# Difference Between Wall Outlet and 12v Car Inverter?

#### Newusaa

Joined Mar 4, 2018
15

#### Alec_t

Joined Sep 17, 2013
14,370
But can I use an inverter in my car plugged into the cigarette lighter, and plug battery’s charger into that to charge the battery while I drive?
It would depend on the construction of both the charger and the inverter. Some devices (possibly the charger) can't tolerate non-sinusoidal input voltages. Is your inverter output a genuine sine-wave, a so-called 'modified sine-wave', or merely a square-wave?

Edit:
How long are your road trips? Your charger output is rated 3.5A. Even if it could supply that continuously without stress, to charge a 1276Wh battery from empty to full would take (1276Wh/48V)/3.5A = 7.6 hours in an ideal world. In reality, the battery would be damaged if it were totally empty to start with, and the charger might not be happy providing 3.5A for lengthy periods.
If your car has 12V electrics then the inverter would need to draw at least 3.5A*(48V/12V) = 14A from there. What is your cig lighter current rating?

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#### sagor

Joined Mar 10, 2019
914
Most cigarette ports are rated for 10A only, (120W). You cannot run a 180W charger from that. You would have to run an inverter directly off the battery and it should be rated higher than 180W (maybe 300W inverter). Make sure you have a means to disconnect the inverter from the battery, else it will drain it over time even when idle.

#### Tonyr1084

Joined Sep 24, 2015
7,943
One thought - maybe outrageous but - - - add a second alternator to your vehicle. Modify the control voltage from 12 to 3 volts and you should get a good 48 plus volts out of it. If the alternator is a 30 amp charger you should be good to go. Outrageous because that involves a lot of mechanical work.

Once you've gotten all that done you'll need a way to control the charge rate of the Li-Po battery. Get that wrong and you're not going to have a battery for long. Possibly even a loss of the vehicle.

#### Newusaa

Joined Mar 4, 2018
15
I feel like I’m in over my head already. These are insanely expensive batteries. Maybe just be better to buy more battery power and charge only at home.

I don’t have the inverter yet, I was looking at which one to buy today.

The charger says something like “110-240v input”. So if I give it that through an inverter, it won’t work? I guess my question is how do you know crunching these numbers where you go wrong. How can it possibly not work if youre giving the supplied charger what it needs?

#### Newusaa

Joined Mar 4, 2018
15
It would depend on the construction of both the charger and the inverter. Some devices (possibly the charger) can't tolerate non-sinusoidal input voltages. Is your inverter output a genuine sine-wave, a so-called 'modified sine-wave', or merely a square-wave?

Edit:
How long are your road trips? Your charger output is rated 3.5A. Even if it could supply that continuously without stress, to charge a 1276Wh battery from empty to full would take (1276Wh/48V)/3.5A = 7.6 hours in an ideal world. In reality, the battery would be damaged if it were totally empty to start with, and the charger might not be happy providing 3.5A for lengthy periods.
If your car has 12V electrics then the inverter would need to draw at least 3.5A*(48V/12V) = 14A from there. What is your cig lighter current rating?
Ironically if those numbers are right it’s perfect. My drives are about 6 hours.
Idk what my cig lighter is unfortunately

#### ThePanMan

Joined Mar 13, 2020
800
Idk what my cig lighter is unfortunately
Typically 10 amps.
The charger says something like “110-240v input”. So if I give it that through an inverter, it won’t work?
Depends on a lot of unknown factors. Pure Sine wave, modified sine wave, square wave. Depends on what your inverter can handle. Will it work? I don't know. If the inverter requires more than 10 amps then you can't just plug it into your cigarette lighter, it would have to be directly wired to the battery or a switched source that can handle sufficient current for the inverter. Forget to shut the inverter off (in the case of direct battery wiring) will drain your battery.

As for the charger being compatible from 110 to 240VAC, that just means you can plug it into either US or European electrical grids. US typically runs on 110VAC at a standard outlet. European is typically 220VAC. The charger can be plugged into either. As I understand it - Japanese electric grid is commonly 100VAC. If the charger isn't rated to run on that voltage then you would need a different charger.

