Dumpload controller is dumping before batteries are full

[Glemmon]

I have a 10 ft otherpower 24 volt turbine, I have 2 12 volt marine batteries (not ideal, I know) And I have a ghurd dumpload controller. When the turbine hits 28 volts the controller starts dumping before the batteries are charged and it drops the rpm on the turbine at this point and I'm not seeing any amps because it draws from the turbine. I'm quite sure the controller was built correctly. My dad put it together for me and he was an electronics technician at AMI for 30 years. I'm wondering if I have it hooked up wrong, or if the batteries are shot and won't take the charge. The dumpload is hooked directly to the batteries and so is the controller. I have it hooked up like the drawing I found on this site by Steven Fahey created 1-15-2008. http://www.otherpower.com/images/scimages/4378/Connection_2008Jan_sm.gif. Is this enough info? I don't know nearly enough to figure this out. Your help will be greatly appreciated.

[zap]

When the turbine hits 28 volts the controller starts dumping...

It sounds like it's working exactly as it should.

before the batteries are charged

What makes you think the batteries are not charged?  Right around 28v is where it should start dumping power and your batteries should sit at 28v as long as you're dumping power.
If the battery voltage drops off quickly once off charge then something else is wrong.


I'm not sure about the picture you linked.  Ghurd's picture from his site is as simple as it gets.

[Glemmon]

I have a meter hooked up to the batteries. It shows 14 volts. The batteries are shot, they take a charge but don't hold it for long. I'm only using them for a load on the alternator until I can get good ones, because I like to watch it spin. Maybe they are at the point they no longer take a charge so all the power goes directly to the dumpload?

[wooferhound]

Sounds like its working perfectly, you don't want it to dump lead acid batteries much more than 28 volts. As soon as the batteries are Full (28vdc) it will stop sending the overcharging voltage to the batteries and then start sending it to the dump load so it will not damage (overcharge) them. You said you are reading 14 volts, so what exactly is the problem?

[Glemmon]

Thanks for the input. The problem is both batteries in series read 14 volts they should read 28. So I guess one battery is completely shot. it won't take the charge so the dumpload takes over at 28 volt input. I thought the dumpload didn't come on until the batteries reached 28 volts, not when the alternator reached 28 volts. If the mill isn't able to spin over the rpms needed for 28 volts, due to the resistance of the dumpload, how is it able to produce the amps needed to charge the batteries. There must be something I'm not understanding.

[RP]

I suspect a problem in the hookup.  Can you make us a drawing of how everything is connected?  In particular we need to see the connections between the rectifiers, batteries and dumpload controller.

[zap]

I thought the dumpload didn't come on until the batteries reached 28 volts, not when the alternator reached 28 volts.

The system should be wired alternator to batteries, batteries to controller.  Basically, since they're all hooked up together they will all be at the same voltage... minus any voltage drops in the wire connecting them.