Your TrueCharge 40 is a single program, multi-output charger. This means it has three outputs run through diodes all controlled by one voltage program.. Each battery gets exactly the same charge profile.. It says so right in the manual, but the marketing departments try to make it so confusing most folks still don't even understand what they just read..Thank you all for the inputs, even though some of them quite unnecessarily condescending...
I guess will be calling xantrex in the morning to confirm that in fact my chargers is essentially just a one port charger. If it is why do they bother putting 3 outputs? While also specifying that each bank needs to be a minimum of 80ah (in my case since I have the 40a model).
TrueCharge 2:
"Most Truecharge2 Battery Charger models have three outputs that share the full rated current enabling it to charge three different batteries or battery banks that either have the same chemistry or can tolerate the same charge sequence and thresholds. The Truecharge2 Battery Charger can performeither three-stage charging (Bulk, Absorption, and Float) or two-stage charging (Bulk and Absorption)."
Translation:
*"Share full rated current" = One internal power supply
*"Have the same chemistry or can tolerate the same charge sequence" = One voltage regulation circuit for all outputs feeds all batteries the same charge profile.
Almost all chargers are marketed this way, multiple outputs one charger. It essentially saves you from having to leave a battery switch on while at the dock by diode-isolating the batteries at the chargers output bus...
For those who don't have an ACR, Echo Charger or Duo type Charger this works fine for the shore charger in most* situations.
NOTE: *In mixed chemistry installations this type of charger can be a poor fit. Take a GEL house bank that needs 14.1V and an AGM starter that requires 14.6V. If you set the charger to 14.1V the GEL bank will be happy but the AGM will be chronically undercharged and will sulfate earlier than it should. Ideally this type of charger should be used on batteries using identical or nearly identical voltage regulation profiles.
ACR's & Echo type chargers work differently than a multi-output charger by isolating the batteries based on charging voltage either being present or not being present. They do this automatically for wind, solar, hydro and alternator something the shore charger can not do for you, for those other charging sources...
For those who have solar or wind, like yourself, these devices are quite useful as you don't have to be there each morning, or when ever the wind pipes up to parallel the batteries by flipping a switch. All the batteries get charged automatically..
The diodes (sometimes FET's) are there simply to prevent paralleling of the batteries when the charger is off and to prevent pulling 300A through a 10GA to 6GA wire during engine starting or in instances of high in-rush during the use of a windlass or bow thruster... Diodes act as a one-way electrical check valve and only allow current to flow to > a battery from the charger but not from one battery < to > another through the chargers output bus..
All you need to do is use one of the TC240 outputs fed to the house bank and let the ACR do the rest. Some charger makers want to see you jumper the unused outputs, Sterling, but Xantrex does not require this... You can also leave the output connected to the start battery and let the ACR still do what it does and it won't confuse the charger.