Skip to main content ↑ ↓
Topic: 1200 w Solar  (Read 1776 times) previous topic - next topic

Re: 1200 w Solar

Reply #25 –
Quote from: Pierce & Gaylie Stewart –
The "trickle charger" i'm speaking of is a $24 2 amp Harbor Freight charger. I just have it plugged into the outlet next to the bus where my solar connects to the engine and house batteries. Photos make it clearer. I bought several for the cars and tractor. They work really well. They keep float/maintenance voltage a little above 13V.

Pierce


I tried those on my 4 wheelers.. burned 3 out of 4 batteries up from over charge.. I think the boards were bad in them

Re: 1200 w Solar

Reply #26 –
Quote from: jcus –
Roger, how do you split the solar charge to your two battery banks?

My first design was going to put solar power into the alt post on the Sterling ProSplitR.  This is a smart zero voltage drop isolator that distributes charge based on voltage level of each of the three battery banks, Start,  House 1 and House 2 and in that order.  When the start batteries reach a set level then it moves to the House 1 bank until they reach a set voltage and then on to the House 2 bank.  It checks the Start batteries periodically and if they are below a set point it returns focus to them.  Once all are up to a set level then they get an equal share of the charge current whether it is from the alternator or solar. 

We ran into an issue with power to the Sterling to turn it on.  This is usually an ignition source.  When only on solar it needs to come from the solar charger but that was a bit complicated because we didn't want to feed power back into the ignition circuit and the Sterling Start post is connected to the Alt post by default unless it isolates it while in use.  That needs some diodes and switching to make that happen and I ran out of time. There is a solution, I just need to figure out an elegant one

So I used a Victron ArgoFET isolator, zero voltage drop.  Solar goes into the input side.  Three outputs feed the Start, House 1 and House 2 banks.  The solar charger senses an average voltage across all banks to determine its output.  That output is divided proportionally between the three banks, the lower voltage gets more amps. 

It is pretty easy to change this.  I may remove the start battery connection and jumper the start and House 1 banks.  I am still learning how the two house banks use power.  The House 1 bank (refrigerator and electronics) is a pretty steady load over time.  The House 2 bank (all other 12 v loads and inverter output if it is on) has a much wider load range. 
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN
 

Re: 1200 w Solar

Reply #27 –
Quote from: Roger & Susan in Home2 –
My first design was going to put solar power into the alt post on the Sterling ProSplitR.  This is a smart zero voltage drop isolator that distributes charge based on voltage level of each of the three battery banks, Start,  House 1 and House 2 and in that order.  When the start batteries reach a set level then it moves to the House 1 bank until they reach a set voltage and then on to the House 2 bank.  It checks the Start batteries periodically and if they are below a set point it returns focus to them.  Once all are up to a set level then they get an equal share of the charge current whether it is from the alternator or solar. 

We ran into an issue with power to the Sterling to turn it on.  This is usually an ignition source.  When only on solar it needs to come from the solar charger but that was a bit complicated because we didn't want to feed power back into the ignition circuit and the Sterling Start post is connected to the Alt post by default unless it isolates it while in use.  That needs some diodes and switching to make that happen and I ran out of time. There is a solution, I just need to figure out an elegant one

So I used a Victron ArgoFET isolator, zero voltage drop.  Solar goes into the input side.  Three outputs feed the Start, House 1 and House 2 banks.  The solar charger senses an average voltage across all banks to determine its output.  That output is divided proportionally between the three banks, the lower voltage gets more amps. 

It is pretty easy to change this.  I may remove the start battery connection and jumper the start and House 1 banks.  I am still learning how the two house banks use power.  The House 1 bank (refrigerator and electronics) is a pretty steady load over time.  The House 2 bank (all other 12 v loads and inverter output if it is on) has a much wider load range. 
I was thinking of using one bigger combiner to replace isolator [already have] and using 2 smaller ones on 2 other banks as a basic open/close type of relay, close on charge situation, open when no charge. Solar would only need to feed one bank and combiners would allow charge to two other banks,  I may have to rethink this and may be over simplifying the situation. 
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.