I want to completely remove my belt

[Daox]

Originally Posted by Baltothewolf

What is the best deep cycle battery to get anyway? Like for an insight.

You already got one in the back, its used for your hybrid system. Your dc-dc converter charges your 12V from the HV pack.


For non-hybrids, it all depends on how much time/range you want. I went through the calculations in my thread here:

http://ecomodder.com/forum/showthrea...ete-30363.html

[NoD~]

Originally Posted by Ryland

The main idea as I understand it of an under-drive pulley is when you are pretending that you own a race car and you have put so many after market parts on that it no longer idles at a reasonable speed and you drive with high revs you install an under drive pulley because the engine is always spinning faster, but it is true that the larger the pulley the less energy is wasted bending the belt and the looser you can have the belt as well because it's making more contact with the pulley.

Purely from a power/acceleration perspective: When it comes to low end boost, I have yet to find anything "bolt on" that can beat an under drive pulley, especially for the price. I've done it to several cars, but notably, all my Neons and the Scion xB (which, with it's auto trans, was excruciating to accelerate prior to the pulley). The gains are noticed from the bottom end all the way up, unlike any intake and exhaust work (minus boost! lol). I think a lot of it comes from the weight difference in rotation, though. Shedding several pounds off the crank, as well as a slightly tighter diameter brings what little weight there is closer to center seems to really where it shines. MPG wise, I've never done a good A-B-A comparison, because they aren't exactly easy to swap out.

Chiming in back on direct topic, I'd be curious how much distance people are getting on no-alternator setups. With alternator and small battery, I would find myself having issues keeping decent voltage when pulse and gliding engine off over 40+ miles. Note that it's with a very small battery, not some standard or larger deep cycle batteries. Since, I've added my "solar sunroof" that helps trickle charge and voltage hasn't been an issue since (haven't driven the distance at night, though, where the lights make the engine off portion nearly impossible).

[Daox]

If you're going to disable your alternator for any real length of time you NEED a deep cycle battery of appropriate capacity. IMO its not a viable mod without one.

[California98Civic]

Originally Posted by oldtamiyaphile

Didn't Darin test this? IRC he found a 5% gain by switching the alt off, but another 5% (10% total) with the belt removed in his Metro. I suspect a larger engine won't see as much benefit.

Yes, his results are something like 10%, but all he did was remove the alt belt: http://ecomodder.com/forum/showthrea...8.html#post958

I can't recall if he ever did a switch. His Metro has an old alternator design where it is always on. My Honda and most more recent cars, perhaps all, have a "smart" alternator, with an electric load detector that turns the alt on at different levels and shuts it off, essentially, sometimes. It optimizes charging and fuel economy. So, for me the benefit of the alt on/off switch has been smaller. But it is there.

I agree with Daox about NEEDING a deep cycle battery. Mine is 40 amp hours capacity (Odyssey) with a 25 amp onboadd charger, and I needed the metal jacket battery variety because all my grill blocking elevates engine bay temps. I have been running it for years now, plugging in at night at home and sometimes at work during the day. No problems once I had the sgstem configured properly. Whenever I need range, I flip the alt on to run normally, or occasionally if I feel like hypermiling a partially charged battery.

James

[oldtamiyaphile]

Originally Posted by California98Civic

My Honda and most more recent cars, perhaps all, have a "smart" alternator, with an electric load detector that turns the alt on at different levels and shuts it off, essentially, sometimes. It optimizes charging and fuel economy. So, for me the benefit of the alt on/off switch has been smaller. But it is there.

A 'smart' alternator, by my definition is one that ramps up during overrun, ramps up to max under braking and puts out no current at all under normal operation (unless of course a load is applied). My Fiat has such a beast and by charging the battery when parked, I essentially have an alternator kill switch that still does regen. Sadly, while it's a common feature nowadays, it's still not universal (my newer Renault doesn't have one).

[California98Civic]

Originally Posted by oldtamiyaphile

A 'smart' alternator, by my definition is one that ramps up during overrun, ramps up to max under braking and puts out no current at all under normal operation (unless of course a load is applied). My Fiat has such a beast and by charging the battery when parked, I essentially have an alternator kill switch that still does regen. Sadly, while it's a common feature nowadays, it's still not universal (my newer Renault doesn't have one).

Yeah. That would be the smartest, but of course that could be insuffient charging time. My alternator works as you describe, with one difference. When the car crosses 40mph, the alt begins to run all the time. Inly my alternator switch prevents that. And sometimes, after I key on and in some ither situations it runs at fjll on acceleration. The switch prevents that.

[oldtamiyaphile]

Originally Posted by California98Civic

Yeah. That would be the smartest, but of course that could be insuffient charging time. My alternator works as you describe, with one difference. When the car crosses 40mph, the alt begins to run all the time. Inly my alternator switch prevents that. And sometimes, after I key on and in some ither situations it runs at fjll on acceleration. The switch prevents that.

So your car sits at 12.8v as long as speed is below 40mph? My Fiat will do at least 140miles using just overrun alternator operation with daylights and A/C on, and that includes (automatic) idle stop restarts.

[California98Civic]

Originally Posted by oldtamiyaphile

So your car sits at 12.8v as long as speed is below 40mph? ...

Yes. Unless the voltage or load crosses other limits/thresholds. And climbing hills at low speeds the voltage will sit even lower. It also will maintain a low charge in some conditions. For example, just before climbing a slow hill from a stop, my voltage meter shows say 12.34. I key on, begin the climb, flip the alternator switch on, and the charge climbs and stays only at 12.5 volts during the whole climb.

We're probably a little off topic for the OP though...

I think one message of the thread is probably that removing the belt is an option but not necessary, though it would be simple. You could do an alt on/off switch instead and have less range anxiety. Whether you remove the belt or install a switch, get a deep cycle battery and a plug-in, on-board charger with a capacity 50% or more of the amp hour rating of the battery.

[oldtamiyaphile]

Originally Posted by California98Civic

Yes. Unless the voltage or load crosses other limits/thresholds. And climbing hills at low speeds the voltage will sit even lower. It also will maintain a low charge in some conditions. For example, just before climbing a slow hill from a stop, my voltage meter shows say 12.34. I key on, begin the climb, flip the alternator switch on, and the charge climbs and stays only at 12.5 volts during the whole climb.

I'm really impressed Honda were doing it all those years ago. Do you know how the alt is controlled? I wonder if it could be a simple retrofit for 'dumb' units. Based on my experience with 'smart' alts, there's a good 5% gain to be had with no drawbacks.

[Daox]

I dunno about the 98 Civics, but my 02 I had has a current sensor in the fuse panel to keep track of current in/out of the battery. So, its not a simple swap.