[encantotom]

hi chuck,

a few things to see if it helps.

and if i get this incorrect, other gurus please jump in.

this is the way i understand how all this charging stuff works.

1. if you are running the engine, the alternator charges both the house and starting batteries through the battery isolator that is in the rear engine bay hatch where the echocharger and merge switch is. there are 3 studs on the isolator. one goes to the starting batteries, one to the house batteries and one to the alternator charging wire. the isolator has diodes that route the charging current to each battery bank, but does not allow the current to flow the other way. what that means is when the engine is running, the alternator charges both battery banks and when the engine is not running, it does no charging but does not allow the two banks of batteries to be tied together so both can discharge together. that is why it is called an isolator. there would be no need for it if you didnt want to charge both banks at the same time with the engine running.

2. the way our rigs are wired is there is another cable that goes from the start and one from the house terminals of the isolator down to the merge switch. that merge switch is the one controlled on the dash to let you merge the batteries together if one bank is too low to either start the genny or the coach engine. merge switch is explained in other places on the forum, but it has 3 positions for a reason. it takes current to trigger the coil to merge the batteries. one way of the switch allows the start batteries to do the triggering and the other position (other than the middle off position) to use the house batteries to trigger the coil.

3. the echocharger or whatever similar trickle charging system is used is to just keep the start batteries charged by stealing a low charging current from the house batteries. that assumes you have shore power or genny running. it does not allow the house batteries to be charged from the engine batteries. it is a one way gig.

you said in your post that when driving the inverter was charging the house batteries that simply is not possible because the inverter gets its power from the house batteries. the genny would have to be running and in that case the inverter would switch itself to standby since the genny would be providing all the house power needed. on shore power the charger portion of the inverter charger would be charging the house batteries only unless you have the merge switch on.

if after sitting disconnected from shore power overnite your engine batteries are at 12.6volts i would say they are charged. the house at 11.8v would make sense if you were running something and there was some discharge happening...like if the inverter was on.

you said the house batteries after equalization settle down at 11volts, but later you said that after sitting disconnected all nite they were at 11.8v. not sure how to reconcile that.

so two suggestions.

first.....load test your house batteries individually. that will tell you easily if they are ok. i have a load tester in my shop i use. but any battery shop or autozone or autoparts place will have one you can use.

second, make sure all your battery connections (big cables) are corrosion free.

third....as for the start battery going low while you are driving. the silverleaf measures from the ddec and the ddec gets it info on voltage from the alternator directly. if that happens again, just run your genny and merge the batteries. i drove a multi thousand mile trip that way when what i thought was my alternator was bad doing exactly the same thing. voltage would swing up and down dramatically. i tested the alternator and it was fine, but i have an external voltage regulator i thought was bad so i ordered a pricey new one. when i went to install it, i discovered the alternator charging terminal on the regulator was totally loose. i replaced the regulator anyway since i had the new one and all was well. so check those connections on the alternator itself or the stand alone regulator if you have one.

your house power systems are normal on shore power because the house batteries are not even needed when on shore power. they can be totally dead and shore power will still work the coach.

your house inverter will not function below a set voltage that is set on your control panel.

hope some of this made sense

tom