Comments on Changing by Battery arrangement

[timjet]

JD wrote:

*I think that is your best option.* You do realize that the way you have it set up that the house charger is going to split it's total 50 amps or what ever yours is,*by three.* So as an example a*50A*charger gives you 16.6 amps per leg.* Also the Gen set battery*is being charged like the AGMs at 16.6 amps.* You might consider an Echo from the*start battery to the Gen set which is the least used battery and splitting the house charger to two legs like the two Alts.* That would give you 25 amps per bank using my example of a 50 amp house charger.* When the Echo sees the Gen set as fully charged, as it will most of the time, the*start will get as much of the 25 amps as it needs.

*JD, it was my understanding that my 3 bank 30 amp Charles charger will put out a max of 30 amps to one bank if the other two banks are full, otherwise it splits the bank charge as necessary to a combined total of 30 amps, less some line loss.

But my battery charger is really not part of this equation because of my high amp fridge. At 300 amps per daily use split between two charging periods that means I have to replace 150 amps twice a day. My 30 amp battery charger would run off the genset 10 hrs per day to keep up. Not really feasible.

I'm working with Tony Athens to determine the amp output of my alternators. He thinks they're 100 amp units but he's trying to find out for sure, Cummins did not use the same alternators on all it's 6BT's.

So to make a reasonable effort to replace 150 amps twice a day I'm running the engines for 45 minutes which should put back most of the 150 amps used per charging cycle.

It's rare we spend more than 2 days at anchor without moving the boat so this seems the most economical solution for the time being. Spending big boat bucks for isolators, echo charges, battery chargers and monitors will help, but simply running the engines for 45 minutes at 1000 rpm twice a day seems a simple economical solution.

 

[FF]

but simply running the engines for 45 minutes at 1000 rpm twice a day seems a simple economical solution.

Not if you figure engine life.

BUT since most yachties seldom wear out an engine in a lifetime , it will be the next owners problem.

The real solution would be better fridges , or a different energy storage system.

Batteries , even AGM take time and only hold so much energy, and do not get full that quickly..

Perhaps a eutetic system ( Coldplates) might work better.

And there is always Propane , for months of quiet.

FF