The "I'm not a hybrid" hybrid idea
 

Having a fairly long commute each day, I have time to think through some different ideas to improve my mpgs. I know that an alternator delete can make for a pretty substantial improvement, but I am pretty nervous about doing it. A 45 mile commute, each way, is a long distance. Even if I bought a deep cycle battery, I'd be worried about getting stranded.

That said, I saw people talking about a DC-DC converter here a couple of weeks ago. Cool, now I can string a couple of batteries together in series, mounted in the trunk, run a DC-DC converter outputting ~14.5V and delete the alternator. But it seems a shame to have a battery pack and only to delete the alternator.

But here's where my cogitating went: What if I added a couple more batteries and used it to power a small motor mounted in the current location of the alternator? Could I disconnect the motor's drive pulley and use the motor to drive the accessories?

Okay, what's wrong with this idea? Surely I'm missing something.

Sure, you could do this... or you could just delete the accessories... unless one of them is a belt-driven smog pump or something similar.

If you absolutely have to keep the A/C, you could drive that from a e-motor, but you could also just attach the e-motor to it, in place of the clutch assembly that's already on it.

You could then use the clutch assembly to freewheel the PS pump until the steering wheel moved more than a few degrees from center, where it would trigger a contact strip that would engage the A/C clutch driven PS pump.

I still +2 on just deleting the accessories, removing the starter, going with an e-motor and a toothed belt that will put out about 10HP for 30 seconds, and blocking the IACV on the engine.

This will mean that you use the e-motor to start moving from red lights, any time you come to a complete stop or clutch in for long enough, the engine stalls. That way, you don't have to worry about turning the key off, then back on, etc... you just leave the key on, the gasser stalls, the e-motor takes off for you when you press the button, and the gasser is driven by it, so it will start on it's own when the RPM's are high enough to allow the engine to run without external power. (right around 300 RPM, the engine will run, but won't create useable power until nearly 500-750 RPM, which is crawling in first gear.)

Imagine how much gas you won't be using when your engine doesn't run at red lights or any time you come to a complete stop, and the e-motor is doing all your <10MPH driving...

Why would you need/want a DC-DC converter, if you're (I assume) using standard 12-Volt lead-acid batteries? Either hook them up in parallel (for twice the run time) or have an A-B switch so that when one is drained, you switch to the fresh one.

B/c your car doesn't run on 12V, even though they're 12V (nominal) batteries.

Carlos knows a thing or two about this set-up.

Plus, your e-motor would be more efficient and powerful at a higher voltage, say, a golf car motor or Etek at 36-60V

DC-DC is the only way to do an alternator delete right. Your electrical system really needs ~14v to do its thing. I once read that a race team measured a 10hp drop for each volt below 14.5v. If I simply disconnect the alt in my camry it only takes a minute before the battery voltage is ~11v with a load on it. It still runs fine, but the spark isn't as hot, lights are dim, fans run slower, etc.

I've found a dc-dc on ebay that takes 24v and outputs 13.8v @ 60 amps cheap ....should be perfect for an alt delete. Combined with a small AGM for cranking and to handle peak loads like a radiator fan kicking in and you'll be at least 10% better. On my camry its more like 20%, which is pretty phenomenal.

Instead of removing the alt you just de-energize the field. Its easy to do....and if you ever drain the batteries or have some problem you can always just re-activate the alt in a second.

Frank -

Me? All I have is a solar panel with a trickle charger :

http://ecomodder.com/forum/showthrea...html#post55639

It does look like Sunforce has lots of other charge controllers for batteries :

SunForce Products Inc. -


CarloSW2

Electrocharger?

Does a water pump count? And yes, A/C is quite necessary. I minimize how much I use it, but 100F heat with 98% humidity is quite intolerable. I've sweat through shirts, front and back trying to avoid the A/C.
I suppose I could just find a different location for my e-motor, but that seems more complicated than simply removing and replacing the alternator if I'm in a bad situation.
Actually, yeah. That's a good name for it. It does boost available engine power, doesn't it?

