HELP: Inverter is draining battery almost instantly! Why?

[spoon]

Also, are you aware that an inverter can take power even with no loads? Do you turn it off when not in use? An inverter can drain a small battery if left on 24X7.

Yep, the inverter is only switched on when needed. With regards the other post, the last few weeks here have been quite good sunshine wise... I would have expected a 250w panel to charge 20% of my battery no trouble, no?

Basically I'm trying to pinpoint what in the system is not working, as I'm on a budget (isn't everyone) I can't change the whole set up for better kit just yet. I'm really hoping that it isn't the new battery as I've just forked out £70 for that.

So, advise is to make sure battery is ok forst.. I do this by checking voltage this evening when no load, and then again say in 24 hours to see there has been no drop?

Also, potentially look at getting an MTTP CC.

I would like to change the inverter too, even if it isn't to blame... It has an automatic fan which is on constantly, horrible noise.

Why, in the evening when the inverter took the battery to red, did the CC light go back to green once the inverter had been turned off... There was nothing charging it?

[lkruper]

Sometimes running in sunlight, sometimes running at night ( I meant via inverter btw). Never any problems either way, 110ah battery should comfortably run a laptop for a night, no?

No, sometimes it takes afew days for it to get back to 'flashing green' on the CC, but it usualy always gets there in the end.

Also, are you aware that an inverter can take power even with no loads? Do you turn it off when not in use? An inverter can drain a small battery if left on 24X7.

[lkruper]

Sometimes running in sunlight, sometimes running at night ( I meant via inverter btw). Never any problems either way, 110ah battery should comfortably run a laptop for a night, no?

No, sometimes it takes afew days for it to get back to 'flashing green' on the CC, but it usualy always gets there in the end.

Lead acid batteries are not designed to sit without having a full charge. If you say it took a few days to get to full charge it is possible that you are losing capacity because of sulfation. This is a permanent loss of capacity of the battery. I have heard that in as little as a week one can lose capacity, but if your battery is frequently not getting charged back to 100% every night that is troubling. When this happens, it may appear that a battery is getting charged based on the lights on your charge controller, but that does not mean your battery is not sulfated.

If you watch TV at 65w for three hours and run 3X3w leds for 6 hours that would use about 20AH of your battery or about 20%. That is good. But to recharge you would need full sun for an hour or two (to make up for inefficiency in charging) to get it replaced and then depending on your controller from 2-4 hours or even more in absorb to get to 100%.

This rate of charge is also greatly dependant upon the season of the year, weather and orientation of the panel to get the maximum output from the panel. I agree with a previous poster that your grid-tie panel may benefit from an MPPT controller, particulary since you are not getting charged back up to 100% frequently.

[spoon]

When you say laptop via charge controller, do you mean from a load during full sunlight so that the battery is not used at all?

Also, has your battery always been fully recharged 100% each and every night and if not, how long did it go before getting fully charged?

Sometimes running in sunlight, sometimes running at night ( I meant via inverter btw). Never any problems either way, 110ah battery should comfortably run a laptop for a night, no?

No, sometimes it takes afew days for it to get back to 'flashing green' on the CC, but it usualy always gets there in the end.

[lkruper]

No, nothing like that. We use around 9w of lighting in an evening (3x 3w LEDS) for maybe 5- 6 hours tops. Then the laptop was used via charge controller (sparingly). The length of a movie (lets say 3 hours) every 3 nights or so...


We really don't use alot of power... I don't see how we would have used up the cycle life of a almost new battery.

When you say laptop via charge controller, do you mean from a load during full sunlight so that the battery is not used at all?

Also, has your battery always been fully recharged 100% each and every night and if not, how long did it go before getting fully charged?

[spoon]

So, how many hours did you run your loads when you first started using it? Do you estimate about 100w for the loads?

No, nothing like that. We use around 9w of lighting in an evening (3x 3w LEDS) for maybe 5- 6 hours tops. Then the laptop was used via charge controller (sparingly). The length of a movie (lets say 3 hours) every 3 nights or so...


We really don't use alot of power... I don't see how we would have used up the cycle life of a almost new battery.

[lkruper]

We've lived with the system for a while (over 6 months on an old battery and 2-3 months on the new Numax), it's only in the last 2-3 weeks that there has been this problem.

I charged it with my standard car battery charger in the workshop, on normal speed (I think it's 10a from memory).

After a good mains charge, and when hooked up to the caravan it was flashing green (i.e. 100% charged).

