Charging

[wheels 543]

I'm just assuming that if I link them they'll all charge at once.

No they wont.

And as for those VSR devices, I have said it before, they are a waste of time. OK for a fizz nasty, or a very small simple yacht set up. Crusiing boats should never use them. This is because they switch at a a Voltage that is not best for fully charging a battey. Then they switch in a bank that is at a different level and the alternator will not charge correctly, resulting in the Start bank being over charged or the House bank never getting enough.

[Guest]

Opps, if BM is talking 'all together' being house and starting at once, Wheels is right.

 

That Dicky Smith I grabbed in a hurry worked good. Mind you it was being powered at 1/2 of what is said it could handle so maybe that had something to do with it. There are some pretty large and I'd say very hard to prove claims made by some in the Solar world, mind you no different than in the chain world at the moment or most others I'd guess.

 

And due to NZ having more Sunbugs it does mean some systems are being pushed a lot harder than most think they are.

 

Here's one that should be good for panels up to 60W odd. It's made by a respected name in the game.

http://www.trademe.co.nz/Business-farming-industry/Industrial/Generators-power-supply/Solar/auction-339031533.htm

 

I'll suss what one like mine costs. Thinking 60 ish but I haven't sussed for a while.

[Guest]

I don't understand why they won't all charge together but I'll go with it and not link them. Either charge the house or the start through a controller, got it.

[wheels 543]

The problem Zen, is in the Resistance of the batteries. As a Battery charges, it's resistance to that current changes. For example, you start the engine and the Alternator charge gauge is reading quite High. As the Charge climbs, the Gauge starts dropping back. So batteries at different charge states will have provide a different load to a charger. Resistance also changes due to things like Type, Capacity, Age, Temperature, and Cable size and length connecting them all, including the negative Cable. So the result is that a Battery presenting a bigger load to the charger is going to take the greater share in charge over anything of lesser load.

Even if all are connected in a Bank of equal everything, it is not recommended to replace one battery if over 1 yr old. That is all it takes to upset the charge balance of the entire bank and the new battery will boil it's head off. In fact, if you have a bank and one happens to fail in warranty, the supplier should replace the entire bank under warranty and not just the one that failed.

[Guest]

http://www.jaycar.co.nz/productView.asp?ID=MP3128&CATID=7&form=CAT&SUBCATID=912

 

Nice little unit and reasonably priced - also all the techie bits are set in epoxy so good for damp environments.

[Guest]

Word of warning on controllers -

 

Been sussing for a 24v one, for yet another bloody project, and noticed many will only take up to 30-32V input. A bugger when you have a 44V output panel as I have. Interesting I thought so sussed some 12V ones and this is where the warning comes in - many 12V panels output 22-23V and some controllers will only take a 17-19V input.

 

Watch for that. I don't know what would happen but it probably wouldn't be good.

 

That Jaycar mentioned above is fine, it takes up to 26V, nice.

[wheels 543]

Those Voltages are only seen in an open circuit situation KM. In other words, no load connected. As soon as you connect a load, being the Regulator, that voltage drops dramaticaly and the Reg should never see anything higher than it was designed for. To be honest, I don't know why on earth they actually state the OC voltage. It doesn't mean anything to anyone, because it is not real world. It is also one reason why panels are stated in Watts, because they produce Power (Current and Voltage) in respect to the load (resistance). In the best possible light conditions, the panel produces power and how much power depends on the resistance to that power. So to get the magic figure the panel states it is, you have to have just the right load resistance. Anything different to that and you have a different power output. One of several reasons why in the real world, you don't always get what the panel says it should give.