Civic EPES: Alternator Delete Project (with additional lithium battery...)

[brucepick]

This project has been built and is in daily use. Some finishing touches remain to be done.

Below are a serious circuit diagram and detailed notes. Plan on much more than a quick look if you're interested in building this or something similar.
Circuit drawing, as-built
Project circuit notes
(These are .pdf files; you'll need Acrobat or another .pdf reader to view them)

Daox asked if I have pics.
I took a few last weekend, haven't had time yet to get them up to photobucket for sharing.
Hopefully the circuit diagram and notes in links above will be more informative than a handful of pics.

[deathtrain]

thanks for the PDF's but now my questions are:

1) was it worth it?
2) what type of gains are you seeing?
3) Do you have a alternator kill switch? (I know the answer but I would like to spell it out for the others who have not read the whole thread.)

[California98Civic]

Originally Posted by deathtrain

thanks for the PDF's but now my questions are:

1) was it worth it?
2) what type of gains are you seeing?
3) Do you have a alternator kill switch? (I know the answer but I would like to spell it out for the others who have not read the whole thread.)

Agreed deathtrain, these are important questions. I think suggestive evidence is already available. If you study his fuel log across the last couple months there is an unmistakable improvement since the mod. That's not proof, but it is suggestive. He notes the number of EOC miles in his notes too. He seems to be averaging a 10% gain. In my alt delete I have felt I was getting a 5% gain (Brucepick and I have quite similar cars, as you probably know).

[brucepick]

Was it worth it? Well, I'm an OCD fuel economy fiend so if I can increase mpg, I'm a happy man. I got a $260 "jump" on the overall cost from the money I got when I junked my old Volvo 240. What I didn't face at the start was that the whole cost would run between $600-700, far more than what I got for the Volvo. The battery was $459 + charger about $45 + about $50 shipping, if I recall. Plus cables, and some money to my buddy to run it from engine bay to the rear interior area.

Yes, nearly 10% gain in the four most recent fills. My last fill, not yet in the log, is about 53.x mpg so not quite 10% but still very nice. I think that will go up again, after I deal with weather-related changes - lean burn issues due to too much grill block for this warmer weather.

Yes there's an alternator cut. I put a disconnect switch on the main battery + terminal. The switched side of switch goes directly to the alternator [not via starter], so I can have the alt connected or not with a quick trip under the hood. The [other] side of switch goes to the battery + and to the starter, so starter is always powered by the main battery. The old oem wire from starter to alt is disconnected at the alt and taped over. If you haven't studied the circuit diagram, just understand that the new LiFePO4 cell + terminal is wired to the main fuse box from where it powers the car's electrical system. However it doesn't power the starter, as noted just above.

I first attempted an alternator cutoff by disconnecting the small four wire "control" connector at the alternator. Within a couple minutes of startup, it was putting out 14V anyway, charging the battery. So I had to resort to disconnecting the alt's main output wire instead, at the alternator. I left the control wires connector disconnected also, no sense powering the field coils etc. if I'm not running it.

[California98Civic]

I figure at 10% FE gains at $4/gallon and 20,000 miles a year you'll save about $144/year. But you seem maybe to drive more than 20K a year and gas prices are going up. Treated well, your pack may well give you back all its cost over its life. Your hypermiling will absorb the rest of the cost soon enough. I'm grateful you shared so much of your process and information. It has helped me with mine. You have to love what you drive. And you have to love modding to do mods like this. Cool.

[EDIT: And this summer your savings will be amplified. I bet to break 70mpg in three tank or 90 day averages. You may get $200 a year in savings, which would greatly reduce the amount of time for payback.]

[Daox]

Pictures?

[brucepick]

Originally Posted by Daox

Pictures?

Ask and ye shall receive. Though I think you first asked about 2-3 weeks ago!!

