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

[brucepick]

Woo-hooo!!
Lithium pack is installed and functioning.
Alternator is disabled.
Current tank is averaging very close to 52 mpg. It's been at 52 before, but not lately.

Still need to install some fuses, and switches for more convenient operation. Those are due in this week.

[Daox]

Good to hear. Looking forward to hearing results. It should be interesting to see what the reduction in load does for being able to keep you in lean burn longer/easier.

[brucepick]

Originally Posted by Daox

Good to hear. Looking forward to hearing results. It should be interesting to see what the reduction in load does for being able to keep you in lean burn longer/easier.

It definitely does help. The limited access road I take to work has significant hills. Without the EPES (Externally Powered Electrical System) some of those would always get the car out of lean burn due to the increase in gas pedal depth needed to make the grade. Now with the very slight increase in available engine power at any given throttle setting I can nearly always make it up the hill without losing lean burn.

[California98Civic]

Originally Posted by brucepick

Woo-hooo!!
Lithium pack is installed and functioning.
Alternator is disabled.
Current tank is averaging very close to 52 mpg. It's been at 52 before, but not lately.

Still need to install some fuses, and switches for more convenient operation. Those are due in this week.

Awesome, Bruce! For comparison, I'll report what I have noticed recently with my 6 month old version of this "externally powered electrical system" mod. Since going to the full use of the alt delete switch and DFCO for battery charging my battery's ability to hold its full, overnight, grid charge seems to be rapidly degrading. I used to be able to drive my commute 22 miles with the battery only beginning to dip to 12.0 volts, but now 12 miles seems to do it. With DFCO and short alt runs I can keep enough juice to operate. But the battery has been in place just 6 months, and it appears to be growing weaker under all the deep discharge cycles already. Sad.

And I am seeing an impact on trip MPG figures inverse to what I had seen before. Night driving can no longer go long at all without the alternator engaged to support the lighting. Running the alt all the time seems to reduce MPG at least 10%, maybe 15%, on those trips. It's the difference between mid-low 60s and mid-high 50s. Very noticeable.

I imagine a set of solar panels (my next big electrical item) will help by preventing such deep discharging on the battery. But perhaps I need a different battery arrangement, something more like yours.

james

[Daox]

Are you using a deep cycle battery, or starting battery?

Also, when its colder, a battery's voltage will sag more under load. As it gets warmer out you should see it recover at least some.

[California98Civic]

Originally Posted by Daox

Are you using a deep cycle battery, or starting battery?

Also, when its colder, a battery's voltage will sag more under load. As it gets warmer out you should see it recover at least some.

It is deep cycle, but I opted for the unusual step of a much smaller battery, an Odyssey PC625, which was actually designed for a motorcycle. I greatly reduced electrical loads (lights mostly). I have wondered if the 40amp current from the alt might be overcharging and damaging the battery: how powerful is the typical motorcycle alternator?

[brucepick]

Cali98Civic,

I wrote and spoke several times with the people at Odyssey (Kathy).

I learned that the Odyssey batteries have somewhat unique charging requirements. Granted "unique" isn't supposed to be a relative term but you can't charge them the same as regular lead acid batteries. I do believe you should be using one of the Odyssey brand chargers, and you also need to ensure it's one they specifically recommend for your particular battery model.

Their chargers - I'm pretty sure - have a desulfation mode to help correct "capacity degradation". Maybe not the least expensive ones. I think you'll need to research it in some detail.
Odyssey charger descriptions
Odyssey charger manuals

My hope is that my setup will avoid battery degradation. I'm using a LiFePO4 pack, as you're likely aware if you've been following this thread. The pack has a "Protection Circuit Module" built in, which is a kind of passive Battery Management System, it balances the cells following charging. The charger is built for LiFePO4 cells. I disconnect the car from the Li pack before charging; at that time I keep it connected to the regular lead starting battery to maintain the car's computer and radio settings etc.

The lead acid battery only starts the car currently; it seems to last a week just fine. I think I'll charge it from AC on weekends.

I'd like to replace the lead acid battery with a deep cycle lead acid of same size. I could use that to power the headlights to give the Li pack a break; it should power a longer drive time that way. However with the daylight savings changeover this weekend, I'll not be driving with headlights daily so I don't think the charge drain from headlights will be a major issue till November. When I occasionally do a long road trip at night, I'll knuckle under and power the car off the alt plus starting battery.

