12v Charge Controller
 

My wife recently forced me to acquire a Honda EU2200i (2200W inverter generator, I've always wanted one...) One of the things this generator offers is an 8.3A 12V DC connector to "charge 12V batteries". Unfortunately, it's an unregulated output. I need some suggestions on what type of charge regulator to use? Because cooking batteries is an expensive proposition.

Potential battery types I'm looking to charge are Deep Cycle lead acid, or Lithium. (yes, I know they're distinctly different charge voltage cutoffs and float voltages). Suggestions please...

Just convert a server power supply into a charger, now you'll be able to use a substantial percentage of the generator capacity.

I suppose, aside from the step-up and step down power losses...

I was really only searching for some form of voltage regulation for the unregulated DC output on the generator. Alternators in cars come with voltage regulators to avoid cooking batteries. There's probably still a Bosch 90A brush and voltage regulator (combo unit) in my collection of VW spare parts.

I guess I'll just dig in the garage and see if I have any of the scrap Vector 12V smart battery chargers. We had a fleet of these "smart chargers" at my office, to recharge 12V deep cycle batteries every night. I still have one 20A Smart Charger that works and that would be plenty of charge to whatever battery system I end up with...

What about an RC/hobby charger with DC input? I have one similar to this that I used when refurbishing my Prius' battery and now it gets used as a fancy charger for lead acid on occasion.

I've got one of those RC chargers (older model) that still works, but my guess is, the DC input to the charger would need to be a volt or two higher than the charge voltage needed for a 12v lead acid.
The 12V SLA that I use for RC is dying, so much that I was unable to recharge some tabbed AA cells with last week. I think it was down around 10v.. :( (I was replacing the batteries in my razor, and wanted to test them).

If that unregulated 100w 12v port on the gen doesn't get above 13.6 volts, it should be able to charge a 12v lead acid car battery a bit, without over-charging it.
If it was me, I would use that 12v tap to power USB chargers or to charge up some some portable LED /w battery lighting for use outdoors. Might be useful when you need to add fuel to the gen.
It might be a gen you would take "camping", so aux 12v LED lights and USB ports might come in handy.

They actually don't need the input voltage to be higher than the output. I've always run mine off a 12v xbox 360 power supply and used it to charge batteries higher in voltage. The specs for the charger I linked to says the input voltage range is 10-28v, so that 10v lower limit is probably what you ran into.

I think you might be correct!
 

I have never charged any RC nicad or nimh that had a lot of cells, nothing over 12v. Looking at the charger now, I see it can charge up to 25 cells! WOW! It should be pretty good on a 100w 12vdc source.!.
I'm keeping this when I get rid of all my RC stuff.. (but the sail boat).. :o

That's basically what I was thinking must exist out there somewhere in the world... That's actually an intriguing product. I like the wide input range it handles. I can probably find a PC PSU from an old tower PC to drive it as a benchtop charger.

Check out the specs on the TS-45
 

Morningstar - Tristar 45A Solar Charge Controller for 12V/24V/48V Batteries, Lowest Fail Rate in The Industry, Built-in Diagnostics, (TS-45)
Brand: Morningstar Corporation

The last one I ordered was $178 and I hated spending that much for a spare!