Mecer 2400VA Inverter (Community Support)

wingnut771

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Joined
Feb 15, 2011
Messages
7,861
It's my entertainment to game, my wife enjoys watching her series on netflix. I get bored of netflix quite quick.

I'm sure games like dota2 don't use 400-450w , could be wrong. Those omnipower 120ah are heavy, it's hard to buy them and ship, shipping is rough.
think i'm going to go for this as they're just down the road so i can go fetch:
1500 cycles @ 50% DOD.
 

Iwojima

Expert Member
Joined
Jan 16, 2007
Messages
2,462
The 720w inverter i feel will maybe come short at times, thats why i went for the bigger unit
Have you measured your peak and average wattage draw for the devices you'd like on for the full 3 hours? You'd be surprised how efficient modern PC's are.
 

Charlesjjm

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Joined
Dec 2, 2014
Messages
241
This thread proved to be most helpful. Thank you to all the comments/suggestions/advice. I picked up my battery today, just waiting for the inverter to arrive, then I'll be ready for load-shedding. Just wanting to run my TV and fibre router and maybe one lamp.

Battery - Vision 100Ah 12V Deep Cycle AGM Battery ( Extra Heavy Duty 6FM100Z-X )
Inverter - Mecer 1200Va 720W 12V Inverter | IVR-1200LBK
 

BoxFish

Active Member
Joined
Jun 11, 2019
Messages
42
i plug the wifi router into 1 of the 12v batteries and plug the wifi box into the other batteries
the reason i am running in series is because i have a 24v CTEK charger
Just be cautious when loading/discharging the batteries individually then charging them in series. Eventually, your batteries will go out of balance and one battery will overcharge.
I assume you balance the load between the batteries?
 

Papa Smurf

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Aug 2, 2016
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Just be cautious when loading/discharging the batteries individually then charging them in series. Eventually, your batteries will go out of balance and one battery will overcharge.
I assume you balance the load between the batteries?
no, i have been naughty and not balanced

i do have a dual voltmeter at home that i must wire up so i can see what each battery is doing.

Thanx for the tip, i never thought of that
 

wingnut771

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Just be cautious when loading/discharging the batteries individually then charging them in series. Eventually, your batteries will go out of balance and one battery will overcharge.
I assume you balance the load between the batteries?
don't the batteries balance themselves?
 

wingnut771

Executive Member
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Feb 15, 2011
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i assumed it would by using a 24v charger (but im no rocket scientist)
i'm no rocket scientist either but i think it's only an issue when making the bank that battery voltage has to be the same before joining, but once joined they should equalise, i know it like this for parallel, not sure on series.
 

Papa Smurf

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i'm no rocket scientist either but i think it's only an issue when making the bank that battery voltage has to be the same before joining, but once joined they should equalise, i know it like this for parallel, not sure on series.
me either
both batteries are draining the same load
1amp
i will check tonight when i get home
i havent charged them in 8 days and need to tonight as i saw the voltmeter across both this morning was 25.0v
 

BoxFish

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42
Just an aside

Batteries in parallel are forced to the same voltage. Batteries in series are forced to the same current. So each battery in a series chain can sit at a different voltage. The sum of the voltages is all the charger will see. So one battery could be flat and the other overcharged but the total would look fine (up to a point). Batteries in series do eventually go slightly out of balance (due to different capacities and self discharge) but this is usually a long term process. Putting unbalanced loads on each battery aggravates the imbalance. A very tiny load on each battery just takes a lot longer before the imbalance becomes apparent.

Flooded lead acid cells typically tolerance a bit of imbalance as they shed the excess energy via heat and gassing. You lose some electrolyte which can be replaced. However this you cannot do that with sealed/maintenance free lead acid or with lithium. Out of interest, some BMS systems for lithium actually "balance" the cells with a special circuit that measures each cell individually and pulls them back into balance by either dumping or redistributing some of the energy.
 

thechamp

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Feb 26, 2011
Messages
27,211
Just an aside

Batteries in parallel are forced to the same voltage. Batteries in series are forced to the same current. So each battery in a series chain can sit at a different voltage. The sum of the voltages is all the charger will see. So one battery could be flat and the other overcharged but the total would look fine (up to a point). Batteries in series do eventually go slightly out of balance (due to different capacities and self discharge) but this is usually a long term process. Putting unbalanced loads on each battery aggravates the imbalance. A very tiny load on each battery just takes a lot longer before the imbalance becomes apparent.

Flooded lead acid cells typically tolerance a bit of imbalance as they shed the excess energy via heat and gassing. You lose some electrolyte which can be replaced. However this you cannot do that with sealed/maintenance free lead acid or with lithium. Out of interest, some BMS systems for lithium actually "balance" the cells with a special circuit that measures each cell individually and pulls them back into balance by either dumping or redistributing some of the energy.
Nice explanation.
 

wingnut771

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Joined
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7,861
Just an aside

Batteries in parallel are forced to the same voltage. Batteries in series are forced to the same current. So each battery in a series chain can sit at a different voltage. The sum of the voltages is all the charger will see. So one battery could be flat and the other overcharged but the total would look fine (up to a point). Batteries in series do eventually go slightly out of balance (due to different capacities and self discharge) but this is usually a long term process. Putting unbalanced loads on each battery aggravates the imbalance. A very tiny load on each battery just takes a lot longer before the imbalance becomes apparent.

Flooded lead acid cells typically tolerance a bit of imbalance as they shed the excess energy via heat and gassing. You lose some electrolyte which can be replaced. However this you cannot do that with sealed/maintenance free lead acid or with lithium. Out of interest, some BMS systems for lithium actually "balance" the cells with a special circuit that measures each cell individually and pulls them back into balance by either dumping or redistributing some of the energy.
summed it up nicely.
 

Papa Smurf

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don't the batteries balance themselves?
just got home and measured each battery with my Fluke
12.48v and 12.67v after 8 days
mmmmmm, not what i wanted to see
just plugged in 24v charger, lets see what happens and if they both balance themselves out equally
 

Papa Smurf

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Joined
Aug 2, 2016
Messages
20,409
Just an aside

Batteries in parallel are forced to the same voltage. Batteries in series are forced to the same current. So each battery in a series chain can sit at a different voltage. The sum of the voltages is all the charger will see. So one battery could be flat and the other overcharged but the total would look fine (up to a point). Batteries in series do eventually go slightly out of balance (due to different capacities and self discharge) but this is usually a long term process. Putting unbalanced loads on each battery aggravates the imbalance. A very tiny load on each battery just takes a lot longer before the imbalance becomes apparent.

Flooded lead acid cells typically tolerance a bit of imbalance as they shed the excess energy via heat and gassing. You lose some electrolyte which can be replaced. However this you cannot do that with sealed/maintenance free lead acid or with lithium. Out of interest, some BMS systems for lithium actually "balance" the cells with a special circuit that measures each cell individually and pulls them back into balance by either dumping or redistributing some of the energy.
thank you for this
i am only running 2 low current things here so i am going to rather get a 24v->12v Dc/DC converter and just run them all off that instead of 1 device per battery as i am doing now.

you learn something new everyday :thumbsup: :thumbsup:
 

Papa Smurf

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Aug 2, 2016
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20,409
this should do the trick

fibre box power supply is rated at 500mA and wifi router power supply is rated at 1500mA
this then leaves me with 1A for LED strip lighting which is around 5metres but i will never go that length, 50cm max here in the lounge
 
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