Just note, regarding accuracy on the voltage reading - I would suggest checking against a known-good meter to establish a "calibration" offset, when cold and again when warm. They are often a tenth or two off when warm, but I've had a handful of similar meters in vehicles and I've noticed they tend to be further off (half a volt or more sometimes) when the meter itself cold, which might lead to concern about the battery or alternator when in fact it's just an inaccurate reading.