Planning my charging.

[Allan]

At present I have 3 batteries. The start battery is charged by a spit charge system from the alternator so I can forget that. The two domestics are wired together (parallel) to enable them to charged from the Rutland 913 when I'm not there.
As the price of solar panels has come down to £1/w I'm planning to buy an 80w panel and uprate my batteries.
I would like to start planning on what I will need for my final system. I will have 3 or 4 batteries, possibly Trojans, which will be charged by the alternator, 913 and the 80w panel. I would like to be able to switch off the main switches when I leave the boat but still charge all the domestics. I have seen charge controllers with two inputs and two outputs but not 3 or 4.
I hope that all makes sense.
Allan

 

[VicS]

At present I have 3 batteries. The start battery is charged by a spit charge system from the alternator so I can forget that. The two domestics are wired together (parallel) to enable them to charged from the Rutland 913 when I'm not there.
As the price of solar panels has come down to £1/w I'm planning to buy an 80w panel and uprate my batteries.
I would like to start planning on what I will need for my final system. I will have 3 or 4 batteries, possibly Trojans, which will be charged by the alternator, 913 and the 80w panel. I would like to be able to switch off the main switches when I leave the boat but still charge all the domestics. I have seen charge controllers with two inputs and two outputs but not 3 or 4.
I hope that all makes sense.
Allan

When you say that you will have 3 or 4 batteries do you mean all kept separate with different uses or do you mean all linked as one battery bank.

If the latter treat it as one battery. Then you only have 2 to consider, namely the starter battery and the domestic bank.

 

[Allan]

At present I have the two domestics connected together when the power is off. I would like to separate all the domestics but still charge with wind and solar, when I'm away.
Allan

 

[Allan]

I have seen monocrystalline and polycrystalline panels, which are best?
Allan

 

[halcyon]

At present I have the two domestics connected together when the power is off. I would like to separate all the domestics but still charge with wind and solar, when I'm away.
Allan

Why do you want to seperate them ?


Brian

 

[BarryH]

I'm currently looking at the same thing. My battery bank is not as big. The Rutland wind thing that came already fitted to the boat is a pointless waste of time.

I picked up a 30watt panel. I've been told rule of thumb is 10 watts for every 100Ah of battery capacity. The panel is unregulated, but I do have the regulator fitted that the Rutland was connected to. Will the Rutland regulator take the panel do you think?

I can see an unregulated panel over charging the battery if left connected the whole time and the time I want it connected is when I'm not on the boat!

 

[VicS]

I'm currently looking at the same thing. My battery bank is not as big. The Rutland wind thing that came already fitted to the boat is a pointless waste of time.

I picked up a 30watt panel. I've been told rule of thumb is 10 watts for every 100Ah of battery capacity. The panel is unregulated, but I do have the regulator fitted that the Rutland was connected to. Will the Rutland regulator take the panel do you think?

I can see an unregulated panel over charging the battery if left connected the whole time and the time I want it connected is when I'm not on the boat!

1 watt per 10 Ah is the max generally said not to require a regulator but it is also recommended that any panel over 10 watts should have a regulator regardless of battery capacity.

What regulator do you have for your windmill. All the current ones will take inputs from windmill and solar panel simultaneously.

 

[Allan]

Why do you want to seperate them ?


Brian

I'm a little worried about leaving them connected when I'm not there, in case one has a problem and takes the others down. In use I always try to have them connected to ensure they don't go down too low. At present, as said above, the two domestics need a spanner to separate them. I thought these were two important points, am I wrong?
Allan

 

[VicS]

I'm a little worried about leaving them connected when I'm not there, in case one has a problem and takes the others down.

It's a valid point but I would guess most people with several batteries making up a bank leave then connected.

BTW there is a right way and wrong ways of connecting multiple batteries in parallel..

See http://www.smartgauge.co.uk/batt_con.html

 

[William_H]

It's a valid point but I would guess most people with several batteries making up a bank leave then connected.

BTW there is a right way and wrong ways of connecting multiple batteries in parallel..

See http://www.smartgauge.co.uk/batt_con.html

While it would be desirable to separate batteries for testing and if you are concerned about failure as said most people just parallel them and treat them as one.
Regarding the correct wiring for paralleling this is related more to high current loads (starter) where the resistance of the cables is significant. So rather than take the power away from one battery where the second is on an extension of wiring. Here the resistance of the extension will mean the closest battery provides more current than the one on extension. You take the positive from one battery and the negative form the other then parallel the rest. This means that each battery is providing current through the same length of wire. (or each battery is on a partial but equal extension).
olewill

 

[Allan]

Many thanks Vic, I have read that in the past but not considered it recently. I will be making some good leads up when I do the modifications.

 

[little_roundtop]

I have seen monocrystalline and polycrystalline panels, which are best?
Allan

http://www.planetarypower.com.au/solar_panels.htm

http://solar.calfinder.com/ask/which-is-better-2

http://www.solarchoice.net.au/blog/...lline-polycrystalline-or-amorphous-thin-film/