Monty
I've had a Link 2000R on my 420 since commissioning (2001). I, too, have 2 8D (AGM) batteries and a start battery. The unit is set up to monitor the 2 house 8Ds. I agree w/ Maine Sail re start battery. The Link does all you want and MORE. Once you have one you will wonder how you got along without it.In addition to digitally reading out all the paramaters you mention; it has the ability to equalize your batteries ( which I don't need now with AGM's).. but, what I do use frequently is the unit's ability to regulate the amount of AC (shore or generator) wattage going into charging the batteries. .. Anywhere from 5 amps to 45amps. So, when sitting at anchor, running your generator, you can increase amperage dilivered to charge batteries to the max; whereas when you tie up and have shore power you can reduce amperage (to say 10amps) so that you can run A/Cs, etc., without overloading shore power breaker(s).At a glance you always know the exact status of your batteries; their charging or discharging status, etc. You can watch increase and decrease of exact amp usage (to tenths of an amp) as you turn lights on and off, the refrig. unit cycles on and off, etc.Makes life with your batteries SO much better.