12v/24v Cigarette Plug Directly To Battery

So you decided to add a 12v plug directly to your battery in the trunk. 

This plug is ten feet long.  10ft long.  Extra cigarette port.  A.k.a. 12 volt plug port for charging.  Far more power also.  
    10 foot length is not long enough to reach the front but it's more than halfway.  It can get the job done if you have a plug cable able to reach as far back to the front seat headrest.  See below how I wasted space to get that far it is actually hanging halfway down the front seat back.  See pic.


Here it is with the eb3a cable.

The 12v cigarette plug is all the way in.
You can just barely see the metal strip but it is flat inside all the way looks like it is bulging and not all the way in.  Like with the Cobalt's 12v ports it seemed to not go all the way in but on this plug it is in all the way and mostly appears to be all in.  Could be deeper just because.


Hanging between headrest halfway down front seat with this 10ft long cable.

Has ring connection at battery posts simply screw them down under the bolt holding the battery terminals down on each side black then red is how I did it (I know nothing).  The wire reached the front seat over the top of it coming through the rear seat split.  Likely want 12 foot to reach front console or 14 to reach front passenger floor board.       However, I am going up and over the trunk baggage and then through top of seat so if do a straight pass laying flat would get to center console near the hand brake I suspect.

Getting 100 watts to eb3a.  102 to 103 with car running.  
Drops to 35 mainly but saw it at 47 watts when not running when first turn off engine then drops to about 35 watts.
    It's about as much power as a solar panels worth of power to my power station at 100 watts.  Could be 147 watts is the EB3A cap anyways.

The Bluetti EB3A (discontinued) in 2026 now.

It's a 600watt, 268Wh power station ((this is how much power it can output from the battery charge it has in total it's 268 watt hours of power at peak 600 watts (things like laptops use 40 watts not 600 continuous FYI) but it can momentarily do more as in when an appliance first starts could be 1000 watts to start then less running it)).  Likely won't start a microwave and be able to run it if it could handle the surge spike.  Need more watts and more surge power on start up so eb3a is good for laptops, etc... mini fridge.  [Link]
      Has AC and DC power option and the USB connections.  AC as in wall outlet and DC for cigarette lighter 12v plug port.  The AC uses an "inverter" so that draws power to use so it is best to use the 12v cigarette port for DC power.  If shopping items to use look for those that come with both cables types.
        Can be charged with wall, cigarette or solar panel.  MPPT plug port.  You can't plug a cigarette connection to input to it to charge, instead the cigarette plug goes into the cars cigarette plug then there is the MPPT plug port on the eb3a.  Little circle plug hole.  You can output from the eb3a with a cigarette connection in top left for DC power that is plugged into the eb3a then into your tech.  To charge off the eb3a or as a pass through if getting wall or solar power or direct from battery.  The lower left is the port to charge the eb3a with solar or cigarette and then the wall AC cable plugs into the square looking cover on the port.  Need to lift  see picture above.

In about ten minutes got 8% charge so from 1% to 9%.  At 100 watts.  Has a 30A fuse, one connected near the battery in a little storage box inline and 2 spare.  It's up to 17% in time took make this blog post.  So 20 minutes.  

The socket is 10mm and a ratchet for install.  Battery is located in the right rear of trunk under floor panel lift it up.


See the black ring connector screwed down on battery terminal.

Cable coming through rear seat from trunk.

The item I got on Amazon:

The YCIND Store on Amazon
4.6 out of 5 stars (454)

3/8" Ring Eyelet Terminal to Female Cigarette Lighter Socket Battery Boost Cable Heavy-Duty 30A Fuse 12V/24V 12AWG Cord 10Ft

The 12awg is the size of the wire.  Could be 14 or 10.  Etc... AWG is "American Wire Gauge."

