JoeS
Site Moderator
Posts: 3480
Joined: Thu Dec 15, 2011 5:47 am
Location: Los Altos Hills, California

Re: 12v Accessory Socket Power Draw

Fri Nov 25, 2016 7:25 pm

Just to clarify, we've drifted off-topic as those power levels require a direct connection (via a fuse) to the 12v basttery. With inefficiencies, that 300W(ac) inverter means somewhere around 30A at 12v.

Once again, for the 12v accessory outlet, we're suggesting that the maximum steady-state current out of it should be somewhere around 5A, say 60W maximum.

Talking about PowerPoles and the accessory outlet ("cigarette lighter outlet"), I have one of these adapters and quite a few pigtail connectors which do the same thing and are much cheaper:
https://powerwerx.com/cigbuddy-cigarette-lighter-powerpole-adapter
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

Benjamin Nead
Posts: 126
Joined: Tue Nov 08, 2011 10:21 am
Location: Tucson, Arizona, USA
Contact: Website

Re: 12v Accessory Socket Power Draw

Mon Nov 28, 2016 8:05 am

Just to clarify, we've drifted off-topic . . .


We have, Joe? The "topic" (which you already changed once) was, as far as I can see, safely running an AC device, such as an audio power amplifier, off of the vehicle's electrical system. A full discussion on this topic shouldn't be limited to just the accessory socket (ie: what used to be called the cigarette lighter back in the day.) Perhaps it's appropriate to - again - change the topic heading to reflect this? I'll leave that to you and PV1.

Here's a recap . . .

I inquired if running an 60 watt per channel stereo (combined total 120 watt) audio power amp from the accessory port, which is labeled to able to accommodate that exact wattage. I further inquired about two possible inverter choices. I was advised that, while the port is labeled such, the limitations of the interface meant that attempting to draw anything beyond around 5A would be risky.

It was then suggested that I might want to consider a separate tap from the 12V battery and terminate with Anderson connectors. I'm fine in pursuing this sort of modification and the talk turned to ("off topic?") the practical concerns of what gauge of wire to use and how this could accommodate a more powerful inverter that the 120 to 150W ones I originally envisioned.

Next, the conversation turned to the idea of running an far more powerful inverter, as it's been observed that the vehicle's traction battery is capable of supplying up to 900W when the car is turned on (ie: "Ready.") But, if I'm reading PV1 correctly, this is something that I could only do for 10 minute periods. That doesn't sound like something I'm particularly interested in trying.

I'm also questioning the value of the most recently linked item: the "cigarette lighter" plug with Anderson outputs. If the port itself is the compromising factor in safely accessing the 12V battery's fullest potential, it seems somewhat pointless to insist on passing through that port and onto a set of connectors that are more robust . The "a chain is only as strong as its weakest link" adage would seem to apply here.

So, yes, I suppose I'm wanting to focus on the "off topic" idea of, say, 12 gauge wire directly from the battery, inline fuses (or fuse,) the wires passing into the cabin and then terminating on 30A Anderson pins.

Questions I still have . . .

1) What's the procedure for attaching the wiring to the battery? What size lugs are on the i-MiEV's GS Yuasa's 12V/32Ah unit? Is it advisable to loosen the the bolts on the sides the the terminal clamps and inserting lugs through there? Or should I completely remove the terminal clamp/wire assemblies and slip larger lugs underneath there and reattach? From what I understand with any sort of modern computerized cars (i-MiEV included,) doing the latter would require a trip to the dealer to reset the dash warning light (if not something even more involved and expensive.)

2) Is it necessary to fuse both negative and positive wires? I'm assuming just the positive one would do the trick. With the above described battery/wiring scenario, is a 30A fuse (or fuses) recommended, or should it (they) be of a smaller value?

Final adage of this post "the only stupid question is the one that didn't get asked."

:)
Benjamin Nead / Tucson, Arizona, USA
Secretary: Tucson Electric Vehicle Association (EAA chapter)

North American 2012 i-MiEV SE / Pearl White /CHAdeMO
Aka: "The Vanilla Jellybean"
Purchased used in Nov. 2015 @ ~18,000 miles

JoeS
Site Moderator
Posts: 3480
Joined: Thu Dec 15, 2011 5:47 am
Location: Los Altos Hills, California

Re: 12v Power Into Main Cabin

Mon Nov 28, 2016 8:58 am

Benjamin, point well made and I changed the title again. Don't forget, your original post was in the 12v battery thread rather than one about utilizing that 12v power.

To answer your questions:

1. Good practice (e.g., as required by marine wiring) says to place the fuse within 6" of the power source, in this case the battery. I attached my in-line fused wire directly to the battery terminal clamp using, if I remember correctly, a 5/16" lug (but since it's a 10mm nut then a 1/4" dia. terminal should fit the 6mm stud). No need to remove the large terminal: just take the nut off and slip the wire with its ring termination onto the stud and put the nut back on.