I'm not convinced about the need for 14 volts, if folks here are already making more mpg without the alternator, then isn't that the point? Have any of these folks said it was a problem? Most every electrical component I know has some degree of tolerance, and alternator (and belts) do break.

I would definitely test that theory before buying a DC-DC converter, but use fillup to fillup data and not instrumentation. Changing the system voltage WILL affect your injector pulse length, your cars computer should be able to handle it though (that is reflected in the pulse length change).

Plus all your cars lightbulbs will probably last forever :)

dcb, I think you're correct about the ECU being able to compensate. But orangeboy's experience says that the voltage does make a difference in FE on an alternator-less system.

A/C does not need to run nearly as fast as the engine, so it could be put on an electric motor by itself. The drag of the motor through the electrical system, assuming you keep the alternator to power it, will be substantially less than directly connected to the engine.

Water pump -

Depends on the vehicle as to whether you have to design it in to your plans.

Most cars with timing BELTS have the water pump driven by the belt, so you don't have to compensate for it at all. (It's still a power drag, though, and there are WP delete kits that relocate your Tbelt and run the pump w/ an e-motor for some cars. Honda comes to mind.)

If you already have an electric water pump, you can get an electric one, a kit to make it electric, or just leave it belt driven. It's one of those things that you don't want to do without, for sure.

If you have a fear or running out of charge, you can always use a starter/generator motor to do what you're suggesting, so that you can just reverse the field and it will charge instead of drive, but you'll still have to have a way to mechanically link it to the crankshaft of the engine. (Like another belt.)

Maybe your car doesn't, but all of mine (excluding the Insight, of course) have run just fine on 12V, as for instance engine-off coasting, or when an alternator goes out.

Yah, I'm not sure OrangeBoy is convinced either :) Anyway you will increase the demands on your battery if you increase system voltage and reduce your "range". Applying more voltage means your electrical components will draw more current.

If your car works fine without it, and there is a range and cost penalty with it, I'm having a hard time understanding why it is there.

I'm just aiming to maintain the same voltage as currently supplied by my alternator and battery. I'd much rather keep my headlights as bright as they are now (the difference between the luminosity at 14.5 and 12V is probably directly proportional to the voltage and 17% is an awful lot of light).

Christ, you may be right about my water pump being driven by the timing belt. But I think it is driven by the serpentine, or so one of the moderators at Corolland.com said. The picture of the water pump at autozone seems to show a belt pulley as well.

My thought is to attempt to size my battery pack to run my electrical system and "electrocharger" for 100 miles (running down to ~75% charge). That will give me a fair amount of spare capacity for longer drives and maximize battery life. Since the electrocharger can run at a constant rpm, the controls should be relatively easy: on or off. I'd probably look at a kit like this one for my e-motor kit. I would think that this would be powerful enough to do what I want.

Sure, it works. We know that. But is it optimal? Perhaps that 10% fe improvement could really be 15% if the engine was getting the power it needed for a hot spark, properly calibrated injector pulse, etc.

Of course a car should be able to run with a broken alt belt....but for how long? Any engineer working on a new design has the answer....just long enough to get it to a shop and get it fixed. When every device/system that manages, runs, and protects an engine expects to see 14v there is certainly no benefit to 12v, 11v....but there could very likely be a detriment.

Goodness! That means when my alternator is disconnected (running at 12v) my engine is making minus 100 horsepower!! :)

---

Here's one reason I would go with a hybrid type "boost pack" vs. an alternator delete (and I have a fair amount of experience running without an alternator).

In a word, "range anxiety". (Thank you GM)

Yes, you could always hook up your alternator again if you realize you're not going to make it to your destination before the 12v juice runs out.

HOWEVER, if you ever partially deplete your battery and then turn the alternator back on, you will take a massive fuel economy hit with the alternator running at high field current straining valiantly to bring the battery back up to ~14 volts again. Ask me how I know this.

Depending on how badly you misjudged your "range", your fuel economy could even be worse than if you'd just left the alternator connected from the beginning.

