Charging in car with inverter

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First post. I figured I'd post this here, as the standard is what I have.

Enjoying the drone. Have about 15 flights so far. I suppose I'm fortunate with range, I've been out 5k feet from my house with no warnings. Rural setting. I think any more range would be a novelty for my purposes. I have a drone to be a flying camera to document family travels. I suppose the vast majority of my flights will be close by, as having the family in the shot is the whole purpose.

There, that's a brief intro.

I purchased a Foval 150w car inverter. It works well for everything I've tried (laptop and camera batteries). My main purpose was to charge the drone while driving from location to location. When my truck is running, the drone will not charge. When I shut the truck off, it charges. Any ideas what's going on?

Looking forward to being a part of the community. This thing is FUN! Hoping someone gets an extra battery for Christmas!
 
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Where did you take the power connection for the inverter from?

Are you saying the laptop and camera batteries do charge while the truck is running?
 
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Yes, everything else charges while running. The inverter also has a power light on it. That light is on in all conditions. I've tried it on all 3 outlets in the truck.
 
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Tragusa3- do you have a Nother cigarette charger in your truck that you can try? I only ask because my truck does the same thing. One cigarette lighter always stays hot (truck on or off), and the other cigarette lighter only works when the truck is running. I believe it's the way the vehicle manufacture intended it to work.


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I've tried all outlets. The inverter has power when the truck is running, and will charge other devices.
 
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Mm mm interesting.

There are two factors that change between having engine running and not.

A) voltage when engine running is up higher to anything from 14v to 15.5v depending on car battery state and what you have also switched on.
B) output watts of the ciggy socket can fluctuate during engine running ...

The DJI unit may be extremely sensitive to fluctuations and its regulator shutting of with them. When engine is not running - the power is smoother and inverter will have better output especially if its a cheap unit. Cheap units are extremely 'dirty' in their output and many items will refuse to work with them.

What happens if you have engine running at steady idle and with headlights on ? This helps some units in smoothing the load .... but not when driving particularly if the alternator regulator is not the smoothest.

Easiest option is to buy a direct car charger for the battery's ... eBay has loads for just a few dollars. Enter DJI battery car charger in the search bar.

Nigel
 
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Thanks for all of the quick replies.

I knew the voltage would fluctuate, but assumed the job of the inverter was to keep the output level. But, you are correct, this is an $11 inverter...probably too much to expect.

I will try with the headlights on. If I don't find success, the inverter is still valuable for my other devices. I'll get one of the ebay chargers. I was reluctant, as I didn't know the track record of them. Are they generally accepted by the forum community?
 
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Mm mm interesting.

There are two factors that change between having engine running and not.

A) voltage when engine running is up higher to anything from 14v to 15.5v depending on car battery state and what you have also switched on.
B) output watts of the ciggy socket can fluctuate during engine running ...

The DJI unit may be extremely sensitive to fluctuations and its regulator shutting of with them. When engine is not running - the power is smoother and inverter will have better output especially if its a cheap unit. Cheap units are extremely 'dirty' in their output and many items will refuse to work with them.

What happens if you have engine running at steady idle and with headlights on ? This helps some units in smoothing the load .... but not when driving particularly if the alternator regulator is not the smoothest.

Easiest option is to buy a direct car charger for the battery's ... eBay has loads for just a few dollars. Enter DJI battery car charger in the search bar.

Nigel
I think you're all over it solentlife, you can charge lithium iron iPhone batteries in your car and through an inverter, but the technology involved with the phantom lithium polymer batteries is another level. Either buy a quality dc/ac inverter or use the purpose chargers for these batteries. A bloke I recently bumped into had a dedicated solar inverter set up for his drone but the set up was worth more than my car....
 
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There are various ways to solve this.

a) purpose car charger for DJI batterys like I have from eBay.
Or
b) get a general lipo charger that runs of 12v and capable of charging HV lipo's without balance lead connected - which I have.
Or
c) get a better inverter. I have a cheap one as well but that fails on odd items so is rarely used.
 
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My 300 watt inverter acts the same, but if I start the charge with the motor off it will continue to charge even after I start the motor.
 
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From my experience on my narrow boat, a 300 watt inverter is not really of much use at all. I installed a 3Kw inverter and everything worked except the toaster. You just have to bear in mind the load you will be putting on the alternator/battery. BTW the boat had a bank of 5 180Aph batteries. :)
 

AWD

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OK, you guys have gotten my curiosity up on this inverter thing.

