Wow congrats! Early pioneers get to catch all the arrows
Just background thoughts, detail questions for you to answer & terminology nitpicks here.
100% agree try to use as is, keep warranty valid of course.
Yes going between AC and DC is "inefficient"
Sticking to the native DC only, and going from high voltage down to lower - buck conversion - is much better
than boosting from low to high.
From grid-style AC power to DC is what is usually called **charging** since battery is usually involved, technically you are rectifying if not.
Converting can in the USA RV world be used for the charging process, but that is confusing usage, best to just use that term conversion, for DC-DC whether buck or boost.
From DC to AC is inverting, using an inverter, usually from stored power to feeding grid-style loads.
Proper high amps gear in any of these categories is usually very expensive if safe and reliable, not an arena for cheap chinese unless you **really** know what you're doing
You need to keep things as simple as possible, so tossing certain (high) voltage batteries into the mix just because you have them already does not make much sense, should not drive your choice of system voltage.
Possibly, the 72V packs could be broken down to serve the usual 12V or 24V or even 48V standards, whichever you choose for basic design reasons
but more likely it would be best to just sell them as is. LiPo is very fire-risky, best to stick with LFP or maybe LTO for House storage needs.
What voltage is the high-power output of the onboard gennie?
I would assume the same as the propulsion pack?
Charging eBikes requires a much higher source voltage than the nominal pack rating, which is usually the 50% SoC halfway point down the discharge curve.
If those 72V packs are 20S (please confirm) then you need 83V input precisely to charge them.
And as I said, buck conversion is much better than boosting.
Also forget charging from storage, i.e. a battery bank, super inefficient, you want the gennie running, charging your House bank, the vehicle pack and your (relatively small) eBike packs at the same time
with buck converters tapping into that high power high voltage DC as their input.
Keep this "genset running for charging" scenario separate, really should be its own ("Topic A") thread once you get into the weeds and later to be broken down at each of the three voltages involved.
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Another, completely separate "Topic B" is powering your very high consumption loads
space heater, HWS water heating and aircon
do not call those "accessory" here, confusing see below
Set aside for now, but just realize you would need a very high kWh battery bank costing thousands to power any of those for more than a few minutes a day from storage without the genset running in support at least some of the time.
I'll use a sine wave converter (found one that converts 60v-90v DC to 110v AC) to convert the DC battery charge to AC for all of these accessories.
As discussed, that would be an inverter, and wow, very rare for there to be a DC storage bank at that high a voltage. DC versions of some of those device loads would be more efficient, or even avoiding using electricity.
As I said, set that aside for now.
Mire questions:
What is the power output limit of the truck's built in inverter(s)? Is it designed to run off the (very high voltage) propulsion bank while the motor is turned off?
Does the gennie automagically kick in as those loads draw down SoC% to a certain low point, or does it just cut off feeding the inverter?
Or does the inverter only run off the little accessory 12V battery?
> Is there anyway I can safely go directly off the alternator?
I doubt **if there is** a normal alternator as such, there is no FF motor in there to tap into mechanical energy to produce electricity.
That is what the genset is for, doing that on its own, while the propulsion systems are doing the Opposite.
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Topic C will be your "normal" power House loads that **can** easily run off stored energy for many hours or even days.
That House bank should ideally be the usual 12V, but 24V or even 48V
higher being better if the very thirsty "B loads" are also fed from that same bank for brief periids in between the genset running them plus recharging at the same time.
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As we move forward in discussing these issues in more granular broken down topics, we will quickly get beyond my personal knowledge base and also at some point the pool of members' knowledge here
I would suggest creating separate specific individual threads over at Endless-Sphere.com and the DIY EV forums, maybe keeping those here as a central repository for settled issues and record of specific Ford-EV factoids and recommended devices.
So, def get a good DMM and ammeter for checking on volts & amps
as well as coulomb counting wattmeters for measuring charging and consumption Ah and Wh over time.
And try to get answers to all outstanding questions as we go, to help guide the basic "top level design" aspects if the discussion.
As soon as you see assertions or phrasings you do not fully grok, please ask specific clarifying questions, do not move forward with gaps in your understanding.
Same with statements you see that you would like to challenge, this will be like herding a bunch of cats (apparently a clowder of cats)
and there are often many different ways to skin any given cat
