New Battery Shorts Out

[rc0213]

Hi,

I am new to solar panel technology. I bought a 13 Watt portable solar panel, a 100 Watt solar charge regulator and a 12 Volt, 35 Amp AGM battery. I plug in an 750 Watt inverter and then plug in the device. After a while, the battery shorts and the inverter alarm goes off.

Am I doing something wrong? I did find out there are different inverters, and I just bought a sine wave inverter. I, also, bought an extension cord with a surge protector.

Before I reassemble the system, and short out the battery, can someone tell me how to avoid shorting out the battery?

Thanks,

[Logan005]

Battery is not fully charged. have you used an AC charger to fully condition the battery? you may have already damaged the battery. Run a quick load test. If it fails it's already damaged. BTW It could take over a week for a 13 watt panel to top off that battery under typical conditions. the reason your inverter sounds an alarm, your under load voltage is dropping below 10.5 volts, and you should never allow an AGM to drop below 11.5 meaning it has already damaged and continues to damage your battery. I my self use a separate LVD to prevent this.

[inetdog]

You need to be clear about one thing: The battery is not shorting out. The voltage is just dropping below the inverter's low battery sensing level while current is being drawn from it. The inverter will take power from the battery even if you do not have any load connected to the inverter, but with a load connected it could be pulling as much as 70A. That is too much for a 35AH battery.

[jflorey2]

I am new to solar panel technology. I bought a 13 Watt portable solar panel, a 100 Watt solar charge regulator and a 12 Volt, 35 Amp AGM battery. I plug in an 750 Watt inverter and then plug in the device. After a while, the battery shorts and the inverter alarm goes off.

Your battery is not "shorting out." If it did, there would be smoke, heat and other excitement as all the energy in the battery was rapidly converted to heat. You would not hear the inverter alarm since there would be no voltage to run an inverter alarm.

Am I doing something wrong?

You are not charging the battery. A 13 watt panel isn't even close to adequate to charge that battery, and that battery is not adequate to run that inverter.

For a 750 watt inverter you will pull about 70 amps, so you're going to want a ~100 amp hour battery, minimum. To charge that adequately you'll need 100-200 watts of solar. If you want any significant energy out of the system, both the battery and solar system will need to get proportionately larger.

[rc0213]

Thanks for your replies. The reason I believe the battery is shorted out is because I have charged the battery for a few weeks, and it still will not hold a charge.

Logan005, you mentioned "LVD". What is that?

inetdog, so you are thinking my load is pulling too much amps. That is something I need to look into.

[rc0213]

Your battery is not "shorting out." If it did, there would be smoke, heat and other excitement as all the energy in the battery was rapidly converted to heat. You would not hear the inverter alarm since there would be no voltage to run an inverter alarm.

You are not charging the battery. A 13 watt panel isn't even close to adequate to charge that battery, and that battery is not adequate to run that inverter.

For a 750 watt inverter you will pull about 70 amps, so you're going to want a ~100 amp hour battery, minimum. To charge that adequately you'll need 100-200 watts of solar. If you want any significant energy out of the system, both the battery and solar system will need to get proportionately larger.

I see, I guess my system is good for one or two small devices, am I correct?

[SunEagle]

Thanks for your replies. The reason I believe the battery is shorted out is because I have charged the battery for a few weeks, and it still will not hold a charge.

Logan005, you mentioned "LVD". What is that?

inetdog, so you are thinking my load is pulling too much amps. That is something I need to look into.

LVD = Low voltage disconnect. Those are usually a relay that will disconnect the inverter when the battery voltage get to a programmed point above 11 volts.

[mike3367]

rc0213 to put it simply, that 750 watt inverter will drain the battery all by itself in a very short time.

[rc0213]

Thanks for the replies, all.

So, my question is what is shorting my battery? I know it is shorted out because I tried charging it for a few weeks with no success. And, what can I do or use to prevent the short?

[Wy_White_Wolf]

Thanks for the replies, all.

So, my question is what is shorting my battery? I know it is shorted out because I tried charging it for a few weeks with no success. And, what can I do or use to prevent the short?

You overdischarged the battery and damaged it. Nothing you do will bring it back. Before it happens again with a new battery read the stickies on sizing a system.

WWW

[jflorey2]

So, my question is what is shorting my battery? I know it is shorted out because I tried charging it for a few weeks with no success. And, what can I do or use to prevent the short?

Nothing is shorting out the battery. If the battery was shorting out your charger would pull tremendous amounts of current and either blow fuses or overheat. The battery is simply dead due to mistreatment. To avoid this in the future, observe charge and discharge current limits, store it at or close to full charge and maintain it per the voltages from the battery manufacturer.

[Sunking]

There is nothing wrong with your battery or equipment, just poorly designed.

To support a 750 watt Inverer requires a minimum 12 volt 500 AH battery, you only have 35 AH. You need 465 more Amp Hours or 14 more batteries.
To support a 12 volt 500 AH battery requires a 750 watt Solar panel and a 65 Amp MPPT charger. You only have a 13 watt panel. You need 56 more panels.

[Living Large]

How do you define "battery shorts out"? As everyone has stated, your battery is not "shorted". But you stated three times that it is "shorting out". It is impossible to have a conversation if the terms aren't agreed to. I'll add to what others said - if your battery were shorted, there would be a lot more happening than an alarm going off (unless it were the fire alarm in town), and the inverter alarm couldn't go off because the voltage at the inverter would be zero, and therefore the inverter would be totally dead - including its alarm. The first thing to do is figure out if your battery is toast. Then figure out how to match/resize elements of the system so that it can operate properly.

[Logan005]

This is why you can not rely on the Low volt Alarm, on most inverters is already too late, and auto shut down = very heavy lead battery trade in. w/o an adjustable LVD this is going to happen to every battery you hook up to that inverter. If you get another battery for that inverter get at least 100AH and get a nice quality AC powered smart charger like Iota or Samlex. but before you buy anything else read "ALL" of the stickys.

[Sunking]

Short Circuit Voltage = 0 Volts.