View Full Version : Dont Know What Is Not Working Or Where To Start
June 25th, 2008, 10:02 PDT
Hi all, I am hoping you can help, I have a 1600watt pure sine wave inverter, if i plug in anything over around 300 watts into my house it all trips off, whats going wrong any suggestions. for info i have 6 x 2volt batteries 765amp, i have a charge controller and a victron multi inverter, any suggestions would be appreciated
June 25th, 2008, 10:15 PDT
It sounds like a low voltage disconnect situation. 300 watts is ~25 amp/12vdc, a pretty good draw on the battery. Are you batteries full charged? and how do you know?
1600 watts is ~133 amp load. That is asking the battery to produce ~15% of it's capacity instantly. I suspect you have too big a draw relative to the size of the battery. I also would suspect undercharged batteries.
June 25th, 2008, 10:40 PDT
Especially if the load you are running surges when starting.
June 25th, 2008, 11:19 PDT
Hi the batteries are fully charged according to the charge controller, it says soc 99% i can run the tv, computer, various lights and radios, during the day once the fridge has had a boost from mains it can run all day on it aswell. However if i turn all of this off and try the water pump which is 375 watts it knocks the inverter off, this particular pump is to draw water from the well, i can use a pump that is 400 watts on the system that empties a cellar! which seems bizarre to me. my neighbour had a 1500 watt inverter and his works fine with a slightly larger pump. When i first installed the system we could operate things like the toaster etc but now it knocks of in less than ten seconds. I had one terminal that was black on the connection to the battery but we changed the o rings and bolt, apart from that i dont know what else can be wrong.
June 25th, 2008, 11:32 PDT
Check the starting load on the pump. Many (most?) starting loads are very much bigger then their running loads, sometimes as much as 10 times. Your sump pump isn't designed to lift against pressure so it's starting load will be less.
Check the starting load with a kill-a-watt or an ammeter to see what it is really drawing. Perhaps you can wire a pressure relief so that it can start against a lower pressure.
PS. On further reading of your post, I have another comment. Just because the monitor says the battery is 99% doesn't mean much without some other information. It is revealing that you can run fewer loads now than you used to be able to. That tells me that your batteries are either getting tired and they can't hold a charge, or perhaps you have a bad cell, or poor connections between cells. Test each cell with a hydrometer to check their Specific gravity. I have a suspicion that you may have been chronically over drawing/undercharging because of a bad cell. You meter says 99%, but if it is like mine, it only calculates what goes in vs what goes out. It doesn't really measure capacity. While it is useful, it is most useful day to day and not to test battery condition over time.
Keep us posted.
June 25th, 2008, 11:35 PDT
ok will have a look at that, what do you think are the maximum watts i should get out of it, and any idea why something like the toaster would work before but wont now?
June 25th, 2008, 11:49 PDT
What model is the charge controller and what is telling you 99% charge?
I'll hazzard a guess its a BZ-500 ...
You need to check you battery voltages, everything points to weak batterys. What is keeping the battery's charged?
June 25th, 2008, 11:53 PDT
Heavy loads that used to work, but don't work now... You need to look at your electrical connections (check with a volt meter, the voltage drop between each connection and the actual voltage at the input of your inverter). Also, check the AC voltage (under load) at each of your major points of use (could also have bad connections elsewhere too).
Also, a charge controller cannot really tell the state of charge of a battery very accurately. If these are flooded cell batteries, check the water levels and electrolyte specific gravity (temperature corrected).
Also, check the voltage of each cell, while charging and under load. If one or more cells are more than a hand full of millivolts different from their neighbors, then you may have a cell going bad.
It is pretty easy to over or undercharge (or over draw) a battery bank. A battery monitor (http://store.solar-electric.com/metersmonitors.html) is probably the ideal tool for monitoring the overall state of charge of your battery bank.
And, if you have not before, read the Wind-Sun / NAWS battery faq (http://www.windsun.com/Batteries/Battery_FAQ.htm)--it will help you to understand how everything plays together.
Powered by vBulletin® Version 4.1.10 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.