The 12V socket is unlikely to be limited to 0.5A. Use a multimeter to get the real value.

Most 12v cigar lighter sockets tend to produce 10A @ 12V, some special ones 15A, but you need bigger cables for 15A. My suggestion is to wire up a 12v connector to whatever input method your charger uses (most seem to use XT60) and make sure the polarity is correct. Check the XT60 (or whatever you used) with a multimeter after you built it to make sure + and - are correct. I suspect that 12V socket will produce enough amps for a mobile air compressor to run, so 10A or thereabouts.

That USB socket could be useful for charging 1S Lipos (via a parallel charger), or if you can find a Volantex 2S USB charger, 2S Lipos as well.

(25-Jun-2023, 10:37 PM)aerokam Wrote: Here is the back label of the jump starter:

https://i.imgur.com/ns1k04Sl.jpg[/img]

It looks like the 12V outlet is limited to 500 mA, so not gonna work.

Any way to adapt the jump starter cables to an XT60, or am I just pushing it?

That 500mW is for the AC wall socket adapter which I assume comes with the unit so you can charge it up from the your house 110V mains voltage supply. The "DC Accessory Outlet" just states 12V with no current rating, so who knows what current it can supply. I bet it has piddly thin wires soldered / connected to the back of the cigarette socket which means the current capability is going to be limited by those alone, and the probably have PVC sheathed wires which will melt and potentially catch fire if you try to draw too much current through them.

It's a bit of a ghetto solution but just have an XT60 with two wires coming from it with bare stripped / tinned ends. Then clip the jump start croc clips to the bare wires. Obviously be careful to get the polarity correct !!

A 12v motorcycle battery is what I would use if I didn’t trust the 12v aux plug in or was afraid for my electrical system. Unplug the battery if you aren’t charging. One of the guys that flies here uses a modified jumper cable to whatever DC input his charger uses. He also has a jumper pack if his vehicle battery ran down and wouldn’t turn over his starter.

He hasn’t flown at the field in a few weeks so I can’t vouch to what the set up is

My Jeep is a manual so a simple push will get me running

(25-Jun-2023, 10:58 PM)SnowLeopardFPV Wrote: That 500mW is for the AC wall socket adapter which I assume comes with the unit so you can charge it up from the your house 110V mains voltage supply. The "DC Accessory Outlet" just states 12V with no current rating, so who knows what current it can supply. I bet it has piddly thin wires soldered / connected to the back of the cigarette socket which means the current capability is going to be limited by those alone, and the probably have PVC sheathed wires which will melt and potentially catch fire if you try to draw too much current through them.

It's a bit of a ghetto solution but just have an XT60 with two wires coming from it with bare stripped / tinned ends. Then clip the jump start croc clips to the bare wires. Obviously be careful to get the polarity correct !!

Thanks. I don't remember getting any AC adapter with it. There's a male 2-prong input that I just plug an extension cord into to charge it. I was puzzled what the AC adapter was all about.

So there normally wouldn't be some sort of current limiter that limited the output current to whatever the unit could handle?

The adapter at Amazon is cheap, so I'll get it and see how it works. I'll also try the ghetto solution--I have several XT60 connectors with leads, so that's easy to try.

We've been 100% EV since 2017, so I have no use for it as a jump starter anymore. Last time it was put to good use was when my daughter borrowed it to go camping some years ago. Her battery tended to die on her longer outings, and they also used it to charge their cell phones. We keep it just as an emergency cell phone charger in case of power outages. Figured I might put it to some use if possible.

Seems like this was more or less solved, but in case other people are looking for a reasonable solution you can also get a battery tender, which is basically alligator clips with a specific plug on the end -- and you cut the head off and replace it with an XT60 and you've got yourself a decent method of charging right from a standard car battery. Just always be sure to stick around and keep an eye on things just in case things go sideways.

(25-Jun-2023, 10:55 PM)Pathfinder075 Wrote: The 12V socket is unlikely to be limited to 0.5A.  Use a multimeter to get the real value.

Most 12v cigar lighter sockets tend to produce 10A @ 12V, some special ones 15A, but you need bigger cables for 15A.  My suggestion is to wire up a 12v connector to whatever input method your charger uses (most seem to use XT60) and make sure the polarity is correct.  Check the XT60 (or whatever you used) with a multimeter after you built it to make sure + and - are correct.  I suspect that 12V socket will produce enough amps for a mobile air compressor to run, so 10A or thereabouts.

