Charging batteries out in the field

[AndersE]

I need to charge my batteries out in the field. First I was think about a gasoline generator with a output of 1000w. Those are not that heavy and they offers more than enough with juice. The other solution would be a 12V lithium battery (LiFEPO4) battery with ~60Ah. No need to mess with gas and completely quite. Being a lithium battery I can use all the power without damaging the battery. I’m planning to connect a 200-300W inverter and then the battery charger for the Phantom.

How many batteries (P3, 4.48Ah, 68Wh, 15.2V) would I be able to charge with a 12V 60Ah battery?

 

[With The Birds]

Just under 7 full charges.

Assuming source battery drained to 80% DOD with inverter and charger efficiencies at 85% (LiFePO4 have a nom cell voltage of 3.25v).

300w inverter may be light on, especially if Chinese origin. I would go for 600w sine wave inverter for reliability.

 

[John Decker]

I seem to renumber seeing that you need a pure sine wave inverter. Of course they're more expensive..

 

[AndersE]

Just under 7 full charges.

Assuming source battery drained to 80% DOD with inverter and charger efficiencies at 85% (LiFePO4 have a nom cell voltage of 3.25v).

300w inverter may be light on, especially if Chinese origin. I would go for 600w sine wave inverter for reliability.

Thanks for the input. I will not buy any cheap inverter. But why are you counting with 80% DOD? LiFePO4 batteries can be used to 100% or close to 100% right?

 

[bobmyers]

Thanks for the input. I will not buy any cheap inverter. But why are you counting with 80% DOD? LiFePO4 batteries can be used to 100% or close to 100% right?

Not right

 

[With The Birds]

Thanks for the input. I will not buy any cheap inverter. But why are you counting with 80% DOD? LiFePO4 batteries can be used to 100% or close to 100% right?

It depends what service life/cycle count you would hope to get. Screw every last bit of juice out of them and get less cycles. 20% is a good compromise.

 

[With The Birds]

From EV Power Systems.

 

[tcope]

As I read it, you are at around $500 for that battery. Why not go with a deep cycle battery?

 

[With The Birds]

As I read it, you are at around $500 for that battery. Why not go with a deep cycle battery?

About $450 AU without balancing circuits and terminal hardware. Advantage is a lot less weight and you can't take lead acid (deep cycle or not) much below 50% without greatly reducing life. I rely on batteries to keep my beer cold in the bush.

 

[tcope]

About $450 AU without balancing circuits and terminal hardware. Advantage is a lot less weight and you can't take lead acid (deep cycle or not) much below 50% without greatly reducing life. I rely on batteries to keep my beer cold in the bush.

$450 and get 7 cycles. I'd either go deep cycle, 4 cycle generator or 3 more batteries. I'd even charge off a running vehicle before I'd spend another $450.

I bought an 4 cycle 800 watt generator off Amazon for $240. It's just a little louder then the Yamaha or Honda. Runs 6 hours on a gallon of gas. It does take longer to charge batteries but it works just fine. I suspect a lithium battery as mentioned would take longer t charge as well.

 

[With The Birds]

$450 and get 7 cycles. I'd either go deep cycle, 4 cycle generator or 3 more batteries. I'd even charge off a running vehicle before I'd spend another $450.

I bought an 4 cycle 800 watt generator off Amazon for $240. It's just a little louder then the Yamaha or Honda. Runs 6 hours on a gallon of gas. It does take longer to charge batteries but it works just fine. I suspect a lithium battery as mentioned would take longer t charge as well.

Will charge just as quick as off the mains if the inverter is good.

 

[AndersE]

The thing is that my boat needs a new battery bank and I'm planning to use the lithium battery in the boat when Im done with the aerial videos. If I can charge 7 batteries I will manage with a 60Ah battery.

 

[Sagebrush]

I spent two days camping last week a long ways from 120 volts. I charged my batteries using a 12V plugin into my camper that was using juice from a Group 27 marine battery. I've got a folding 60 watt solar panel that kept my marine battery topped off.

It worked great.
Amazon.com: BTG Car Charger for DJI Phantom 3 Professional Pro Battery: Toys & Games

The charging is controlled, I believe, by the smart circuit in the battery.

SB

 

[AndersE]

I spent two days camping last week a long ways from 120 volts. I charged my batteries using a 12V plugin into my camper that was using juice from a Group 27 marine battery. I've got a folding 60 watt solar panel that kept my marine battery topped off.

It worked great.
Amazon.com: BTG Car Charger for DJI Phantom 3 Professional Pro Battery: Toys & Games

The charging is controlled, I believe, by the smart circuit in the battery.

SB

How long time does it take to charge one battery?

 

[Sagebrush]

How long time does it take to charge one battery?

I was using about 50%- 60% of the battery charge and it would be topped off and shut down after about an hour and fifteen.

Generators make my ears ring. The thought of charging in the field with 120 volts to get to 12 volts makes my brain spin and my wallet start to squeel. ; )

SB