Solar panel - overcharging question

Simple answer is yes!
You will need to fit a relatively cheap diode or regulator.

Think of your battery as a rainwater tank and the solar panel as the rain.
(The brighter the sun the greater the outpou from the solar panel.)
The more rain the more the tank fills.
You don't want the tank to overflow - overcharge the battery.
By fitting a regulator you turn the water (electricity) off to the tank (battery) when it is full (charged).
If the battery is overcharged it evaporates the acid.
Regards

Think of it as a switch - as long as the voltage on the output is below a certain level, the regulator will let electricity through.
Once the voltage indicates a charged battery, the regulator either turns off until the charge reduces or will regulate the current tomaintain the charge.

The absolute basic you need is a 7812K regulator for 12V
or LM388K (with a couple of resistors) for a variable regulator. both probably avail from dick smith.
Regards

A 60 watt pannel probally would overcharge a 250amp hour battery in summer. A simple 3 stage Regulator would do the trick. The regulator you've got now might even be that so you probally don't have to worry.

Beware of cheapie regulators. I tried one and found it was leaking charge back into the panel at night. I now use a Morningstar 10 amp, cost around $110.

Cheers,

Jim.

Do you presently have a a regulator?
does it have any specifications written on it?

I use one that I purchased fromJaycar. It's a 20 amp version however they do have a lower rated one. They work really well and actually switch off when a preset voltage is reached. Mine was set to 14.1 Volts and thats about right for most applications.
It checks every 20 minutes or so if more charging is needed.After hours it turns off completely to Prevent any discharge. I am very happy with the regulator.

I use this for my 2 x 40w panels. Hasn't failed and seems cheap but approved by the World Bank for development projects so i believe reasonably robust.

http://www.solazone.com.au/Regulators.htm#Stecca

Other places do sell them this was just the first one i found as a link.

Porl

I am using both the 20amp and 5amp regulators from Jaycar Electronics on two different applications and they both work great, the 5amp is OK for a 60 watt panel and does all the right things (shuts off when battery charged and stops loss of charge at night into panel) One Installation that I am using is in the Flinders Ranges Sth Aus and we only go there once or twice a month and all has been working OK now for twelve months, one other advantage with the Jaycar regulators is that they have LED indications to show what is happening.
5amp is about $26.00 and 20amp is about $65.00

Cheers
Treker

Most solar modules have 36 cells and produce 17-20 volts. These must have an external solar regulator to ensure the battery is adequately charged but not overcharged. The most commonly used in Oz are probably the Plasmatronic range and these cost from $75 - $600.

For the purposes of the system in this thread the basic regulator unit will do. As long as that regulator is fitted the system may be left on permanent charge - subject only to regulator topping up the battery with distilled water. The more costly units have monitoring facilities but may be overkill for this use.

There are also so-called 'self-regulating' solar modules. But their name is misleading. The modules have 33 cells and produce a lower voltage output. They are more or less OK in temperate climates (or where a very small module is used to charge a very large battery) but in Oz they have a tendency to either undercharge or overcharge. Not recommended!

As a matter of hopeful interest (if I may be forgiven thbis small plug) all this is covered in depth in my new 'The Camper Trailer Book' - available around September.
Trust this helps.
Collyn Rivers