please assist me!!!!!! I am losing my mind.

A month ago I bought a Mecer 720w inverter with a 100ah gel battery. they battery wasn`t even giving me a full hour after being fully charged. I swopped the battery for a different battery and the same issue. I bought a different battery from a different supplier and its doing the same thing. All I ran was a 55inch led tv and a 9 watt led bulb. 

when I put the tv on the battery indicator drops instantly from 100 to 75% is this normal? I thought it should stay on 100 for atleast some time. with the tv and 9 watt bulb the load goes from 23 to 50%. this also doesnt seem normal to me. please assist

44 minutes ago, jonathan.pakiri said:

when I put the tv on the battery indicator drops instantly from 100 to 75% is this normal?

It's probably to be expected. The inverter guess state of charge by the battery voltage, and the load is enough to make the battery voltage drop considerably. It's interpreting this as a reduction in state of charge from 100% to 75%.

Your inverter is a 12 V model. These are hard on batteries, especially lead acid batteries. There is also the premature float bug, which chronically undercharges the battery if charging from solar. Constant load shedding is also hard on batteries, as these inverters let the battery run down far too far for good battery life. They are designed for areas where power outages are rare, so it's OK to occasionally let the battery run down to low states of charge.

Sadly, there is no easy or cheap way around this.

44 minutes ago, jonathan.pakiri said:

with the tv and 9 watt bulb the load goes from 23 to 50%.

That does sound like a lot. Maybe your TV is using more power than most. Is it possible to use a wattmeter to find out how much power it's actually using?

Does your inverter show you power usage in watts? The larger models certainly do.

Edit: I'm assuming that this is a 1 kVA 720 W Axpert; maybe it's not even an Axpert? Do you have a model name/number for the inverter?

Edited March 15, 20232 yr by Coulomb

1 hour ago, Coulomb said:

It's probably to be expected. The inverter guess state of charge by the battery voltage, and the load is enough to make the battery voltage drop considerably. It's interpreting this as a reduction in state of charge from 100% to 75%.

Your inverter is a 12 V model. These are hard on batteries, especially lead acid batteries. There is also the premature float bug, which chronically undercharges the battery if charging from solar. Constant load shedding is also hard on batteries, as these inverters let the battery run down far too far for good battery life. They are designed for areas where power outages are rare, so it's OK to occasionally let the battery run down to low states of charge.

Sadly, there is no easy or cheap way around this.

That does sound like a lot. Maybe your TV is using more power than most. Is it possible to use a wattmeter to find out how much power it's actually using?

Does your inverter show you power usage in watts? The larger models certainly do.

Edit: I'm assuming that this is a 1 kVA 720 W Axpert; maybe it's not even an Axpert? Do you have a model name/number for the inverter?

If more people just knew someone to help or prepared to get a battery protector to switch these inverters of at a suitable voltage for lead acids they can stretch the battery life perhaps 3 fold. Yes LS remains a killer with these units. 

2 hours ago, Coulomb said:

It's probably to be expected. The inverter guess state of charge by the battery voltage, and the load is enough to make the battery voltage drop considerably. It's interpreting this as a reduction in state of charge from 100% to 75%.

Your inverter is a 12 V model. These are hard on batteries, especially lead acid batteries. There is also the premature float bug, which chronically undercharges the battery if charging from solar. Constant load shedding is also hard on batteries, as these inverters let the battery run down far too far for good battery life. They are designed for areas where power outages are rare, so it's OK to occasionally let the battery run down to low states of charge.

Sadly, there is no easy or cheap way around this.

That does sound like a lot. Maybe your TV is using more power than most. Is it possible to use a wattmeter to find out how much power it's actually using?

Does your inverter show you power usage in watts? The larger models certainly do.

Edit: I'm assuming that this is a 1 kVA 720 W Axpert; maybe it's not even an Axpert? Do you have a model name/number for the inverter?

Not Axpert, but Voltronics for sure by part numbers and pcb design style. Simulated sine, not pure.  Two transformers, one is hf  dc-dc, one is charger. 

The lead acid 'SOC' and load power is merely a 4 or 5 bar graph display. 

There is option for solar, which is a module that is added. 

There is a 1440W version also. 24v.

EDIT: this was my first inverter for loadshedding,  tough, still working. This is where I learned lead acid storage and the dogs pooh on the grass is the same thing. 

 

 

Edited March 15, 20232 yr by BritishRacingGreen

Just now, BritishRacingGreen said:

Not Axpert, but Voltronics for sure by part numbers and pcb design style. Simulated sine, not pure. 

 

 

2 hours ago, jonathan.pakiri said:

 

when I put the tv on the battery indicator drops instantly from 100 to 75% is this normal? I thought it should stay on 100 for atleast some time. with the tv and 9 watt bulb the load goes from 23 to 50%. this also doesnt seem normal to me. please assist

I doubt that the 50% is correct but if it is the 1x100Ah is too small to run 2 hrs from that battery. 2hrs will mean 720Wh and a perfect 100Ah should not be discharged before being fully charged again by more than 600Wh.

Always good to actually measure the power used from the TV which is your main load. 

We see the common assumption that a 42inch LED TV uses around 60W. I measured one the other day for a family member and it used 150W. I thought it very high as a 42inch plasma known to chow power uses about 200W.

12 hours ago, Scorp007 said:

Always good to actually measure the power used from the TV which is your main load. 

We see the common assumption that a 42inch LED TV uses around 60W. I measured one the other day for a family member and it used 150W. I thought it very high as a 42inch plasma known to chow power uses about 200W.

Agreed. And it's seldom JUST a TV, there's usually a decoder or a MiBox or something like that. They don't take up a lot of power, but they take up some.

Anyway, my mother has one of these inverter/battery combinations. Her TV is 40 inches, and that TV and an Explora draw a steady 170W from the inverter, most of thatbeing the TV. So I don't believe this rule of thumb that TV = 60W. The draw is also very dependent on settings. If you have the brightness turned up, if you have the backlight turned up, then it could consume more. 

@jonathan.pakiri maybe there is an eco mode on your TV? This might reduce the load a bit.

But generally I agree that the single battery is maybe not enough. Also batteries are not just batteries. I know folks who have used car batteries with these inverters. That doesn't work well.