The 3/8" ring eyelet is the size of the circle metal holes that fit on the battery posts.  Might be mine here are too large slightly maybe a size smaller than 3/8 would work but it seems right.  The screw holding it down perfectly fits the ring to cover it as the ring is so wide and screw is also so bulky at the base they mate right to cover the eyelet, but in terms of the ring around the battery screw post it is loose in fact could be half the size hole in the eyelet ring.  (But I don't know anything).
    The size of wire is important because thin cable wires transfer less energy so get hot when put lots of power through it gets hot or melts or pops a fuse, hence larger wire less heat.  Better conductivity.  
  The cobalt's cigarette ports can't charge the eb3a due to power draw pops the fuse under hood.  Made post about it.  The high port in center console is slightly less power than the one by the hand brake allegedly.  [Link]

Here is link

https://www.amazon.com/dp/B07KR6WKD5?ref_=ppx_oui_title_mob_b_fed_asin_title_0_0


30A amp fuse.

Grok AI:

Here’s what you need to know about using a 12V cigarette-port cable connected directly to your car battery to charge the Bluetti EB3A.
Official Specs & Expectations
The EB3A’s DC input accepts 12–28 V, max 8.5 A / 200 W.
The official car charging cable is short (≈28 in / 72 cm), 16 AWG, with a cigarette-lighter plug on one end and DC7909 on the other.
In real-world use from a car’s 12 V system you typically see 50–100 W (often closer to 60–90 W), not the full 200 W. At ~12–14 V the theoretical max is around 100–120 W before the unit’s limits and voltage drop kick in. Higher voltage (engine running, alternator charging at 13.5–14.4 V) usually gives better input power than a resting battery.
Critical Safety Points for Direct Battery Connection
Connecting the cigarette cable directly to the battery bypasses the car’s fused cigarette socket, so you must add protection yourself:
Inline fuse is mandatory — Install a fuse (typically 10–15 A, slow-blow or automotive blade type) on the positive wire as close as possible to the battery terminal (within a few inches). Without it, a short circuit can melt wires or start a fire. Do not rely only on the car’s main fuses.
Correct polarity — Positive (usually red) to battery positive, negative to battery negative (or a solid chassis ground). Reverse polarity can damage the EB3A or trip protections.
Wire gauge & length — The stock 16 AWG cable is fine for short runs. Longer cables need thicker wire (12–14 AWG recommended) to reduce voltage drop and heat. Thin or long wires will limit charging power and can get warm.
Secure, insulated connections — Use proper ring terminals, heat-shrink, or Anderson/Powerpole adapters if possible. Avoid loose clips that can short against metal.
Heat monitoring — Check the plug, cable, and connections after a few minutes. If anything feels more than mildly warm, stop and investigate (poor contact, undersized wire, or high resistance).
Best Practices While Charging
Run the engine (or have the alternator active) for anything beyond a short top-up. Charging with the engine off will drain your starter battery and can leave you stranded, especially in cold weather.
Place the EB3A securely so it can’t move or become a projectile. Keep its vents clear for cooling.
You can use the EB3A’s outputs while it charges (pass-through is supported).
Charging temperature range for the EB3A is roughly 0–40 °C (32–104 °F). Extreme heat or cold will reduce performance or stop charging.
Monitor the EB3A’s display for input watts and any error icons. If input stays very low, check voltage at the DC7909 plug (it should stay above ~12 V under load).
Limitations & Tips
Car charging is a convenience / backup method, not the fastest. AC wall charging or solar will be quicker when available.
Some users report better results with a quality DC-DC booster (raising voltage toward the higher end of the 12–28 V range) while staying under 8.5 A, but this is optional and requires careful setup.
The cigarette plug itself can be a weak point (loose fit, contact resistance). If you hard-wire often, consider converting to a more robust connector (Anderson Powerpole, etc.) with proper fusing.
Bottom line: It works and is commonly done, but treat the direct battery connection like any high-current automotive mod—fuse it properly near the battery, use adequate wire, keep polarity correct, and prefer charging while the engine is running. Follow those rules and the setup is reasonably safe for occasional or moderate use. If you’re unsure about the fuse/wiring details, have someone familiar with automotive electrical work double-check it.