Can I use the car charger (14v input) with a 16v power supply?

[supernicko]

Sounds a bit odd - but i have a portable car jump starter thats 20,000mAh (can jump start diesel engine up to 5Litre) - small compact battery unit - amazing little device can power the car fridge, charge laptops/phones etc (this is it Jump Starter 900A 20000mAh Backup Power Bank Charger Portable for Car Boat 12V | iTechworld )

it has 12v 16v and 19v - the 12v got the Mavic 2 battery to 75% full and stopped - a bit like when the car isnt running and i thought the battery unit was stuffed - turns out its got 16v and 19v option for laptops.

I know nothing about power/voltage etc. so wondering if i stick it on the 16v option will the charger (its got a transformer inline with the cigarette charger thing from DJI) will it just draw down 14v and be ok?? i imagine its designed for some fluctuation as car power supply may change a bit from 14+ when its running down lower when the car is off?

I didnt work out this thing had a 16v - so i had it on 12 and ended up just running the car to charge her up (2 at a time as the car has a small inverter too so i ran the 240v and the 14v cigarette charger too)

Keen to know before i fry a $250 battery

 

[cyeung]

What are you using to connect this battery pack to the Mavic battery pack?

 

[Kilrah]

Should be safe to try, you'll see soon enough if the charger considers that OK or refuses to charge. No risk for the battery.

 

[waylander]

Hi supernicko
I use an old lead acid golf cart battery ( 12.5 -13.5 volts when measured with AVO meter), I carry the battery in the trunk of the car ( saves having the cars ignition turned on ).
This battery will charge all 4 mavic pro batteries when used with the MP car adaptor.
But I notice that as the golf cart battery gets closer to a discharged state, it will stop charging the MP's battery.
I put this down to the MP's car charger, I recon that as the doner battery's voltage gets closer to 12.6V the MP's adaptor cuts out.
This I think is due to the fact that a single cell LiPo has a nominal voltage of 3.7 volts ( 3.7 x 3 =11.1 volts) in a fully charged MP battery each cell will measure 4.2 volts therefore 4.2 * 3 =12.6 volts, so if the doner battery drops below 12.6 volts the MP charger cannot continue charging.

Nominally a lead acid car battery is around 13 volts, theoretically it should be 2.1 x 6 (cells) = 12.6 volts, but fully charged they are generally 2.25 volts per cell = 2.25 * 6 = 13.5 volts so the more discharged it becomes the less likely it is to continue charging via the MP car charger

I would be reluctant to use your battery pack using the 16 volt setting, it might cause the MP charger to overheat.

Good Luck
Waylander

 

[Kilrah]

Firstly this is about Mavic 2, not Mavic 1.
Secondly the charger stops not because voltage is too low to charge the battery, but becasue it's designed to cut pretty early to avoid risking discharging your battery to a state where you're not able to start the car anymore (and a bit too much on the safe side).
Thirdly the MP car charger supports 24V as well (not the MP2 one though).
Fourthly these things are protected, no risk of "overheat". If things are out of spec it just won't run.

 

[waylander]

Firstly this is about Mavic 2, not Mavic 1.
Secondly the charger stops not because voltage is too low to charge the battery, but becasue it's designed to cut pretty early to avoid risking discharging your battery to a state where you're not able to start the car anymore (and a bit too much on the safe side).
Thirdly the MP car charger supports 24V as well (not the MP2 one though).
Fourthly these things are protected, no risk of "overheat". If things are out of spec it just won't run.

Yes I was talking about the Mavic Pro car charger, but I think the same will hold true for the Mavic 2

I did not know that the M2 charger was dual voltage 12 v and 24 v inputs, but non the less the M2 car charger will sense the input voltage, so if it is using a 12 volt ( nominal ) supply it will I think still cut out as described in my post at around 12.6 volts. if connected to a 24 volt battery then it's fully charged voltage will be 2.25 * 12 = 27 volts, but the nominal cell voltage will be 2.1 * 12 = 25.2 volts.

If as you say the Mavic 2 car charger cuts out at a predetermined input voltage level to protect the vehicle's battery then how will the M2 car charger react to a voltage of 16 or 19 volts both are higher than 12 and less than 24 volts.

 

[rickw]

I think with jump starters like you have when you go up in voltage the wattage output is lower,I might be wrong but I don't think at 16 or 19 volts you have enough amperage,might damage your jump pack

 

[Kilrah]

I think the same will hold true for the Mavic 2

It is not correct and you did not read my post correctly, the M1 charger supports 24V, not the M2 one.

If as you say the Mavic 2 car charger cuts out at a predetermined input voltage level to protect the vehicle's battery then how will the M2 car charger react to a voltage of 16 or 19 volts both are higher than 12 and less than 24 volts.

I don't know, and that's why I told OP to simply try. It is not risky since it's protected anyway and will just not charge if it considers that voltage inappropriate. I would only try 16V and not 19 since it's not rated for 24V operation.

I think with jump starters like you have when you go up in voltage the wattage output is lower

No the wattage is same, but amperage is lower. The charger also draws less when the voltage is higher obviously.

That jump pack does not give any spec for the 16V output, but it's supposed to be protected (better be at this price, seems to be about twice of what a similar thing usually goes for).

