12 volt battery solar panel system

[nickbarton]

Hi I am new to solar panels, I have set up a 60 watt solar panel (4 x 15W amorphous weatherproof solar panels) on my shed roof they got into a 10A charge regulator and this is connected to a 12volt leisure battery.
I had this set up and nothing draining the power from it overnight and this morning. The regulator was turned off. When I came to look in there this morning the battery had shot out a load of liquid (water?) from the top. It had not exploded or anything put the stains on the wall show the liquid was released with force.

Is this because the battery had tried to overcharge? Does the regulator always need to be left on? Is this battery now dead?

Thanks for any help

[maple flats]

First of all, those 15 watt Harbor Freight panels are a poor choice, even for starters and the charge controllers are poor too. What is a leisure battery? If lead acid, To know if the battery is junk, you need to test it. Do you have a 12V plug in charger (car)? If yes, hook it up and try to charge the battery. Most likely the battery is good yet, but not if you leave it discharged very long. A lead acid battery does very poorly if run down below 50%, and then it must be re charged right away. If a leisure battery is a sealed lead acid, it may have over charged and the "water" may be electrolyte (battery acid). Use backing soda to neutralize it, and be very careful. If it "boiled over" do not plug it in to charge it. Are you saying the charge controller was shut off but the panels were still connected to the battery? If yes, do those panels tell what their max. voltage output is (should be a label on the back giving 5-6 or 7 values). If so, list what they are.
As for the charge controller, leave it connected all the time, there are diodes to prevent power from being drawn out of the battery after shut down.

[PNjunction]

Hi Nick - sounds like the charge controller fried / cheap, (or was hooked up incorrectly,) losing regulation and overcharging the battery - at least with what little we know.

For lurkers, a "Leisure Battery" is typically a UK / European "cheap and cheerful" deep-cycle lead acid, either flooded or agm. Mostly used for caravaning / camping. Often abused.

BUT, like many worldwide battery outlets, scams abound like dumping heavily discharged old stock, pasting a sticker on a starter-agm and so forth. So finding a reputable dealer is key - don't go by online reviews only. Quite frankly, buy local if you can, and bring a voltmeter with you to make sure you aren't being sold trash.

Nick - what manufacturer / model of controller are you using?

Here is a quick tip to make sure that you are starting out on the right foot with a leisure battery. For an average consumer I highly recommend doing this:

1) Grab a Tecmate-Optimate 6 charger. Should be *easily* found where leisure batteries are sold.
2) Let the Optimate charge your new battery and do this within the refund/return window!

The optimate will tell you right off the bat if you have a damaged battery. If it finishes the charge, let it totally finish the testing period, which means at least 12 hours after the upper-right led flashes for test mode. When the test is over, the combination of solid led's in the upper right will let you know if you have a weak / dud on your hands.

If need be, take a cellphone photo of it as proof to your vendor and demand a refund / return.

I know of no better way for the average consumer to get a handle on what they have, and being able to prove to the usually clueless battery salesman that they sold you a dud. If they aren't aware of Optimate, well that's a big red flag for them.

Then again, it could be that your controller just fried it!