I once thought of having a lighted truck shell powered from an isolated battery. The idea was to keep the battery charged via parking lights. That didn't work out so well. I had caused myself electrical issues. Maybe I did something wrong , I don't know. But doing it right means paying attention to a lot of detail.

I sort of like Tony's idea of a separate alternator, but now you're messing with the control voltage, and that can be anywhere from tricky to dangerous. Don't know if I'd go that route. A lot of mechanical work - IF you have the room for a second alternator. And if you do all that work and the project is a bust - that's a lot of wasted money. Why waste all that cash and hard work?! Or even risk it. The potential for catastrophic failure, especially with a LiPo battery is just too great to ignore.

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#### Newusaa

Joined Mar 4, 2018
15
Typically 10 amps.
Depends on a lot of unknown factors. Pure Sine wave, modified sine wave, square wave. Depends on what your inverter can handle. Will it work? I don't know. If the inverter requires more than 10 amps then you can't just plug it into your cigarette lighter, it would have to be directly wired to the battery or a switched source that can handle sufficient current for the inverter. Forget to shut the inverter off (in the case of direct battery wiring) will drain your battery.

As for the charger being compatible from 110 to 240VAC, that just means you can plug it into either US or European electrical grids. US typically runs on 110VAC at a standard outlet. European is typically 220VAC. The charger can be plugged into either. As I understand it - Japanese electric grid is commonly 100VAC. If the charger isn't rated to run on that voltage then you would need a different charger.

I once thought of having a lighted truck shell powered from an isolated battery. The idea was to keep the battery charged via parking lights. That didn't work out so well. I had caused myself electrical issues. Maybe I did something wrong , I don't know. But doing it right means paying attention to a lot of detail.

I sort of like Tony's idea of a separate alternator, but now you're messing with the control voltage, and that can be anywhere from tricky to dangerous. Don't know if I'd go that route. A lot of mechanical work - IF you have the room for a second alternator. And if you do all that work and the project is a bust - that's a lot of wasted money. Why waste all that cash and hard work?! Or even risk it. The potential for catastrophic failure, especially with a LiPo battery is just too great to ignore.
Yeah. Thanks everyone. If I was going to spend that kind of money in car mods I could just buy extra batteries to charge at home and be way better off.
so what may happen if I tried this setup with a ”good” pure sine wave inverter etc? I guess you may need more info to answer. But it sounds like I’m going to pass on this entire idea. they do have some solar charging option available but the gear gets expensive fast

#### tindel

Joined Sep 16, 2012
937
So does your boat not have a gas generator and/or motor to charge batteries? Or is this an electric boat or sail boat?

#### Newusaa

Joined Mar 4, 2018
15
So does your boat not have a gas generator and/or motor to charge batteries? Or is this an electric boat or sail boat?
Yeah I’ve been planning on it being an electric boat but am slowly changing my mind. Too difficult to charge, the batteries are very expensive and they are gigantic

#### Boggart

Joined Jan 31, 2022
82
Yeah I’ve been planning on it being an electric boat but am slowly changing my mind. Too difficult to charge, the batteries are very expensive and they are gigantic
Why not just fit a couple of solar panels to the boat, or a small wind generator like an ampair, they are pretty common on sailboats for keeping batts topped up. But, solar will put out a lot more power, you should be able to fit a few hundred watts on most reasonably sized boats.

#### tindel

Joined Sep 16, 2012
937
You need a boat slip and a high voltage outlet available in your boat slip, similar to an electric car. Then you need a battery charger to plug into the outlet. This would allow you to have a range of travel just like an electric car.

Note that charging your batteries with a gasoline car negates any “green” benefits. Also note that sailing is the ultimate in green energy travel. Perhaps the best ever. Biking is also up there and promotes healthy lifestyle.

A small solar array or wind generator on board will give you the ability to charge your battery in an emergency. Don’t expect these methods to keep your boat traveling continuously however Volkswagens used to come with a small solar panel to plug into the cigarette lighter in an emergency.

I’m a power engineer by trade. If you were to put space grade solar panels over the entire body of a Tesla you would extend the range of your car about 10%. It’s just not worth the cost, time, and complexity.