after installing my new E-waterpump I thought it time to bump up the juicer. I have... E-fan (Volvo) E-waterpump A/C MSD Atomic EFI MSD timing controller E-fuel pump fog lights running lights wipers sequential tail lights (6 1157 bulbs) with all this I had the alt bumped up from 103 amps to 200 amps ($169) before on startup I would have 14.3V. as it warmed up it would drop to 13.1V. if I turned the A/C on it dropped to 12.5V. if I set at a stoplight at idle more than a few sec. it would drop lower (11.9V). now...startup is 14.5V... with all this on: E-fan (Volvo) E-waterpump A/C MSD Atomic EFI MSD timing controller E-fuel pump fog lights running lights wipers sequential tail lights (6 1157 bulbs) it stays @14.3-14.5Vs anything above 800RPMs...anything below 800RPMs it's 12.3-12.5Vs... also with the install of the E-waterpump and a new alt bracket I could do away with the long serpentine belt, idlers and belt tensioner...
if I can keep it at 12.3-12.5V at idle that would be OK. I'm looking for a...clutch pulley...if it's a smaller OD that would be a plus. have entertained the idea of putting a one way bearing in a stock or smaller pulley...
I would run the setup for a while. Don't think you will/rarely operate all those electric devices at once. Don't think you will op below 800 rpm a lot. I run 130amp w/ AC, elec fan and stero amp at idle about 13.8 according to Auto Meter gauge. I have car setup to run 800 rpm at idle.
I have been in situation , hot summer nite, stop light, AC , stero amp, never had an issue for a few minutes at the light. If I run into a problem for long wait on something like train crossing, can turn off head-lights "use park lights" and put car in neutral.
"Resting fully charged 12 volt batteries are around 12.8-12.9 volts, and flat dead ones are at 12.0 volts, so 12.4 volts on a resting battery means it's about 50% charged."
I believe 12.5 is normal rest voltage and would/could be far greater than 50%! IIRC I have checked voltage on my 7 yr old wet cell and at rest it's around 12v or so, never had an issue w/ it powering all accessories or cranking engine. I keep batt. on maintainer during long inactive periods; not going to push my luck, getting new one next season.
You cannot use static voltage to determine how much charge there is in a battery. A rough guess at best, BUT a battery with 12.8 12.9v is overcharged. Seen batteries with 12.6v not begin to crank the engine, yet another with just barely 12v cranks fine.
got this from a Google search... "Resting fully charged 12 volt batteries are around 12.8-12.9 volts, and flat dead ones are at 12.0 volts, so 12.4 volts on a resting battery means it's about 50% charged."
