Solar Panel Regulators

Submitted: Friday, Jul 04, 2003 at 12:19

ThreadID: 5811 Views:2402 Replies:6 FollowUps:3

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Leroy

Hi all,

Just wondering what regulators are using on their solar panels? Are the ones from *ick Smith/Jaycar any good. Jaycar have a German made 12V/5A reg that appears like it will do the job! Comments welcome.....of course!

Leroy

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Reply By: stillthinkinaboutit - Friday, Jul 04, 2003 at 13:15

Friday, Jul 04, 2003 at 13:15

Hi Leroy,

I am using a Plasmatronics PL20. This costs around $300, it is a 20 Amp unit, fully programmable, 3 Stage Charge + Absorbtion Cycle, has low voltage cutout, records A/Hour In, records A/Hour Out, shows State of charge etc.

The cheaper ones will work but will only allow 5 amp charge and only have a single stage charge. It really depends on what sort of setup you want to have. If you are using relatively cheap batteries the cheap regulators are probably OK.

But if you are using expensive deep cycle or AGM batteries as I do ( my batteries cost around $ 800 ) then it pays to look after them with a better quality unit. I also use the regulator for charging the batteries from the mains, all you need is a 12V 20A transformer, a bridge rectifier and a capacitor ( all up cost around $ 90 ) and then you have a good 3 stage battery charger as well.

AnswerID: 24194

Follow Up By: Leroy - Friday, Jul 04, 2003 at 15:03

Friday, Jul 04, 2003 at 15:03

Sounds flash! I like the recording of A/hours in and out but I don't think I need to be that exact. What does the 3 stage charge involve?

Leroy

FollowupID: 16278

Follow Up By: stillthinkinaboutit - Wednesday, Jul 09, 2003 at 09:40

Wednesday, Jul 09, 2003 at 09:40

Hi Leroy,

A 3 stage charger has as the name suggests, 3 stages to the charging cycle.
First is the BULK charge, this cycle typically runs until the battery reaches 85% of full charge, charging current is typically very high during this cycle and the voltage is not constant.
Second is the ABSORPTION charge, a constant charge voltage is now applied until the battery reaches 100% charge. The constant voltage limits the charging current and prevents excessive gassing of the battery which results in loss of electrolyte.
Third is the FLOAT charge, a lower charge voltage is applied to the battery such that current supplied is minimal and gassing does not occur, it is safe to leave the charger in this mode indefinitely.
An optional EQUALIZATION charge can also be applied periodically if you are using wet batteries, say once a month, this boosts the charge voltage to something around 15 or 16 volts and causes the electrolyte to gas, theory is it will equalize the charge between cells. Not for use with sealed batteries.

As an example for an AGM battery:

BULK charge voltage can be from 10.5 to 14.5 volts at a current up to 75% of the batteries capacity. So for a 100AH battery charging current could be as high as 75 Amps ( for a 100A/H wet cell battery you would normally limit current to 10 or 15 Amps ).

ABSORPTION Charge voltage is constant voltage and is in the range of 14.2 to 14.7 volts.

FLOAT Charge voltage is constant voltage and is in the range of 12.8 to 13.8 volts.

The above is an example for an AGM battery.
You would set the various voltages and current limits to suit the type of battery you are using, the manufacturers data sheet should state the ideal charging parameters.

The Plasmatronics PL series regulators also have some standard programs installed if you do not wish to go into great depth, although the units are very easy to program.