2. Only the (+) side needs to be fused. The fuse size should be appropriate to the wire size, wire length, and load that you plan on using. I have 30A on my #12AWG wire which is only about 8" long between the battery terminals and the Anderson connector. Here's a handy table I just found:
http://www.sunforceproducts.com/Support%20Section/Solar%20Panel%20&%20Charge%20Controllers/WireGaugeSelectionTable.pdf
(their watts at 12v doesn't make sense)
Edit: here's a better link: http://www.westmarine.com/WestAdvisor/Marine-Wire-Size-And-Ampacity

Another Edit: if you don't want to make your own, here's a gold-plated ready-made harness with fuses in both the (+) and (-) legs: https://powerwerx.com/ring-terminal-powerpole-inline-fuses-10-gauge
You could then attach the wire going to the cabin to this Anderson connector (I would lower the fuse size to match your wire and load), thus giving you the ability to disconnect under the hood and use a different accessory (e.g., a battery charger) if needed.
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

PV1
Site Moderator
Posts: 2917
Joined: Fri Apr 27, 2012 4:22 pm
Location: Pittsburgh, PA
Contact: Website

Re: 12v Power Into Main Cabin

Mon Nov 28, 2016 9:24 am

I drifted off-topic myself, but after Joe's post, I went back and corrected it.

What I meant is that the car must be READY if you want to use the accessory port for more than 10 minutes at a time. You'll want it READY anyway so that the 12 volt battery doesn't go dead. With the car READY, you can use 12 volt power until both the main and 12 volt batteries go dead, which will take quite some time with a total load of 300 watts (accessory draw plus ~200 watts vampire from the car itself) drawing from the drive battery.

Leaving the key in ACC (car is off except for radio and accessory port) means that power drawn only comes from the 12 volt battery. The DC-DC converter isn't active. In READY, it is, so all power used actually comes from the high voltage drive battery.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013

"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015

2017 Bolt EV LT in Orange with QC - 7/31/2017

Driving electric since 2-21-2013.

Benjamin Nead
Posts: 126
Joined: Tue Nov 08, 2011 10:21 am
Location: Tucson, Arizona, USA
Contact: Website

Re: 12v Power Into Main Cabin

Mon Nov 28, 2016 9:25 pm

Splendid, guys. Much appreciated for all the info. I don't have a timeline on this project and it might not happen until after the new year. But now I have a good basic plan.
Benjamin Nead / Tucson, Arizona, USA
Secretary: Tucson Electric Vehicle Association (EAA chapter)

North American 2012 i-MiEV SE / Pearl White /CHAdeMO
Aka: "The Vanilla Jellybean"
Purchased used in Nov. 2015 @ ~18,000 miles

Aerowhatt
Gold Member
Posts: 408
Joined: Wed Jan 28, 2015 1:52 pm

Re: 12v Power Into Main Cabin

Tue Nov 29, 2016 9:08 am

Benjamin Nead wrote:Splendid, guys. Much appreciated for all the info. I don't have a timeline on this project and it might not happen until after the new year. But now I have a good basic plan.


Alternately, I found that the best place for me to put an Inverter was in the little storage bay (rear passengers side cargo area). It was simple to connect the positive wire where the DC out on the cars charger unit (in the motor bay). By removing one of the child car seat attachment lugs I was able to have a bolt hole to run the positive cable up into the trunk and under the trunk mat to the passenger side cubby (without drilling). The inverter itself is a 300 watt pure sine wave unit which is mounted with SS zip ties (again no holes drilled in the car). The negative lead of the inverter is tied to a good existing ground (don't recall exactly where but it is very short). The hole that the pos wire comes through is sealed with a dab of silicone caulk and the wire is fused 3 inches from the cars charger DC out connection with a water resistant ATO fuse holder.

It works with or without the key.
Wire runs are short.
Full inverter power, Including surge, is available.
Tested the inverter and it will shut itself down leaving enough power in the battery to go to ready mode with the key!
This attachment point is a direct connection to the 12V battery in front.
when not in use the inverter is "stowed" out of site and out of the way.

Aerowhatt
2014 cool silver ES, acquired new 4/2015
2014 Labrador Black Pearl ES, acquired new 3/2016

PV1
Site Moderator
Posts: 2917
Joined: Fri Apr 27, 2012 4:22 pm
Location: Pittsburgh, PA
Contact: Website

Re: 12v Power Into Main Cabin

Tue Nov 29, 2016 9:45 am

Since it would now be on-topic, here are a couple of pictures of my inverter install (no, it's not a bomb :mrgreen: ):

https://www.dropbox.com/sh/hwp6neikv9gr ... LqZ7a?dl=0

Inside the box is a Black and Decker 100 watt direct plug-in inverter (no cord) with the plug removed and the connector soldered directly onto the board. There is also a step-down converter to drive the fan at a low speed. The noisy fan inside the inverter was removed, replaced by the large fan that moves 5 times more air and is almost silent. This inverter powers the Playstation 2 hidden in the rear compartment. Power was tapped from the radio's main feed (yellow wire). Likewise, it will run regardless of the key position, but I haven't tested its shutdown point. I control it with the red rocker switch I installed as part of my LED upgrade (used to control the red accent lights, but the dimmer is now used for that).

I only went the inverter route because it was cheaper than an isolated DC-DC converter for the PS2, and isolation is necessary because of disc motor noise on the head unit.

So, there are a few different options for getting auxiliary power in the cabin with higher amperage than the stock accessory port.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013

"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015

2017 Bolt EV LT in Orange with QC - 7/31/2017

Driving electric since 2-21-2013.

Return to “Instruments - Radio/USB/Nav - CAN - Climate Controls - Remote”