[If you're not logged in you won't see the pics; you could go here to see them: Civic Alternator Delete Project pictures by brucepick - Photobucket]

View of battery and fusebox, with new cables and alt cutoff switch:

From left, clockwise:

• Purple wire entering main fuse box replaces the oem one that was connected to battery +. Trace through taped-over connector to red wire exiting right side of pic, it goes to the lithium pack. Small red wire at the connector powers MPGuino, and the headlights and horn via added relays.
• Ground cable
• Black wire at rear of brass plated switch, going to right and down: Via a fuse on firewall, it next joins the red wire via a switch located behind drivers seat. This is my "jumper"; connects the lead starter battery to the to the lithium's red output cable. If lithium's ground is cut via another switch, this powers the car via the lead "starter" battery. Mainly used to support charging the lithium with no load of computer/radio/clock/MPGuino on the lithium while charging. Also supports other functions; see the circuit drawing & notes in link in first post of this thread.
• Black wire at rear of brass plated switch, going forward + downwards: OEM starter wire. Note that OEM cable from starter to alt is removed at the alt so this wire does not go to alt.
• Purple wire at front of brass plated switch, exiting right side of pic: Goes to alternator + output terminal. This is normally switched off here; can be switched on if alt is needed for any purpose.

Closeup of alternator + switch area:


OEM battery cable (spare from junker) with new connector. Note notches cut in connector; these fit the fitting at alternator's screw terminal.


New connector prepared:

Note bend in connector; new cable approaches the alternator from above. This approach angle also makes for better access to remove the 4-wire alternator connector.

Two switches and the charging connector, located behind driver's seat on floor:

• Three-wire switch is the "jumper switch" mentioned in first pic above.
• Two wire switch is the lithium pack's ground disconnect.
• Not very visible, but the white charger connector has an unusual blade/slot configuration. I put a matching male connector on the charger's cables. These are from Home Depot; 15A rating exceeds my charger's 10A output. Enables quick connecting of the charger and no likelihood that either connector will be plugged into a 120V AC circuit in error, by anyone.
• I plan to mount the switches on a project box to keep things more neat, and to position the knobs upward for easy access.

Front view of the two switches:


View of the lithium power pack in trunk, with connections to its + and - cables, and the 200A fuse:

The white loop at top end of pic is a lift grip for battery; it has a twin at the other end of battery.
The fuse and holder are ANL size. These have much larger contact area and much better current carrying capability than blade type fuses of any size, to the best of my knowledge. Commonly used in high end car audio systems.

[brucepick]

I finally got the deep cycle battery properly secured in the trunk. These photos should be mostly self explanatory but I'm sure I'll find a few words to add...

Remember this battery pack weighs only 16 lb. The aluminum framing is certainly up to the job of holding it in place.

Aluminum 1" x 1" x 1/16" square tubing in place

The three screws into the trunk floor are #8 sheet metal screws. The six others are 1/4-20 bolts with nuts + lock washers. You also see a 1/4-20 threaded rod with nylon-insert lock nut on the back side.

Battery secured in the framing

J-hook rods are pretty standard for battery holddowns. However with cramped access and the rods going sideways into the 1x1's it was much easier to set up a locking nut on the back side of a threaded rod.

The pack is 7 3/4" long, more than the width of than a typical automotive battery. So I needed the adjustable black plastic bracket, at its maximum length.

Trunk flooring back in place, laid up against side of battery

[steffen707]

Awesome man! How much did the lithium pack run you? Where did you get it from? Sorry if you already posted that earlier. I just got your PM and read the wiring diagram post.

[brucepick]

Originally Posted by steffen707

Awesome man! How much did the lithium pack run you? Where did you get it from? Sorry if you already posted that earlier. I just got your PM and read the wiring diagram post.

Thx.

Details on the lithium pack should be in this thread if you search. Kinda pricey; about double the cost of a typical Optima or Odyssey battery. But at least their chargers are less than Odyssey chargers, about $45 each.