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MattieG
Starting Member
United Kingdom
37 Posts |
 Posted - 15/08/2008 : 03:23:22
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Hi
Ive had to convert from 12V battery bank to 24V battery bank lately and was wonderring if I can connect two 12V 300W inverters (same model in series to the 24V bank instead of buying a new 24V inverter?
Might be quite interesting???? Any ideas anyone.
Mattie
Mattie
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optixelectrics
Junior Member
United Kingdom
102 Posts |
Posted - 15/08/2008 : 14:04:02
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Mattie,
You can connect one inverter to each 12V battery, however, there is a catch! you must put the same amount of load on both inverters otherwise one battery could be more discharged than the other. The problem then comes that if one battery is at 11V, and the other at 13V (remember that 13.8V is charged for a 12V cell), then you have 24V across the cells. If you then charge those cells to the joint max voltage (28V), then the one with 13V will have a voltage of 15V, and the 11V battery will have a voltage of 13V. So, one battery is overcharged, and the other isnt quite charged, hence why you need to balance the discharge. You can get a voltage dropper to go from 24 to 12V. If you look at some Truck websites (or maybe Ebay), they have them on there for running 12V appliances (CB, TV, Fridge etc). This may be your cheapest option.
Myk
Goto www.optixelectrics.co.uk and click on 'renewable' for Dump Load Controllers, Turbine and battery monitor units. Grid tie installations. Custom projects catered for. |
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MattieG
Starting Member
United Kingdom
37 Posts |
Posted - 15/08/2008 : 16:34:39
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Hi
I dont think I can connect them to the batteries as they are connected together and give 24V which even connections you use. I was more thinking of connecting the inverters together (positive to negative on each) ten connecting the positive of one inverter to the + of the battery bank and the negative of the other inverter to the negative of the battery bank. I think that may work althoug if i turn one inverter off it would go bang i think :(
Mattie
Mattie |
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Roadkill
Starting Member
USA
13 Posts |
Posted - 15/08/2008 : 19:01:55
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quote:
Originally posted by MattieG
I was more thinking of connecting the inverters together (positive to negative on each) ten connecting the positive of one inverter to the + of the battery bank and the negative of the other inverter to the negative of the battery bank. I think that may work althoug if i turn one inverter off it would go bang i think :(
You'd best get yourself a bag of marshmellows first to roast over the resultant fire. Could you also please video this for us - should be quite a show! Seriously, don't do it! |
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XexorZ
Starting Member
36 Posts |
Posted - 15/08/2008 : 20:42:03
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DO NOT attach these two devices in series and expect anything except two destroyed devices and a battery fire.
The solution is to use a single 24V inverter.
Using single inverters on each battery would also work but would unbalance the batteries (another bad thing).
Sorry :( |
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MattieG
Starting Member
United Kingdom
37 Posts |
Posted - 15/08/2008 : 23:16:31
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No probs I will get myself a single 24V inverter.
I cant see how a 12V inverter can connect to one of the batteries in a bank surely that one battery would still show 24V... hmmm interesting if it didnt though :)
Mattie
Mattie |
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XexorZ
Starting Member
36 Posts |
Posted - 16/08/2008 : 02:48:52
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Mattie,
You are making the right and SAFE choice here... but purely for information:
two batteries connected in series have voltages relative to each other.
in other words, picture the positive terminal of battery A as 12+ Volts with respect to the Negative terminal of battery A... So, when we connect Battery A's positive terminal to battery B's Negative terminal, Battery B's Positive terminal is 24 volts with respect to battery A's Negative terminal...
Battery A's positive is STILL 12 V with respect to its own Negative
Battery B's positive is STILL 12 V with respect to ITS own Negative...
The PROBLEM with using a battery that is part of a series bank of batteries as a single battery (i.e. 1 12 volt battery of a 2 battery 24 volt bank) is that you deplete that battery INDIVIDUALLY as opposed to depleting the entire bank. This causes an imbalance in the bank of batteries (i.e. Battery A is 1/2 full, Battery B is fully charged). THIS is bad :)
I hope this helps and does not hurt.
To Recap: Mattie is still buying a 24Volt inverter so he does not melt down, self destruct, and kill all of his house hold pets :)
-George
My Website: www.GoingGreenGrapevine.com |
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MattieG
Starting Member
United Kingdom
37 Posts |
Posted - 16/08/2008 : 09:24:15
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Lol... 24V inverter ordered :)
Ah... that is interesting to know. Electronics was never my strong point at college!!!
On a good note I have found some sprockets and chains (cheap aswell) for gearing up my Ametek 38V so I will let you all know how that goes :) ... I cant wait.
Mattie
Mattie |
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Topic |
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Two 12V Inverters off 24V Batteries?
