Max cigarette lighter inverter question

I inherited an old Montgomery Wards 12VDC/6VDC battery charger/tender from my father when he passed away ...My dad bought it in the early 1970s... I've been using it for years ... but infrequently... the last time I used it was about four years ago. IIRC it is not suited to run anything because of its low current output but it is just right for recharging a battery. For access to 12vdc emergency power - the challenge is to matchup a 12vdc inverter that will not shorten the lifespan of the Prius' aux 12vdc battery(36 Amp-hour, ? 100% duty cycle) which cost over $100 + labor to replace. ISTM the key factors are the inverter's fuse, max/peak current load, and sustained current load. I've been also looking at the portable battery jump starters too ( because hybrids can't give a jump start without alot of *extra work* to protect their inverters- a separate portable battery jump starter would be a faster solution) - Early reviews by Consumer Reports suggest many of these devices don't work as promise and they are often quite heavy so the adjective "portable" is used in this context loosely.

 

This is a little bit dangerous advise ... do this on a not fused connection can REALLY damage many thing not the least just the wiring ... in case pump shorts for example...also the nominal current charging the 12V battery is 4.2A !!!

I would absolutely not recommend this to anyone who is not familiar enough this stuff and asked this question ...

So I would say by spec your pump is (plus inverter) exceed the currents should go through the battery ... or any of the 12 V port ...

Of course this may just be fine for inflating one mattress ... but generally dangerous....

 

It is not the voltage but the current you can pull not much ... the cig connection is 15A I believe the theoretical max is just about 2 hour (from the battery alone) on that draw and you just got yourself a potentially dead 12 V battery ... car will not start and it cost about 200 dollar ... DO NOT DO this. Note that unless the car is in Ready you have no power in the cig adapters for very GOOD reason .....

If the car is on Ready you can SAFELY plug-in an inverter in the cig adapter by spec 15A give or take 160W on the that end after inverter loss (good ones 10% ) 150 W ... but that is it ... if you use something with power spikes you can blew the fuse easily .... it is important to understand that if the inverter is rated higher it WILL try to draw more .. and will be a problem ...

You can find real interesting project tapping into the HV battery which is a totally differint ball game you can get 10/20x times this power ..... which can support your house and it is a LOT more efficient then those walmart generators (but again that is a different level project) ....

 

What's the big deal if the inverter itself has a fuse?

Since we know the cigarette lighter circuit has a pretty low amperage limit (and would very likely blow its fuse to charge the OP's air mattress), a bunch of people have gone well beyond it by hooking to the 12 volt battery directly and being in READY mode. Have you looked at threads such as the ones I posted in posts 4 and 10? There are many others.

 

The inverter has a fuse -IN THE CIGARETTE LIGHTER PLUG-. The ONLY unfused part would be the "pigtail", which is about a foot long. It's perfectly safe. I build my own, and put a fuse within a few inches of the battery plus terminal. So I'm paranoid.
But if you want to be paranoid too, that's fine.

Do note that cigarette lighter plugs are not really the -best- way to connect to power. They tend to be a bit resistive in their connection and will heat up, potentially melting eventually (they are plastic). So I prefer to use proper connectors (I use a two pin Molex one, sockets on the supply side, pins on the loads that plug in).

 

OK I missed the point of the plug itself has a fuse in it (my mistake then) I was trying to point out NOT to use simple jumper cable or something similar to that.

 

There are some really easy to start/easy to use small generators around nowadays. Just put stabilizer in the gas (it's good for up to two years) and you're good to go.
After what happened in DC last week- I decided to give my 5500 watt gen it's summer run. Started first pull and ran flawlessly! I think I paid around $600 when I bought it 5-6 years ago. Having the generator (and extra gas around) and a roof antenna that pulls in NYC stations gives me peace of mind during storms...

 

My inverter has a fuse in the unit itself. It's a 40 amp fuse right above the screw terminals for either the cigarette lighter or jumper cables.

 

A comment from the future, for others who are browsing:
* We have a Gen3 2011 Prius
* I wasted too much $$ on cig lighter inverters. They all require a fan, which is noisy, and dies. Totally useless.
* Got the $150 Xantrex ProWatt 600W inverter, with the remote status/switch. Mounted the switch in the console, inverter under front passenger seat, and (huge!) cables + big fuse back to the 12V aux battery.
* We have a power strip in both front and back of our car. Plenty of plugs to recharge laptops, cameras...and run our little mini-fridge.

It's been a decade. Zero issues. Amazingly, the inverter fan has either never turned on, or is so quiet we don't notice.

And our AGM battery is still the original.

 

Hi MrPete! Thanks for sharing your success with this setup. I'm completely new to the world of inverters and since I have the same year you have, I am glad to see this information. If I purchase that inverter, are there any separate components I need to also purchase to be able to make a setup like yours? Thank you for any info!

 

I went back and reviewed a few things.
It's the ProWatt 600 SW, with the remote switch.
See p10 of instructions for fuse/power cable recommendations. Min 80W ANL fuse, and they recommend size 0 cable. Huge, yes... but we're talking a lot of amps. You want to size the cable based on how you will route it. Mine goes from middle of the front passenger seat front edge, to the door (under the carpet), then under the door jamb, passing through to the back of the right-rear seat along the wall -- not interfering w/ the HV battery module... and to the side-mounted fuse box I added (I think using heavy double stick tape?) and then to battery...

Here's my actual ordered items (found it!)
Scosche EWFH Single ANL Fuse Holder
DB Link ANL150 150 Amp ANL Fuses
Cobra CPI-A4000BC 4-AWG Heavy-Duty AC Power Inverter Cable Kit

IMPORTANT note: officially, there is NO WAY a Prius AGM battery should support a lot of watts on the 12 volt battery. I will just suggest: don't turn this on if not in Ready mode. it's a great way to need a call to AAA