 

[supernicko]

Wow thanks guys for the detailed replies and thoughts. I did first try using my second car battery (dual battery set up in the Landcruiser) and the second is dedicated to the fridge and charges on BCDC charger due to a modern variable output alternator. I suspect the fridge drawdown was probably pulling the battery down a fraction hence was ok to run fridge - just no good for 14 odd Volts.

The pack is rated at 8amp but that is only labelled on the 12v output. The 16v and the 19v are meant for laptop power supplies so i made some assumption that they would have the same amps out (i havent googled volts vs amps vs wattage etc yet!)

I drained a bit off a battery and tested it - the 16v output via cig lighter plug then lights green - the battery reacts does one spin but then it cuts out (the light on the DJI transformer goes out, then back on then cuts out again) - maybe the amps on the 16v side is pizz weak - ill call the MFR tomorrow and ask. The 12v side reacted a bit like you said waylander - it just didnt quite top it off (was about 75pc charged) and just stopped there.

The car has a basic inverter 240v but only works while motor running - and thats only rated 100w - that powers the standard power pack just fine which is rated 240v/1.8amp. Just prefer not to run the motor for an hour while i juice the packs - i was thinking this little power pack would double nicely to top off 3 batts.

Thanks Waylander i might have to consider the battery spare when camping with drone - i was lucky it was windy and couldnt really hear the car humming away - a nice quiet evening this would have annoyed my mates i think.

If all else fails i may just have to pop the bonnet and direct connect to the main car battery which is likely to get me 2-3 batts charged - then if for some reason the car wont start i do have the dual batt and then also the 900VA crank starter!
RE: PRice - we do cop it here in Australia - though there is one for $99 aussie dollars - that does 10,000mAh and 400VA cranking - but i got the bigger one incase a mate is stranded with a bigger V8 diesel motor (of which there are alot of diesel 4x4 out here!) so not sure how that compares with intl marketplace - mine was $199 AUD. (about $145 USD)

 

[supernicko]

What are you using to connect this battery pack to the Mavic battery pack?

it connects via the car charging kit that comes with the fly more - the battery pack has a cigarette lighter style adaptor.

 

[waylander]

It is not correct and you did not read my post correctly, the M1 charger supports 24V, not the M2 one.


I don't know, and that's why I told OP to simply try. It is not risky since it's protected anyway and will just not charge if it considers that voltage inappropriate. I would only try 16V and not 19 since it's not rated for 24V operation.


No the wattage is same, but amperage is lower. The charger also draws less when the voltage is higher obviously.

That jump pack does not give any spec for the 16V output, but it's supposed to be protected (better be at this price, seems to be about twice of what a similar thing usually goes for).

I'm sorry sir, but I could say the same to you about reading and UNDERSTANDING the concept put forward in the my post, I'm not arguing the semantics, M1 M2 Mavic Pro, blah blah, it is the principle of switched mode power supplies that i am trying to convey, sorry if the concept is too difficult.

 

[Kilrah]

I drained a bit off a battery and tested it - the 16v output via cig lighter plug then lights green - the battery reacts does one spin but then it cuts out (the light on the DJI transformer goes out, then back on then cuts out again) - maybe the amps on the 16v side is pizz weak - ill call the MFR tomorrow and ask.

Yep, looks like the 16V output isn't powerful enough.

I'm sorry sir, but I could say the same to you about reading and UNDERSTANDING the concept put forward in the my post, I'm not arguing the semantics, M1 M2 Mavic Pro, blah blah, it is the principle of switched mode power supplies that i am trying to convey, sorry if the concept is too difficult.

It's very simple, but the point is that it's completely irrelevant in this topic.
What's driving the "works or doesn't work" has nothing to do with how a switching power supply works, it only has to do with what upper and lower voltage thresholds DJI have hardcoded into their car charger. They are documented at least for the M1, I had actually measured and posted these for both 12V and 24V myself long ago. If you're in those ranges it works, you aren't it doesn't. Easy as.

 

[waylander]

Yep, looks like the 16V output isn't powerful enough.


It's very simple, but the point is that it's completely irrelevant in this topic.
What's driving the "works or doesn't work" has nothing to do with how a switching power supply works, it only has to do with what upper and lower voltage thresholds DJI have hardcoded into their car charger. They are documented at least for the M1, I had actually measured and posted these for both 12V and 24V myself long ago. If you're in those ranges it works, you aren't it doesn't. Easy as.

Yep like I said..... Ta tah

 

[Kilrah]

No.
You said:

This I think is due to the fact that a single cell LiPo has a nominal voltage of 3.7 volts ( 3.7 x 3 =11.1 volts) in a fully charged MP battery each cell will measure 4.2 volts therefore 4.2 * 3 =12.6 volts, so if the doner battery drops below 12.6 volts the MP charger cannot continue charging.

But it has nothing to do with this, the thresholds are solely defined on the input side for car battery underdischarge protection.
Oh and MP batteries charge to 13.05V, not 12.6.

 

[waylander]

No.
You said:

But it has nothing to do with this, the thresholds are solely defined on the input side for car battery underdischarge protection.
Oh and MP batteries charge to 13.05V, not 12.6.

Sorry Sir but you just don't read what is written do you, or you fail to understand the language, please read my post again.