I dream of a lightweight, intelligent, portable lithium ion "boost pack" system that retains the ~14v level in the starting battery while the alternator is disconnected:

• the boost pack chemistry is better suited to deep discharges than lead acid (lower battery cost/cycle if done right)
• it has the advantage of being lighter than auxiliary lead acid batteries
• it's portable - could use it to power other 12v stuff sometimes
• it's portable - bring it inside to recharge instead of running a cord to your car, if not using PV solar panels on the car to recharge
• if/when you run out of range, you simply turn on the alternator to re-supply power; no massive "recharge" MPG hit since your battery was kept up by the boost pack

Just thinking out loud.

Of course, you could also carry a small, fully charged 12v "backup" battery to swap in place in this situation, and avoid the big "recharging" MPG hit.

(Or switch your OEM starting battery out of your auxiliary pack circuit, or... you get the idea.)

But the Li-ion pack idea seems cooler to me.

[QUOTE=MetroMPG;123666]Goodness! That means when my alternator is disconnected (running at 12v) my engine is making minus 100 horsepower!! :)

I'm confused....you're running at 4.5v?

WHoops! Not intentionally. :) NO, that was just me mis-reading your post. I thought I read "every .1v drop".

That leaves the Flea with ~25 hp @ 12v with a 10hp/1v drop from 14.5 v.

Which is of course, still not likely. The test vehicle related to that statement probably had a billion horsepower to start with.

PS - sorry for the OT burst!

Nope. It's do-able, if a bit complicated. Do it! Please start a build thread. :)

OK, good point, that info is useless without the original power of that engine. Assuming it was 300hp originally that works out to 3.33% power loss per volt.

It is pretty common in the racing world to run a 16v battery without an alt. Under the same sag as a normal battery that works out to ~14.66v, perfect. In that situation horsepower is all that matters, so clearly that extra voltage makes a difference.

What about design the battery so it can also be used in a hybrid bicycle? If the bicycle is then put on a stand, it should be possible to generate about 100-300Wh of free electricity every day. (And during the winter, even more savings by not having to run the heater as much!)
And in the car, design it to use regenerative braking. More free (recovered) energy.

If I'm going to pedal my arse off, it's gonna be where the pedals are moving me down the road without all those conversion inefficiencies.

I'm thinking more of a portable regenerative gym on a bike to use when the weather is too bad for cycling. A HSD bike will get you that with just a stand to hold it stable (or just a software setting for a "tadpole" trike) and an IMA bike will get you that with a stand that raises the rear wheel so it can move with the bike stationary. (Note that a bike stand ("trainer") that raises the rear wheel is expensive - $80 is the cheapest one I've seen so far. That's a good reason to go with HSD!)

Lotus is working on an add-on hybrid system that replaces the alternator with a starter/motor/alternator combo to add the stop/start feature to non hybrid cars.

Lights won't only put out less light at lower voltage, but will not last as long. I also wouldn't recommend it for some cars with already undersized wires for their lighting.

There is a Lithium-iron phosphate car battery made by Voltphreaks that weighs about 4 lbs. Also costs a grand or more. Odyssey also makes batteries in the 16-26lbs. range for a reasonable price.

Got my Cycle Ops bike trainer stand for under $50 on ebay.

That doesn't add up. Electricians have been using 130volt bulbs in hard to reach places for years precisely because they are underrated at 110 volts and last much longer.

Some gas discharge bulbs (including fluorescent and HID) will fail early if dimmed below specifications due to uneven cathode wear. Halogens also wear out early due to halogen corrosion.

But normal incandescent, LED, and most cold cathode bulbs will last longer at low powers.
Still expensive for what it does. Considering that 3 ton jackstands are available new for as little as $20, the bike stand should cost more like $10-$15.

SO you don't think that voltage sag occurs then? 'Cuz I hate to break it to you, but almost as soon you start running off your battery alone, you're not running on 12V anymore.

By the way - your 12V battery, when fully charged, contains something closer to 13V. It's 12V *nominal*. Test it some time.


