I didn't want to highjack the thread about adding a 2nd alternator so here's my sidebar off that thread ...

I got a 180 HP alternator for my 2003 about 2 or 3 years ago from DC. It's a modified 6.4 offering because they dickered me around back then and offered me this as a compromise ... https://www.dcpowerinc.com/fit/Ford~...91-180-hp.html

Anyway, my question is, now that you got me thinking about it, in the winter my highway mileage takes a huge dive, and most of my trips are short explosive hard drives to the fire dept when the tones go off .. about 1.5 miles there, 1.5 miles back. I guess I'm not getting much of a charge then from a 180 alt? Should I idle it for a bit after a call? Plug in my battery tender more often? Don't usually want to take the long way home.

My gauges say I'm starting around 11.8 - 12.1 (depends on temp) and I'm up to 14.3 - 14.6 once GP's go off. Dips to low 10.0's during cranking, and FICM is never below 48.0 ... usually 48.5- 49.0.

Any one got any comments for those of us who first respond in the 6.0 in cold weather as relates to the charging system? How quick does the vehicle charging system get the batteries back to ready for another cold start? {I do leave her plugged in 100% when she is in my driveway}

Thanks.

 

You know the best way to see how long it would take to recharge would
be to watch the voltage on each battery and then take a reading with
a hydrometer. That is the long pain in the *** method.

If you have access to a battery load tester you could run a short set of
tests to see what it takes to reach a good recharge level.

The variables being alternator,cabling condition,outside temp
and size of the alternator pulley. By running with the smaller
pulley you will increase the RPM that the alternator runs at.
By spining faster you reach the rated output sooner with
your alternator.

When playing with pulley size you need to make sure that
you don't exceed the safe maximum RPM for that device.
I don't think this would ever be a problem for un in this application.
But you never know.


Sean

 

Dam, have to agree with Sean again today on the hydrometer test. Only way to really know what's going on with the batterys. Amp meter shows what is going to them but is no indication of their state of health.

 

My local commute is a few miles at 20-25 MPH through town.
When it's cold/cool here in FL. With my stock alternator.

I use tow/haul and with my RPMs at 1500+ I get 14v on my analog gauge. My biggest concern is engine coolant/oil temps not getting up high enough. Luckily, I run errands twice a week and with the FIA Winter Front I can get my fluid temps between 190 and 200 w/o much effort.
I hope to install my new DC alt + wire upgrade this weekend and will be very interested to see how it works.

 

Regular use of your battery tender is not a bad idea though. I have randomly picked the once a month timeline for mine, usually takes the BatteryTender about 24 hours to show a solid green light for me. Only time will tell if it helps the life of the electronics, I haven't had the truck even two years yet.

 

I don't really have load testers and hydrometers to play with.

So when my volts read 14.x on my Edge Insight after the GP's have done their thing, that is when the batteries are being recharged, correct?

And a 200+ amp alternator will do that quicker than a 180 amp alternator I assume?

 

With a 230+ alternator the batteries will be seeing 13.5+ volts immediately from start, rather than waiting until the GP cycle off.

Translates into healthier batteries and a happier FICM. And that was my main point with short trips, a happier FICM. If someone is doing short trips, multiple errands and constantly restarting the engine, imagine what the FICM is feeling with constant low voltage from the glow plugs.

 

I leave my truck plugged in to my block on nights I'm running. And switch to my minder when It's just sitting in the driveway

 

Yes & yes the 200 will charge the load slightly faster. You could install the high idle mod, this would raise the charging amperage. At idle i would shut off your headlights.

 

I have a battery tender hardwired into my truck on the drivers side. The passengers side is the block heater.

 

I've been wanting to do that for awhile. But right now I just have the lose plugs. Looks good

 

Gotcha. I guess the best I can do is battery tender 100% of the time. I'm not going to buy another alternator ... almost $600 to get to the 230+ amps.

 

Nice. I wanted to do that too. My block heater is hard wired to a marinco like yours. What I really wanted to do is get a stainless steel inlet plug but the stainless only start at the 20 amp ones. The 15amp plugs are all plastic. I'd have to get an adapter or start chopping cords.

 

Also Josh, can you explain how that happens please. I thought somehow the batteries were receiving nothing from the alternator while the GP's were on. Is it the size of the alternator that somehow is overcoming that?

Thanks for helping me get a better handle on the charging system.

 

Mythbusted a while ago. The alternator is commanded on immediately, however, pretty much nothing below about 190 amps cannot handle the load and will still not see much over 12 volts with GP cycling.

190-230 will see around 13 volts at the battery, and over 240 amps will see 13+ volts at the battery.

All that is ball park, that isn't to say one manufacturer has a 190 that can output 13+ at the battery and another's 220 will barely see 13.

I have a 240 amp Mechman, I see 13+ volts on immediate start. I also notice the GP cycle off sooner than they did with a stock alternator.

It's too bad Ford went with the 110 amp 6G. Kills a lot of batteries and FICMs, especially those that do short trips and a lot of cold starts.

Josh