So, how many hours did you run your loads when you first started using it? Do you estimate about 100w for the loads?

[spoon]

Also: When you first hooked up your laptop how long did it run before you had a problem? From what I see on the net your battery should get 500 cycles at 70% DOD. You say you trickle charged it. With what charger?

We've lived with the system for a while (over 6 months on an old battery and 2-3 months on the new Numax), it's only in the last 2-3 weeks that there has been this problem.

I charged it with my standard car battery charger in the workshop, on normal speed (I think it's 10a from memory).

After a good mains charge, and when hooked up to the caravan it was flashing green (i.e. 100% charged).

[lkruper]

Nope, didn't get any usage instructions with battery.

Also: When you first hooked up your laptop how long did it run before you had a problem? From what I see on the net your battery should get 500 cycles at 70% DOD. You say you trickle charged it. With what charger?

[spoon]

I could not find anything about your battery online which specified the charge rate. Did you get a usage guide which tells what amps it likes? 10% is safe, and 20% good for some AGMs. Your charge controller is 20 amps. that is approximately 0.2C where C = 110AH.

Nope, didn't get any usage instructions with battery.

[lkruper]

Yep, I'm pretty sure it is set to the correct battery type. I will check again though. My CC is actually a landstar (I think), but is identical to the one I linked in every respect that I can see.

My battery is definately 'sealed' lead acid... Not flooded then.

The CC is quite simple. The LED flashes slowly green when battery is full, stays green when mostly full and goes orange to red when overdischarged.

Mine tends to always be solid green, sometimes it flashes. With a few full days of strong sun and no useage.

I could not find anything about your battery online which specified the charge rate. Did you get a usage guide which tells what amps it likes? 10% is safe, and 20% good for some AGMs. Your charge controller is 20 amps. that is approximately 0.2C where C = 110AH.

[spoon]

When you first hooked up your laptop how long did it run before you had a problem? From what I see on the net your battery should get 500 cycles at 70% DOD. You say you trickle charged it. With what charger? I see that Numax has their own brand of charger that is a 10 amp charger for a 110AH battery. So evidently a charge rate of 10% of the AH capacity is good for this battery. When you put your spare battery on the inverter, make sure it has been completely charged first and also measure the voltage at rest before you use it.

I see that your 20 amp charge controller has this feature:
Automatic 12V/24V voltage detection and temperature compensation for three battery types (sealed, gel, flooded)

I presume you have it set for sealed? Also, when you charge, does the charge controller finish he charge and indicate it has finished with the leds?

Yep, I'm pretty sure it is set to the correct battery type. I will check again though. My CC is actually a landstar (I think), but is identical to the one I linked in every respect that I can see.

My battery is definately 'sealed' lead acid... Not flooded then.

The CC is quite simple. The LED flashes slowly green when battery is full, stays green when mostly full and goes orange to red when overdischarged.

Mine tends to always be solid green, sometimes it flashes. With a few full days of strong sun and no useage.

[lkruper]

Ok, well by the time I get back this eve it will have been dark for over an hour with nothing being drawn, so will test battery voltage then.

I also have an identical battery bought at the same time for emergency back up. I will try putting that on, but I'm sure i tried this previously and had the same result.

When you first hooked up your laptop how long did it run before you had a problem? From what I see on the net your battery should get 500 cycles at 70% DOD. You say you trickle charged it. With what charger? I see that Numax has their own brand of charger that is a 10 amp charger for a 110AH battery. So evidently a charge rate of 10% of the AH capacity is good for this battery. When you put your spare battery on the inverter, make sure it has been completely charged first and also measure the voltage at rest before you use it.

I see that your 20 amp charge controller has this feature:
Automatic 12V/24V voltage detection and temperature compensation for three battery types (sealed, gel, flooded)

I presume you have it set for sealed? Also, when you charge, does the charge controller finish he charge and indicate it has finished with the leds?

[createthis]

How simple is that to do, what bits will I need?

This is a good tutorial: https://youtu.be/dZzinsfI2Y0

I have no idea where you find those fat battery cables. I suspect lots of places carry them. 6 AWG would be more than enough, I'd think. Check around on the internet for 12v cable sizing based on the number of amps you plan to draw from the inverter and the number of feet between the batteries, then find somewhere to source the cables.

[spoon]

You might want to wire that battery into the circuit permanently in parallel. Lead acid batteries die the true death pretty quickly if they are not topped off regularly. Plus, then you'll have twice the capacity.

How simple is that to do, what bits will I need?