How to kill your battery or P&G at night...
 

My first foray into increased FE has been a seat of the pants attempt at P&G. Since I work 3rd shift there is rarely anyone else on the road and I've been gliding down to 20-23mph.

After 2 tankfulls my battery died. It has taken a charge again but it is clearly weaker than before, I don't think it'll make it through a VT winter. All of a sudden LED tail/dash/headlights seem very practical and I'm dreaming of deep cycle batteries.

In the meantime I'm doing a tank of 40mph max under power and coasting down hills, engine on. This may be the plan for the winter anyway, since the car also produces almost no heat from the heater during P&G, no big deal at 50 degrees F, but 28 F was chilly.

What else can I do to bump the FE without spending an arm and a leg?

How old is the battery?

Good question, I bought the car used a year ago and while the battery definitely
isn't original, I'd say it's a good 3-5 years old. Maybe it is its time to go anyway.

When you've done P&G what did you do to reduce strain on the battery?

Oh, I murdered my (then) 1 year-old starting battery over a year ago. :)

But not from P&G directly - I've been running without the alternator. I've since put in two 6v golf cart batteries to run things.

Deep discharges are brutal on starting batteries. If you want to minimize the impact, minimize the discharge depth (which varies by time & load).

I would say that typical P&G isn't a big problem for battery longevity, because the glides are typically not very long (minimizing discharge).

Deep cycle battery
Engine block heater
Grill block
Warmer clothes (particularly snow pants)

I too killed my 10 year old original battery in my Geo shortly after trying engine off coasting. Since replacing it almost a year ago, I haven't had any problems with the new one.

Mmm, 2 golf cart batteries? Now that's an interesting idea...

bump start instead of using the starter when beginning a pulse might help a little.

:thumbup: I was bump starting, it was just the lights, defroster (off as soon as I could see), wipers (ditto), and the radiator fan (which I almost put a kill switch on)

Leftovers from forkenswft?

I think your right about P&G during the day, but at night I guess my electrical load was pretty high. Maybe next time I should learn to use my multimeter before I kill the battery.:o

What type of block heater are you using?
The grill block is coming!

But snow pants? Mine are leftovers from Ski Patrol, bright blue, my kids call me "the streaking smurf" when I wear them.

I'm gonna get the factory job that costs $22 for the heater... and about $400 stealer installed unless my independent-mech can do it much cheaper and we can get the proper install procedure.

Don't scoff at snow pants... I could motorcycle all winter long (max exposure time would be 45 minutes) in my youth in Ontario by wearing an old down filled set of air force flight pants.

If you want to / need to get extreme with the frigid P&G stuff you may want to think about a breathing device that will allow you to expel your moist warm breath somewhere other than near an ice cold windshield.

I replaced all the running lights on my car with LEDs, the headlights are still stock. It saved about 65 watts while improving visibility slightly. Only cost about $45 from superbrightleds.com

65w is a big drop! Are LED headlight still just vaporware?

65 watts, wow...perhaps I will finally do this!

Yeah, it's nice. The 65w savings also includes replacing the license plate lights and removing two rear sidemarker lights. When the brakes are on, I get an additional 90w savings which is especially helpfull since I typically have the engine off when using the brakes.
They have LED daytime running lights, but they're not as bright at real headlights used for night driving. IIRC the brightest LED is equal to a 25w headlight.

LOL! Sorry, not at you. I had a benz whose heater fan died, hence I had no heat. I had to exhale into a grocery bag, let the moisture freeze, then let the air out. I can only imagine what people thought in traffic....:o )

If nothing else I'll be getting a dipstick heater soon, I'd prefer a recirc style but I'm so dang tempted to sell the car.

I did LEDs too, figured it was 70 to 100 watts saved. Also have a trolling battery now. There is a bag of whites on the desk right now I plan on making into headlights/drls when that project gets to the top of the list.

FYI, my flasher spazzed out without all the load, so I took the flasher apart and set it up on the bench and touched a small electrolytic capacitor across the existing capacitors one at a time in parallel (that increases the capacitance) till I found one that responded, then experimented with different capacitor values till I found a value that gave an acceptable blink rate. Then it was soldered it to the existing capacitor and close it up (and reinstall it).

Can you post up pics of this and what value cap you used? I've tried finding a flasher that didn't have the fast blink on a burned bulb feature, nothing yet. Had LEDs on the wife's work rig she used to deliver mail, since the heat from the factory setup kept blowing the bulbs and melting the connectors due to her being on the brakes all the time. I never did find an acceptable flasher, and wasn't willing to order one for 30 bucks since the only downside was the bulbs flashed faster. Nothing real special about that setup, just got some semi trailer bulbs and screwed them to the oudside of the tail light housings. Appearance didn't really matter on it, just that it worked. The only thing stopping me from going LED on the nice vehicles is the flasher issue, and I didn't want to use the resistor load pack that keeps getting recommended since that defeats half the purpose of going LED.

So... to recap this thread:
 

1) P&G at night (engine off, lights on) can kill a battery, seems like we've all done it. (on the bright side I killed a crappy old one)

2) there is a lot that can be done to reduce the strain on the battery during glides:
2a) turn off all that you can. radio, fans, rear window defogger, wipers
2b) find (install) ways to turn others off. i.e. radiator fan, etc.
(my lights dim when it kicks in... never noticed before)
2c) led replacements seem to be cost effective, just wish I could do headlights too.
2d) bump start rather than use the starter to restart after glide

3) replace battery with deep cycle (any recommendations on a cheap one?)

4) grill block, block heater and warmer clothes are more FE that running the motor to stay warm. Crack windows under 30mph and it works well to defrost windows. And keep the inside of the car DRY. Get the snow off your feet before you get into the car. Get a warm day? Vacum the moisture out of the carpet.

5)an ignition/injector momentary switch is a really good idea since you don't loose your lights while shutting down the engine. (which surely will attract the local jandarmes.

>"5)an ignition/injector momentary switch is a really good idea since you don't loose your lights while shutting down the engine. (which surely will attract the local jandarmes."

I hadn't thought about that. I do some EOC at night, I'll have to be carefull.

Another tip to save a few more watts is to use the dimmer switch to turn down the dash lights. They are still quite visible at half power. I added up all the power that the dash lights require and it came out to around 80-90 watts. I figure it's another 40w saved for free.