Charging a Battery Bank

BFL13 wrote:
One thing is the Trimetric sees everything by way of its shunt. An ammeter would measure just what ever it is on. In my set-up I would need several ammeters I think. I also like the AH counter in the Tri.

I used to post how I didn't need any silly Trimetric until I got one six years ago. Now I think that you can survive without one, but why suffer?

I put my ammeter in the main negative cable between the coach batteries and the coach's 12 volt system (this heavy cable runs from the batteries to the chassis frame). The ammeter sees every electron entering or leaving the battery bank. Net current flow into the batteries makes for positive readings on the ammeter. Net current flow leaving the batteries makes for negative readings on the ammeter.

When I'm charging the batteries I pay no attention to what 12 volt items may or may not be operating in the motorhome (all 12V items draw only very small amounts, anyway, as compared to the charging current flowing into the batteries when charging them back up). When the ammeter reads around 0.5 amps or less net positive current flow I know that the batteries are about full and certainly well enough charged to stop the charging.

My system seems very simple - once the permanent ammeter was installed in the main negative cable for the battery bank (that took some work one afternoon). It just takes glancing at the ammeter occasionally to see how things are going during charging when - camped on hookups using the stock converter, or when drycamping with the Onan powering the stock converter, or when drycamping with the Honda powering the stock converter, or when drycamping with the idling V10's alternator charging the batteries, or when driving down the road with the V10's alternator charging the batteries.

The ammeter is mounted on the cab dash (along with a four-place voltmeter monitoring the coach's 12V system) for easy viewing when camped or driving. I'd use the same system even if I were to replace the stock converter with another type of charger. In fact sometimes I hook a separate portable charger up to the batteries in parallel with the stock converter for faster charging when drycamping ... in which case the ammeter immediately jumps up showing the higher net positive current flow into the batteries.

K.I.S.S. is the only way to go. :C

(all IMHO, of course)