wingnut771

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Thanks but PSW would be on overkill for my router, TV + 2 lights
Was thinking more along the lines of what if in future your power goes out for 3 days, you would have something to power the fridge but on second thought 12V might be a bit small.
 
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MrR030TZA

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Aug 9, 2018
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Hi There,

Need help, I have a Mecer 2400VA Inverter and 2 x 105 ah Battery connected in Series and have electronics connected that add up to 300W. I am currently only getting 50 mins until it starts beeping. Bear in mind that both batteries are new.

I am wondering if the batteries are not balanced or is it perhaps that the inverter is faulty, also even after inverter beeps and then cuts power completely (meaning no more battery power left) and Eskom power comes back on, its set to 10 amp charge but only charged for an 1h30 mins and then stopped charging...well fan stopped the LED stopped flashing.

Please can you let me know what could be the issue here and what can I do to perhaps fix it, also how much should I be able to get with 2 x 105ah and using 300W if batteries fully charged?
 

Lupus

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Apr 25, 2006
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38,670
Hi There,

Need help, I have a Mecer 2400VA Inverter and 2 x 105 ah Battery connected in Series and have electronics connected that add up to 300W. I am currently only getting 50 mins until it starts beeping. Bear in mind that both batteries are new.

I am wondering if the batteries are not balanced or is it perhaps that the inverter is faulty, also even after inverter beeps and then cuts power completely (meaning no more battery power left) and Eskom power comes back on, its set to 10 amp charge but only charged for an 1h30 mins and then stopped charging...well fan stopped the LED stopped flashing.

Please can you let me know what could be the issue here and what can I do to perhaps fix it, also how much should I be able to get with 2 x 105ah and using 300W if batteries fully charged?
Roughly 3 to 4 hours at 300w
 

wingnut771

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Joined
Feb 15, 2011
Messages
15,062
Hi There,

Need help, I have a Mecer 2400VA Inverter and 2 x 105 ah Battery connected in Series and have electronics connected that add up to 300W. I am currently only getting 50 mins until it starts beeping. Bear in mind that both batteries are new.

I am wondering if the batteries are not balanced or is it perhaps that the inverter is faulty, also even after inverter beeps and then cuts power completely (meaning no more battery power left) and Eskom power comes back on, its set to 10 amp charge but only charged for an 1h30 mins and then stopped charging...well fan stopped the LED stopped flashing.

Please can you let me know what could be the issue here and what can I do to perhaps fix it, also how much should I be able to get with 2 x 105ah and using 300W if batteries fully charged?
1634063417354.png 1634063532713.png
You should get just over 2 hours down to 50% DOD.

Your batteries are either DOA, or unbalanced. Disconnect them, make sure they are the same voltage then parallel them for 24 hours, then connect back in series and try again. If still a problem then send them back.

EDIT: Hope you don't have string as cable like that other guy - can you take a pic?
 

MrR030TZA

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Messages
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View attachment 1165740 View attachment 1165742
You should get just over 2 hours down to 50% DOD.

Your batteries are either DOA, or unbalanced. Disconnect them, make sure they are the same voltage then parallel them for 24 hours, then connect back in series and try again. If still a problem then send them back.

EDIT: Hope you don't have string as cable like that other guy - can you take a pic?
Hi, if you talking about how the batteries are connected up here is two pics attached.
 

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MrR030TZA

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Nope, made sure all tightly connected. I will measure the batteries tomorrow and get back to you.
I have another question in the meantime, whats considered better, running 2 x 105ah batteries in parallel or series? I know the difference is either in parallel you get double the battery capacity and in series you get double the voltage, in what scenario is one better than the other?
 

wingnut771

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I have another question in the meantime, whats considered better, running 2 x 105ah batteries in parallel or series? I know the difference is either in parallel you get double the battery capacity and in series you get double the voltage, in what scenario is one better than the other?
imho, 12V parallel is better because the load/work is shared between the 2 batteries whereas with series, one bad cell (a battery has 6 cells in series) will bring whole bank down like in your case on 24V. Series is only as strong as it's weakest link. CON of 12V is more amps (300W/12=25A vs 300W/24=12.5A) so need thicker cables which is more $$$.