Darin -

The conversion factor for your car's lost HP will be quite different, obviously, because the vehicle in question was probably running very high-tension ignition system, high power fuel systems, and making something close to 1000+ HP. At that point, you could imagine that for each 1VDC from 14.5VDC, they'd lose 10HP or so... for a 1% efficiency loss.

Applying that to your car, assuming you have the same draw as that engine has - You'd only be losing 2.5% of available HP, in your case, a figure not even noticeable by multi-dyno testing. Of course, the calculation for HP loss will not be linear, either.

Frank -

Oh, you mean this :

http://ecomodder.com/forum/showthrea...rger-1729.html

CarloSW2

Under voltage=lower bulb life and less light. I used to work for OSRAM Sylvania, but since I know you won't listen to me, here's the first link I found: The Truth About Daytime Running Lights | The Truth About Cars

I don't see how the cost, weight, and loss of storage of extra batteries or the possible reliability issues/extra vigilance necessary to eliminate the alternator is worth it. To each their own, but it seems like spending a dollar to save a dime to me.

What if the extra battery is easily removable and usable for other purposes? Like a hybrid bike, for example, or a portable power supply for electronics and power tools.

With a very aerodynamic car I've seen 20% improvement in steady highway cruising with an alt delete. The total system weight need only be 20lbs with lifepo4, 50-60lbs with PbA. I dropped 35lbs by swapping out my starting battery for a tiny AGM.

I spend about $3000/year for fuel. If I save 20% of that, that is $600. I could build a lifepo4 delete for less than that.

All solid state, no moving parts. No belts to break, bearings to go, and no need to deal with the high temperatures under the hood. I could see a reliability increase.....

PS - I believe you that the bulbs wouldn't last as long. This is not the first time I've heard this - low voltages due to corrosion build up are blamed for bulb failure in classic cars.

I can believe that without any problem. My church had an oddball light fixture in our sign which was set for 90V (if I'm remembering correctly). Put a 110 bulb in it and it wouldn't last a week. We finally swapped out the guts to use a 110 bulb.

Yeah... I've started running the numbers. I'm estimating I'll spend about $1300-1500 per year on gas. I'm figuring I'd have to spend a minimum of $750 to get a system in place. I'm estimating a three year payback... ouch!

You could build a system out of 4x 36v dewalt batteries ($400) + a 36v 100a motor controller for a scooter ($100) that has ~330watt-hours of juice. Enough for ~23 Amps at 14v for one hour. More than an hour in the car and you can switch the alt coil back on without any further MPG hit because your battery is still charged as normal. The system would only weigh a little over 10 lbs and could easily be used elsewhere for drills, e-bike, scooter, etc

I'd go for a little more power, personally, but if you're worried about payback time then you want to choose a pack size that will be depleted in a normal commute and no more. That would net the maximum return for the least initial expenditure. That 80% extra for 2x the range doesn't make sense if you'd only use it 5% of the time. Numbers are fun :p

LOL, I hate it when I'm wrong, <quietly slinks away> :)

I Wasn't making up the 130 volt stuff, and many headlights are halogen, which niahomike indicates is reduced life with under voltage too. So for improved life, corner lights like lowered voltage, LEDs like it, halogen headlights, not so much.

Back to the original post...
Even better - run the alternator as a brushless motor. This requires no modification to the car. You can get PMA generators on ebay, generally for windmills and such, that are nothing more than car alternators which have had the wound stator replaced with high-power magnets. I saw a thread on Rcgroups.com about doing exactly this, using an alternator made PMA as a high-power brushless motor with an off-the-shelf castle creations HV 110 ESC. How to Convert an Alternator to A Motor - Page 11 - RC Groups

That ESC costs $180 and can handle 50 volts and 110 amps. There is even a 140 amp version. That would be 7000 watts, or around 9 hp. It is sensorless, so you don't even need to add anything to the PMA.

I don't know to what extent it makes sense to supplement the engine with batteries though. At some point you're better off building an EV. I don't know where the line lies

I've been looking at alternator conversions... I have several old "blown" alternators laying around... they need voltage regulators and such, but anymore, it's cheaper to just get a lifetime one, and be done with it.