Car Battery Recharging with ICs

I'm working on a car battery recharging project. So far, I've already worked with the Unitrode-Texas Instruments UC3906 recharger to refill small lead-acid batteries (1.2 Amp-Hours and smaller). I want to expand my reach to automotive batteries.

Basically, to provide some background, the UC chip is a temperature-compensated recharger that goes handles all 3 stages of charging (from Bulk charge to Trickle) semi-autonomously.

I'm at loss here because it never occurred to me use this on car batteries so I'm unfamiliar with its capabilities in that area. Charging quickly isn't a major concern to me, I'm mostly worried about charging too quickly and having "hydrogen issues." And my main concern is keeping the battery in the float-charge state for weeks or months at a time without interruptions or constant re-calibration.

So this question is a two-parter:
1. Has anyone a car battery-recharging design they would personally recommend?

2. I know the max recommended charge rate for deep-cycle batteries is 10% of the capacity. IE: Don't give an 80 Amp-Hour battery more than 8 Amps. What's the rule-of-thumb for automotive batteries?

Hi DigiTan,

why are you worried about the UC3906?

It stops charging at the determined maximum battery voltage and only trickle charges if the battery slowly depletes by self discharging.

To be on the safe side you might add an extra (selectable) current sense resistor for the lowest charge current.

According to my experience batteries can be charged 9 times at high current (C1 or C/2) and each 10th time charge at low current (C/10 or C/12).

I also brought dead batteries back to life by charging them with a 200ms pulse of C50. (lead-acid batteries can give a lot, so why not take a lot?)

Boncuk