brianjw wrote:
I’m going to run a 400 amp hour lithium battery setup. I want to be able to run the roof top AC off of the Victron inverter while driving (or just quickly recharge the batteries while driving). The plan is to run a 60 amp sterling B2B charger off of each alternator, for a combined 120 amps to the lithium battery bank. I don’t want to overwork/overheat a smaller single alternator asking too much from it, and this seems like the safest way to do it. A little overkill, sure. No, I don’t want to have to rely on the generator while I’m driving. In fact if the solar and alternator perform well enough the generator will come out.
Just a question: Wouldn't it be cheaper and easier to just pick up a spare of the alternator currently installed on your rig and IF your original alternator bites the dust, you can just swap it out? A 210 Amp alternator is pretty beefy. And once you have original one out, you can probably rebuild it (oftentimes it's the brushes that wear out) and it'll be ready to serve as a spare.
First of all, as many can attest, IF you have a spare part...you rarely need it...so you're almost guaranteeing trouble-free operation for as long as you own the vehicle! :)
Second, you're putting off the work until later...if ever. Ok...that might just be me, but I'm known for "never do today what you can do tomorrow!" LOL
Lastly, I'd NEVER get rid of a functioning generator in an RV. IF you ever go to sell it, I think a lot of people will see that as a red flag. And if you're going to keep it, it needs to be run periodically anyway, and we do that while travelling down the road, keeping the A/C's running. And ten years ago when a freak October snowstorm came through knocking out power for almost a week, there's something comforting about having a generator with a 75 gallon gas tank (in our case). :)
Just thinking here...as to the emergency vehicles with the dual alternators, I believe that's because they often spend long hours at idle with their lights on and a single alternator with the engine at idle, might not provide enough juice to keep the batteries charged. Plus, as you said, there is some redundancy, which could be critical in some situations. I also wonder if they don't incorporate a high-speed idle switch as well to get the engine spinning a bit quicker? Of course, newer vehicles use LEDs for lighting, which, theoretically, should reduce the need for as much charging juice during those situations.
Trust me, I appreciate the ideas to mod your vehicle, I like to mod my vehicles as well, though with increasing age, I've scaled back a bit. But on a brand-new vehicle, I'd be really hesitant to do anything to the chassis.
Good Luck, I hope you're able to find the information you need. Please come back and post whatever you find out so perhaps someone else reading these forums in the future can benefit from you experience! :)
~Rick