That USB socket could be useful for charging 1S Lipos (via a parallel charger), or if you can find a Volantex 2S USB charger, 2S Lipos as well.

Cool.

I ordered the 12V to XT60 connector, and it arrives today. What if I just use the cable to connect the jump starter DC outlet to my HOTA D6 Pro AC/DC dual smart charger (AC 200W DC 650W 15A), then connect one 6S 1100 mAh battery to see what happens? Then connect a second one if it seems OK with the first?

Will there be some sort of current negotiation between the power supply and the charger, so the charger doesn't try to draw more current than the power supply can supply?

What if I do the same with the jump start cables? Will the charger limit the current to whatever it can handle?

Here's what ChatGPT says:

Prompt: I want to use an adapter cable to connect my 12V 500A jump starter to my 15A dual channel LiPO charger. Will the charger limit the current to whatever it can handle, or could I damage it?

Response:

Quote:The charger should, in theory, limit the current to what it can handle, but it also depends on the specifics of your charger and its protection systems.

Chargers designed for LiPo batteries typically include safety features that limit the input current to prevent overloading and overheating, and they should also have overvoltage protection to prevent damage from a too-high voltage source.

However, connecting a 12V 500A jump starter to a 15A dual channel LiPO charger could potentially pose a risk if the charger's safety features fail or are insufficient for that level of current. Even though the voltage matches, the potential current supply from the jump starter is much higher than the charger's rated 15A current. This could overload the charger if the charger's safety features don't work correctly.

Always consult your charger's manual or contact the manufacturer if you're unsure about what sources of power are safe to use with it. Improper use can result in damage to the charger or battery, and may even pose a fire risk in severe cases.

Also, it's crucial to note that the rated output current of the jump starter (500A) is likely the peak, not sustained, current, and it's designed for short bursts of power to start a car, not for sustained power delivery to a battery charger.

Overall, it's best to use a power supply rated at an appropriate level for your specific charger to avoid any potential issues.

Prompt: What about using the 12V DC outlet on the jump starter? I assume that the current is no more than 10A, but don't know for sure. What if it cannot supply enough current to charge two 1300 mAh 6s batteries. What would happen?

Response:

Quote:If you're using a 12V DC outlet from the jump starter, the supplied current is indeed usually less than what the starter can provide for jumping a car—commonly in the 10A to 15A range, but you should confirm this from your jump starter's documentation.

If the current supplied by the jump starter is not enough to charge your batteries at the rate your charger is trying to charge them, several things could happen, depending on the charger and the power supply:

1. The charger might just charge the batteries more slowly. This would be the best-case scenario.

2. If the charger tries to pull more current than the jump starter can supply, the voltage might drop. This could cause the charger to display an error, or it might turn off to protect itself and the batteries.

3. In a worst-case scenario, if the charger continues to demand more current than the power supply can provide, it could potentially cause the power supply to overheat and possibly damage the jump starter or even create a fire risk.

Most good-quality chargers should have protection against low voltage input and should shut off or display an error in such cases. However, always check the documentation and specifications of both your jump starter and your charger to be sure. If in doubt, contact the manufacturer or a professional to avoid potential damage or safety hazards.

Just bear in mind that a jump starter is designed to produce lots of CCA but probably doesn't have the biggest sized battery.  So maybe a 40-50Ah.  You need to work it out, as 50% of that capacity is what you should use at the most.

Yes you could connect the jump leads to the 12v connector if it has croc clips or plugs (tape them if using these to stop the two sides touching/arcing).  Do not let the two terminals touch, the worst case if they do is the battery explodes, which would mean A) shrapnel, B) sulphuric acid and C) some sort of sulphorous gas, probably hydrogen sulphide (egg smell).  None are a good thing.

Another suggestion.  Put an inline blade fuse in between the positive jump lead and 12v lead going to the charger.  To work out the size of blade fuse, work out how many amps the charger will pull at 12V and round that up to the nearest sized fuse.  So probably you'll end up with say a 15A fuse or 20A fuse. If something goes wrong, the blade fuse will pop before you have a fire.  If you decide to do this a lot, get a proper midi or mega fuse and build something specific.

Basically the charger will use whatever the limit of it's power input is.  So for example, say 100W @ 12V = 8.3A, so if you put a 10A fuse in between the jump lead and the charger, if it ever decided to try and pull more amps than it should do the fuse would pop.  This could happen if the charger overheated and maybe went into some sort of thermal runaway type situation where by some components got cooked and it just started pulling as much power as possible, but having the fuse inline means the second power requirements go past the size of the fuse it will pop and break the connection.


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