[California98Civic]

Originally Posted by brucepick

I do believe you should be using one of the Odyssey brand chargers, and you also need to ensure it's one they specifically recommend for your particular battery model.

I do have one of their chargers, and it's the one for my model. Excellent item. I actually wonder about the alternator charging because of the fact that the charger seems to offer a particular charging regimen that the alternator, of course, will not do. I wonder if the alt can damage the battery.

Originally Posted by brucepick

Their chargers - I'm pretty sure - have a desulfation mode to help correct "capacity degradation". Maybe not the least expensive ones. I think you'll need to research it in some detail.

All the chargers, cheaper or pricey, list the same characteristics (at least online), except amperage. Mine does the whole three stage thing they advert. I'm suspicious of the fit between the way the alt charges and the specs of the battery.

Originally Posted by brucepick

I'd like to replace the lead acid battery with a deep cycle lead acid of same size. I could use that to power the headlights to give the Li pack a break; it should power a longer drive time that way. However with the daylight savings changeover this weekend, I'll not be driving with headlights daily so I don't think the charge drain from headlights will be a major issue till November. When I occasionally do a long road trip at night, I'll knuckle under and power the car off the alt plus starting battery.

I think this is a great sounding plan. I guess I'm sharing my current experience because it might speak to your selection of a deep cycle battery. Perhaps our alternators do not charge these batteries well and shorten their lives? [EDIT: it is worth adding that the Odyssey charger for my battery is rated at 6amps and my alternator puts out 40! I think I screwed up, no?]

[oil pan 4]

Originally Posted by California98Civic

how powerful is the typical motorcycle alternator?

Permaniant magnet charging systems like that typically put out around 20 amps max. + or - 5 amps to that 20 and it covers pertty much everything.

Your discharge rate life expectancy does have some relationship to charge rate life expectancy.

The optimia batteries I use at work have an absolute max charge rate of 60 amps. Max recomended charge rate is 40amps and most of my equipment charges its optima battery at a rate of between 10 and 20 amps and they last a long time.
They also weigh 44lb.
Back when I use to work with smaller batteries about half the size of the optima on lawn and garden, motorcycle and ATVs I figured you wanted to charge them no faster than 1 amp per pound of battery.

Originally Posted by California98Civic

it is worth adding that the Odyssey charger for my battery is rated at 6amps and my alternator puts out 40! I think I screwed up, no?]

Did you ever put an ampmeter in line with your battery to see how much alternator power is soaking up?

When ever I have used deep cycle batteries, even hundreds of pounds of them all in one stack I have only used up to 20 amps to charge them.
These batteries are 6 volt and slightly larger than the batteries in my truck, each cell is more than double the size of the cells my starting battery.

[brucepick]

My discussions with Odyssey told me that the ideal charging voltage was somewhere above 14V. I didn't commit all the details to memory but I think 14.1V was the minimum for "successful" charging from an alternator, and 14.3V or 14.5V is better. I think your ~14V charge rate, and the weatherproof plug-in charger you mentioned earlier (not by Odyssey??) are likely the what are primarily keeping the battery from optimum performance.

Now, if your drive discharges the battery substantially and you then activate the alternator to charge it, you may well be giving it very high amperage, especially if you don't have many accessories running. That may not be a bad thing. Check the Odyssey specs for charge rate limits. I think that with a limit of 14V you're not gong to overcharge it, even if the alt has a 100A capacity. However as I noted above, they really like more like 14.3-14.5V for charging, not the lower 14V rate.

The alt's Amps rating is a capacity, not what it will constantly deliver. The voltage regulator keeps it very close to 14.0V (except when the Honda ELD circuit cuts out the alt temporarily for fuel savings) but the Amps will vary to meet whatever the car needs at the time. If you're running headlights + cabin fan + radiator fan the alt will deliver more amps than without those items on, up to it's max capacity of 70A. If you're trying to draw more than what the alt can deliver, the voltage will sag somewhat, depending on how much more amperage you're trying to draw beyond the alt's capacity.

In the scenario above, a discharged battery that's now charging will present a "load" to the alternator and it will provide amps to the best of its ability, up to the 70A capacity of the alternator, while maintaining its regulated 14V. I think it's quite possible the mostly discharged battery will soak up as many amps as the alternator can deliver.