A $25,000* programmed controller interfacing with a 32 port $5,000 A to D interface and a few grand for FETs and SCRs would make it "easier".
The computer is reasonable. Three weeks of programmer's time, then two weeks of de-bugging, isn't cheap.
BULK CHARGING
We have a say 400 amp hour, 200 usable at 50% SOC
Down 200 amp hours, huh? Let's let the dominant Megawatt the one with the 12 hour time do ALL the work. No we are not using generator power for this one.
Dial in 14.8 voltage regulated on the pot. Five hours theoretical at 40 amperes charge rate is a pipe dream. Let's do a mental calisthenics and rudely GUESS (8) eight hours of bulk charge.
After all, this is the FIRST TIME the Borg will be used on this a flooded lead acid 400 amp hour battery bank.
Twist the timer to 8 hours.
Bored?
Come back in say 6 hours and see how the cells are doing.
6 hours and only four are bubbling? We weren't far off in our timer guess.
Return to find the timer shut of. AHHHH SUGAR! bigdeal. Twist the timer a tad then look at the cells. Oooooo they're all bubbling. The 8 hour guess was right on target. Not on target? Goose the timer another hour or so. Add that to the 8 hours.
Batteries are not feminine. They do not change their mind. If it took 9 hours this time it will take 9 hours the next time. 74% state of charge? Maybe 3 hours? This isn't a nuclear "psychics" crystal ball subject - an exact number or the plutonium will get angry.
Amplitude configured with time voltage/time is what determines when and how vigorously a flooded battery will start gassing. Higher than 14.8 volts gassing rapidly becomes overly sensitive to time spent at that voltage. Still worried. Fine. Set the voltage back to 14.7 or 14.5. Whatever you wish.
WITH A GENERATOR
Mama and Papa bear both go to work if the battery bank size warrants it. Dial both chargers up to 14.7 The one charger has a timer the second one doesn't. So a person can't do this and go over to friend's and watch a football game, drinking martinis a few hundred campsites distant.
Again, learn from the first episode how long it takes to get the cells bubbling.
Having an on-board ammeter makes this child's play. At 14.8 volts and a slump down to "X" amperes means the slightly bubbling batteries are charged.
This recipe may not be suitable for individuals who self induce short-term memory loss.
CRUDE means EFFECTIVE, and it means VERSATILE. When I go camping with $400 worth of batteries, I do not want to receive $300 worth of battery performance because a smart charger is insane and cannot tell a properly charged battery from ----.
If I EVER get Soooooooo lazy camping, that this CHARGER (not converter) overtaxes my energy or mental facilities, it it time to sell the rig, and go somewhere where room service is but just a "Dial 0" away.
But then I do not haul an $80,000 rig 300 miles, park, slam all the shutters closed, raise the satellite dish and tune in a television reality show depicting a crackling campfire while I watch DVD homicide dramas on another monitor, while the DW orders up elivered ribs and cracks a bottle of sparkling burgundy.
