House battery and solar panel sizing

[windtrader]

Windtrader have you considered L-16 batteries in place of the golf cart batteries?  Same foot print but about 4" taller and about 400 ah.

Last I looked a bunch more money. The interstates are 85 each. If the last a couple years I'll be satisfied. Just bought the bus so trying to keep as much in the war chest for future expenses I'm sure will come knocking

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[buswarrior]

I'd get good at caring for inexpensive batteries, then, once your habits have proven to be battery friendly, consider graduating to expensive batteries?

You can murder expensive batteries in pretty much just as short a time as inexpensive batteries...

when the "trial" batteries are still doing their job in 7 years, you have arrived?

happy coaching!
buswarrior

[windtrader]

From the documents on my bus, it seems the bus alternator charges the house batteries if the switch is engaged and just sends power straight in. My understanding is 3 stage charging is the best way and the house batteries do charge that way via the inverter/charger.

So, yes, I need to figure it all out and actually get a good idea of my own pattern of use before buying expensive batteries. 

[buswarrior]

This is a long story of everything you didn't want to know about internally regulated alternators, externally regulated alternators, the bias of manufacturers, and needing to get your house bank re-charged, vs topping off a start battery.

It is a marine focus, but the end result is the same for a busnut. Get a beverage before you start this one.

https://marinehowto.com/automotive-alternators-vs-deep-cycle-batteries/

Summary: a regular internally regulated automotive alternator has a really bad habit of trickle charging your house bank when you need it to do more.

Our big coach alternators are externally regulated, and just as limited. But we're over half way there, we have the alternator, we just need the regulator

Upgrading the external regulator on our big Delco alternators, dedicated to the house bank, with temp sensor for both the alternator and the battery bank, can really do the job well, if charging on the move will be your style of camping. Let an add-on alternator take care of the start batteries?

happy coaching!
buswarrior

[windtrader]

BW - Thanks for the link. The general theme is most motor connected alternators undercharge the battery bank. Tomorrow, I'm going to hook up and volt/current meter in the house battery loop. Will check what is going on with both the alternator charge as well as the ouput from the 3 stage charge/inverter.

Once some solar energy is installed and controlled by a charge controller to the house battery pack, that should allow for proper amount and charge rate. In the meantime, I can make sure proper bulk/absorption/float volts/current is going to the batteries via the inverter/charger.

If the alternator tends to undercharge, maybe it can just stay that way as it not harming the batteries while charging.

[Lee Bradley]

One of the problems with non-stock regulator for the big Delco alternators is they require up to 10 amps for the field while most other alternators don't exceed 5 amps.  Make sure the regulator you get can handle that load.

[buswarrior]

http://www.balmar.net/?product=regulator-mc-624-h

Balmar's 24 volt multi-stage regulator is programmable and will do just over 300 amp alternator/ 10 amp field.

Not cheap, but it'll do exactly what you tell it to do.

Dream for the lottery to come in?

happy coaching!
buswarrior

[Lee Bradley]

I looked it the Balmar regulator and finally decided that I am just not going to drive enough hours to need that much regulation.  I added a small 28 volt alternator for the start batteries and left the big boy set at 27.3 volts. I don't think that voltage will hurt the AMG batteries for the number of hours I'm going drive and the Trace 4024 can take care of them when I'm on the pole or generator. 

[windtrader]

OK. Great progress today. Got the new battery bank in and running. Now using 4 x 6v 210Ah Interstate GC2 deep cycle batteries, all in series. Never realized just how dead the old house battery bank was until this new bank. Like a new coach, God, let there be light and there is light. LOL. Loving the difference, recording the voltage to get some sense of estimated vs actual drawdown.

Will check the alternator tomorrow. I thought it was a 50DN? upgrade but could not find the receipt. Going to have to go take a look.

So much nicer when you can see and your beer stays cold. LOL