A PURE SINE WAVE INVERTER.

GreggC · Mar 19, 2016

Dirty Bird said:
It isn't true that "all" square wave inverters don't work. Many do & have I have one that works fine. It isn't even an expensive model ($20). His is just outside the range of what the charger finds acceptable.

I wouldn't risk it,
I wouldn't risk damage to the charger or battery,
The simple easy answer is to use a pure sine wave inverter.

Dirty Bird · Mar 19, 2016

I agree the preferable route is purchasing a true sine wave inverter.

GreggC said:
I wouldn't risk it,
I wouldn't risk damage to the charger or battery,
The simple easy answer is to use a pure sine wave inverter.

GreggC · Mar 19, 2016

Just a bit of trivia,
Once upon a time I purchased an electric blanket for my motor coach,
The first time I used it both remotes became so hot they actually melted !!
No kidding, no exaggeration...they melted !!
The issue was traced to a modified sine wave inverter I had installed
the previous year.
My coach is a 2003 so the TV's and other electronics are old and out dated,
They handled the modified sine wave.
New modern sensitive electronics must have a pure sine wave,
I learned my lesson, almost set my motor coach on fire !!

alokbhargava · Mar 19, 2016

I have designed power supplies and inverters and I understand the exact problem you are facing.

Your 12V DC to 230V AC inverter will not work for DJI charger cause it's a travel charger and it will have square wave output. If you continue to use it, transformer of DJI will heat up and burn. You could have serious consequences. Are you sure your battery electronics have not yet failed? Make sure it is ok. Take out the idea of using inverter with DJI charger. Full stop.

Charger with true sine wave output will be very heavy for traveling and will not thus be suitable and comfortable though it will work. PWM output wave will also be risky though better than square wave. If weight is not the consideration, you can buy a true sine wave inverter.

The best solution for you is to look for a 12V to 17.5 V DC to DC boost converter having minimum 5 Amp rating. Use it directly with the battery, no DJI charger in between. You may have to look for a matching connector to connect to the battery.

Best Wishes.