You guys and gals saved my bacon this weekend with your tips and tricks. Thank you.

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I drove down the coast this weekend for a long weekend, so 3 days of camping, and some amazing new places to fly.
Sadly, I left the battery chargers sitting at home :(
I have 5 batteries, and 3 of those are semi-dodgy DJI originals, that I already consider suspect and don't use a lot, or use with great caution, but had to risk it with them because I was going to need every battery I had and then some to get through 3 days.
Then I remembered someone here mentioned that the smart charger is actually built into the battery, so the battery really only needs a source of power greater than 11.1v and it should charge.
I decided the dodgiest of my old DJI batteries could be the Guinea Pig, and so I grabbed a length of wire, stripped the ends, and improvised 2 power leads off the car battery and shoved them into the battery's charging holes. Turned the battery "on" and it immediately started charging.
It never seemed to actually "finish" charging, but once the 4 lights had flashed for long enough, I did a test flight, and it was showing 100% and seemed to discharge at a normal rate (got 15 minutes 44 seconds flight time to the 20% mark off it).
In the end I did the same to all 3 DJI batteries and they all responded similarly, except one only ever showed 89% charged, and the other 97%, none of them went to 100% the way that first one did. But they all seemed to fly just fine, with reasonable flight times, and the usual expected speed of discharge.
I can't say I'd advise making a habit of it, but if you're ever really really stuck and HAVE to charge a battery without a charger, you could try shoving 12 volts into it (place the "positive" into the left side hole, and "negative" into the right side hole) and turn the battery on.
 

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Didn't know that ! Cool and glad ya got your flying time in !! Wish
ya hadn't put Bacon in your topic though cause you know TJ !
He be looking in here now cause he can smell it ! Be all like .....
the rock..nod.gif
:eek:
Is a great tip and just took a Red Sharpie marker and put a + on the left side as I will sure enough forget that part !
How long did it take to charge one like that ?
 
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Good idea, if you're in a pinch or a bind.
Not something I would try, but glad to learn, it worked out well for you..
What gauge was the wire, if you know?

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"You guys and GALS saved my bacon this weekend with your trips and tricks. Thank you."

There are gals here?
 
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dirkclod

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"You guys and GALS saved my bacon this weekend with your trips and tricks. Thank you."

There are gals here?
I saved one's first avatar bro as I liked it !
25944.jpg
Now here face is her avatar ;) and there's a bunch more.
Ya not paying attention Clipper o_O
 
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I sure am glad TJ didn't know about this while he was on holiday. I heard he forgot his charger and his skivvies.
 
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No, I planned on leaving my skivvies home, leaving the batteries at home was an accident. I remembered last weekend and the wind never let up. I'll just try again next weekend. I can't wait to post a video of camp!
 

dirkclod

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No, I planned on leaving my skivvies home, leaving the batteries at home was an accident. I remembered last weekend and the wind never let up. I'll just try again next weekend. I can't wait to post a video of camp!
Make dang sure ya have them skivvies on ! :eek:
 

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dirkclod

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Yes, BMS protected P2/3 battery packs will charge off a cigarette/accessory 12VDC outlet or similar.

Ideally, a current regulated supply is better but the pack BMS would likely protect it from over current and of course max over voltage.

But, do not attempt this with regular old P1, RC Lipo 3S packs/bricks. Nada, nada, nada….
 
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dirkclod

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Yes, BMS protected P2/3 battery packs will charge off a cigarette/accessory 12VDC outlet or similar.

Ideally, a current regulated supply is better but the pack BMS would likely protect it from over current and of course max over voltage.

But, do not attempt this with regular old P1, RC Lipo 3S packs/bricks. Nada, nada, nada….
Never stop learning stuff in here ! Thanks guys !!
I guess If ya had a spare connecter from an old charger ya just could wire it up and leave it in ya kit for need more juice moment's !
 
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Never stop learning stuff in here ! Thanks guys !!
I guess If ya had a spare connecter from an old charger ya just could wire it up and leave it in ya kit for need more juice moment's !
Or get a charger intended to provide 15v from a 12v battery to run a laptop to charge p3 batteries. Probably only 60w but that is enough.
 
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Not sure how long they took, I know it was quite a while, but that was partly because they never actually turn off and say they're finished, they just stay lit up (pretty sure from memory they stopped flashing, but stayed lit up 4 solid leds) but all were still lit up even after a couple of hours, so I'd swap over another one whenever that happened. I was only prepared to risk my 3 DJI batteries, so easily got them all done during dinner and the sit around the fire afterwards.

Fortunately, I also found one of my torches uses the same 12v plug as my Black Pearl too, because that also died on me during the weekend. It died mid flight while my bird was down out of sight at the water's edge, at the very end of this promontory,
Brou Lake 007n.jpg

and I was over 500m away at the start of the walking track. MAN THAT STOPS YOUR HEART - I was 500m away, and not 100% sure which way the bird was facing when the screen died, and it was below the line of cliffs. Had to hold my breath, tell myself not to panic ... a moment's pause, then decided that because the winds were quite strong, RTH might not be the best option to try straight up, and that the best FIRST option was a blip on the throttle to get it up over the cliffs again, and then use Home Lock and just pull back on the stick.
I gave it TWO good blips on the throttle just to be sure, then full reverse on the stick, and sure enough she came sailing back straight to me (at about a 45 degree angle) and at exactly about the height I'd guesstimated she'd have reached from the two bursts on the throttle. Boy was I happy to hear that buzz getting closer. And VERY glad to find I could charge the monitor/receiver with the torch charger.

I hope NEVER to leave home without chargers again, but just in case, I'm thinking of cannibalising one of those really cheap bars you can buy on ebay that allow you to plug in multiple batteries at once, and just keep one of them, or even just the plug part of one of them, in the car wired up ready to go if I do ever forget again.
Here's about where I was flying from when it was just below the cliff line at the far end:
Brou Lake 009.jpg
 
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dirkclod

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I love those moments when their over !! Make's ya know ya alive eh ! :D
When I was young I liked a buzz and still do but a different one :eek: ;)
 

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