Well shit folks.
Should say at the top, I've got to check for parasitic draw, I have messed around with the electronics quite a bit in all reality. Stereo installation, upgraded coils, pulling from relays for the e-fan, power door locks, but it looks like our alternator is on the way out or is just not capable of keeping up with the draw, That alongside a pretty beat up battery means we've got a race against time until we can't reliably start the truck.
The truck's been starting and driving reliably for the last few months, short of me leaving lights or the stereo running while I mess around with things. I just charged the battery at 30 Amps for about 2.5 hours, got a bit of a low boil, and was able to bring the resting charge back up to 12.6.
At idle, with every single system on, stereo at max, interior light, dash lights at maximum, Max AC, headlights, and radio max volume, and the E-Fan set to run constantly, the alternator is just not able to provide a charge to the battery, which in a weakened state is struggling to keep up with output. Either the alternator is on the way out, and not providing enough charge, or 95 Amps is not enough in the first place. Since it's been cool and I mostly drive during the day this has been fine, but as the summer comes on and big plans are ahead I need to be able to rely on the vehicle. If I take a drive during a really hot night and Back in Black comes on the stereo I'm TOAST.
Short of there being a catastrophic power draw somewhere, which seems unlikely since the truck's voltage doesn't seem to drop when sitting and starts every time so a new, or upgraded alternator is necessary. Even with an upgraded alternator, we'll need a new battery no matter what, that's just a matter of time, but I could probably still get some decent use out of the standard lead acid Duracell unit that's in the car, especially if I do charge it from time to time.
So let me hear about the options, currently the truck is equipped with what may actually be an OEM Motorcraft 95 Amp alternator.
Here's what I've been considering:
Alternator:
My first instinct is to purchase this
BBB Remanufactured unit from Rock Auto, it's basically the best deal I can find on a new 130 amp alternator. It's 100 bucks, add 50 for shipping, taxes, and duties, and it's still the cheapest at 153. There's options for 115 Amp units, but with future additions to the truck it'll be important to have some breathing room.
I could also pull an alternator form the nearest junkyard would be 80-90 dollars, it's pretty easy to identify the 115-130 amp units from their design and size, but I'll be honest I've never had any luck with used alternators, still just by going to look I could maybe find an upgraded unit, or at least one of the 130-135 amp units for a bit less money.
The evil little monkey in my brain says to buy this 320 AMP Mechman alternator that someone is selling used in an Ontario group, they want 700$ for it though, and its overkill, AND it'll probably increase drag on the motor impacting fuel economy, but frankly if I do end up successfully adding an electric AC compressor, and electric power steering, among other goodies it might actually come in handy. I could maybe talk the guy down to 600$ CAD, still a big ask.
Battery:
Option 1, I could maybe get away by attempting to recondition this one, I've never really done it before, but who knows maybe I can get some more life out of it yet. Still, I would like to have the assurance of more capacity and overall battery health.
Option 2, buy whatever cheap new battery is around. This is gonna cost 175$ on the light end, up to 250-300 on the heavy. When it comes to lead acid, I've rarely if ever noticed a difference between manufacturers. That being said, getting a solid deep cycle/AGM unit with a higher capacity could be a good idea.
Option 3, I do what the evil little monkey says and I spend 640$ CAD one of these:
https://dakotalithium.com/product/dakota-lithium-12v-60ah-dual-purpose-car-starter-deep-cycle-lifepo4-battery-1000cca/
These are slick units, and 641$ Canadian for one is a good deal. Still, it's a 600$ car battery. However, it would shed 20lbs off the truck which is always a plus, have ultra consistent power, 1000 CCA, and basically triple usable power compared to a normal lead acid unit thanks to a better depth of discharge, and a 60AH Capacity. They also say they last up to 11 years. This is one of those "End Game" parts for the build that I would like to buy no matter what, but it'll be underutilized right now. Still, I'm genuinely considering it.
Other considerations:
I want to convert all of the trucks lighting to LED to save energy overall, even though it'll be a negligible win. That means the dash lights, headlights, brake lights, and maybe even the glove box light. In this specific situation, it would actually be enough to offset how weak the alternator is, but only for a time.
At minimum I'm spending 250-400$ CAD, not including the proper battery charger I just bought. At the maximum, I'm spending 1241$ to pick up some pretty heavy duty parts to slap on a truck that originally cost me 2600$.
Let me know what you think folks, I'm probably just going to go with the reasonable options simply due to cost but that Dakota lithium unit is a genuine possible buy.