I've got one that I've used for years for charging laptops and powering some lights while on the road. Looks like I'll be testing it out on the P4 batteries this week to see how it does.

AD
 
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Well I would assume when your car is running it's using the car battery for power (although should be getting power back from the alternator as well) so the inverter could only use the power available after the car takes it. When the car is off, you should have more power available from the battery.

Also, some inverters I've owned were only rated to a certain wattage with the normal plug. For higher wattage it required direct connection the cars battery.
 
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OK, you guys have gotten my curiosity up on this inverter thing.

I've got one that I've used for years for charging laptops and powering some lights while on the road. Looks like I'll be testing it out on the P4 batteries this week to see how it does.

AD
same same
 
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Seems some are a little confused ....

With car engine running, the alternator will supply the needs of all electrics and charge the car battery. This will mean voltage will be higher than without engine and amps will be as demanded by each item. Therefore there will be more watts available with engine running than without.

The problem is the alternator will be subject to the quality of the bridge rectifier correcting its output from AC to DC to supply the car. Some regulated sensitive items do not like the DC provided and then fail to start. Some units can be started and then engine started and continue but that's unusual.

Inverters come in two forms - the cheap versions where the AC produced is extremely rough and many items will not work, and the expensive variety where output is smoother and designed for sensitive apparatus. They being Modified Sine Wave (cheap) and Pure Sine Wave inverters.

It is generally recc'd that to power a 100W item - you use an inverter of 125W or preferably more.

Be careful when using cigarette lighter plugged items as the max amps many can handle is under 10A, often fused at that. This means a max wattage of about 140W. It is usually better to power by direct connection to the car battery itself.

Inverters are great items but in fact are wasteful in their operation. Let's take this DJI battery op. You are taking a 12v DC supply and stepping up and converting to 110 / 240v AC - then via charger converting back to 17.5v DC. Each step incurs losses and energy loss ....
Better to remove the intermediate AC step and just use a direct DC to DC car charger.

Nigel
 
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We need to be mindful that the 150w (Chinese watts) rating may, and usually is, on the optimistic side. Testing to the extent it is performed will be with 14.4v on the input and driving a purely resistive load at short duration. These ratings should be at least doubled to give any sense of suitability for intended application. I would t be so concerned about the output waveform as the DJI charger will almost certainly have a rectifier on the input, whatever it sees will be converted to DC so line frequency and any harmonics won't effect it.
 
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Sorry but output is a concern as many items such as the DJI brick do care and refuse to work ......

The rectifier on the brick is expecting domestic grade AC input and is built as such.

Refer back to OP statement that it all works with engine off but not with engine on. The Modified Sine Wave form of the cheap inverters alters enough to kick out the DJI brick.

Nigel
 
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Sorry but output is a concern as many items such as the DJI brick do care and refuse to work ......

The rectifier on the brick is expecting domestic grade AC input and is built as such.

Refer back to OP statement that it all works with engine off but not with engine on. The Modified Sine Wave form of the cheap inverters alters enough to kick out the DJI brick.

Nigel
Maybe. A switch mode power supply (the DJI brick being one) will be far more tolerant of a square wave input than a lot of other devices. Just look at the allowable voltage tollerance with respect to input. It will simply vary the duty cycle of the switching devices to arrive at the output voltage. It is more likely that the protection cirncuitry will monitor current limitation on the output. Without knowing specifics the safe explanation is that the cheap inverter isn't up to the task.
 
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At end of day - better to use a purpose made car charger for DJI - loads on eBay for peanut price .... or go better than the DJI brick and get a decent HV Lipo charger such as a B6 mini or Acucel .... wattage is not an issue because the ciggy socket shouldn't be loaded too high anyway.
A B6 mini set at 4S HV Lipo charge mode only with 4A will do very nicely thank you ! And be powered direct from the car socket.

I just happen to have 2 of them and Accucel's .....
Nigel
 
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At end of day - better to use a purpose made car charger for DJI - loads on eBay for peanut price .... or go better than the DJI brick and get a decent HV Lipo charger such as a B6 mini or Acucel .... wattage is not an issue because the ciggy socket shouldn't be loaded too high anyway.
A B6 mini set at 4S HV Lipo charge mode only with 4A will do very nicely thank you ! And be powered direct from the car socket.

I just happen to have 2 of them and Accucel's .....
Nigel
Have you tried the LiPO charge method yet? I haven't. I like the idea though.
 

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