Both cases give you same Wh so it's much of a muchness when it's all working properly.

12V x 200Ah = 2400Wh
24V x 100Ah = 2400Wh

Can someone check my work.
 

TheChamp

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Feb 26, 2011
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imho, 12V parallel is better because the load/work is shared between the 2 batteries whereas with series, one bad cell (a battery has 6 cells in series) will bring whole bank down like in your case on 24V. Series is only as strong as it's weakest link. CON of 12V is more amps (300W/12=25A vs 300W/24=12.5A) so need thicker cables which is more $$$.

Both cases give you same Wh so it's much of a muchness when it's all working properly.

12V x 200Ah = 2400Wh
24V x 100Ah = 2400Wh

Can someone check my work.
That's about it really, I have noticed that most people here run loads of not more than 500W so I don't see the point of the 24V system. Batteries are just too expensive to have to worry about buying two when you need them.
 

MrR030TZA

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imho, 12V parallel is better because the load/work is shared between the 2 batteries whereas with series, one bad cell (a battery has 6 cells in series) will bring whole bank down like in your case on 24V. Series is only as strong as it's weakest link. CON of 12V is more amps (300W/12=25A vs 300W/24=12.5A) so need thicker cables which is more $$$.

Both cases give you same Wh so it's much of a muchness when it's all working properly.

12V x 200Ah = 2400Wh
24V x 100Ah = 2400Wh

Can someone check my work.
Ok thank you for that information, when you say thicker cables do you think my cables your saw in the pics Okay to run in Parallel and am I able to use the Mecer 2400VA with 2 x Batteries in Parallel?
 

wingnut771

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Ok thank you for that information, when you say thicker cables do you think my cables your saw in the pics Okay to run in Parallel and am I able to use the Mecer 2400VA with 2 x Batteries in Parallel?
No, 2 batteries in parallel is 12V. You have a 24V inverter. You will break something like the other poster having rotten egg smell a few pages back.

You would need this:

Also, you would need extra cables to wire it up parallel, so new appropriately sized cables too. There is a method in connecting them properly I just can't find it, (method 3?) maybe if someone can post the link?
 

MrR030TZA

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No, 2 batteries in parallel is 12V. You have a 24V inverter. You will break something like the other poster having rotten egg smell a few pages back.

You would need this:

Also, you would need extra cables to wire it up parallel, so new appropriately sized cables too. There is a method in connecting them properly I just can't find it, (method 3?) maybe if someone can post the link?
Ok thanks, I actually do have a 1200VA 720W inverter so thats a bonus but what is the max watts you would recommend running on a 720W?
 

wingnut771

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Ok thanks, I actually do have a 1200VA 720W inverter so thats a bonus but what is the max watts you would recommend running on a 720W?
It's not so much how many watts is recommended but rather how much capacity you have for how long. If you had a load of 700W, this is how much battery you would need if you wanted to run for 2 hours, using this calculator https://www.jcalc.net/battery-size-calculator
1634073786941.png
You would need 4 x 100Ah batteries, that's why people try and be as economical with the load as possible because batteries are expensive.
 

Mandarb

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Sep 20, 2007
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Did the Hubble batteries not fit inside the trolley? Thought they were same form factor as the LA/AGM batteries?
Yeah, about 4cm too long at a guess. You could put the batteries in, but it will overhang and you won't be able to put the cover back on. Geewiz did warn me about that.

It took a while for the inverter to show 100%, and fan is still a bit noisy. Green light is still flashing, which I think means it's charging? If so that's more than 12 hours now. Will leave it for today and see if it gets there before worrying.
 

Mista_Mobsta

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That's about it really, I have noticed that most people here run loads of not more than 500W so I don't see the point of the 24V system. Batteries are just too expensive to have to worry about buying two when you need them.
The 24V unit does help when your wife decides to plug the vacuum cleaner into a socket that's connected to the inverter - especially when she doesn't bother to read the bloody label on the socket itself :)
 

Mista_Mobsta

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As a quick Q -> does anyone know at which voltage differential 2 AGM need to be balanced? My 2 AGM batteries show a difference of 0.10-0.15V between them at all times, even during charging and use. The difference has been the same for around 9months now and wondering whether that will cause issues going forward?
 
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