vielle568
Member
I have installed a hybrid system consisting of a wind generator and some solar panels to provide energy for my house. The energy is used to charge a bank of twenty 150AH lead acid deep cycle batteries that are connected in series. The batteries have a charge controller with a dump load to ensure that they are not "overcharged" when there is too much wind; there is also a relay to automatically reconnect the house to the electricity company should the battery level get too low. An inverter changes the DC voltage from the batteries and converts it to AC for the house.
Sadly the system does not work correctly; when the batteries are charged up (around 260 volts) and the house is connected it will only have enough energy to run for a couple of hours before the voltage level has dropped to below 250 volts and the system is ready to disconnect. When it was initially set up the batteries would support the house for at least four days without any wind blowing! There's a leak in the system somewhere and I don't know how to track it down.
The batteries seem to charge OK, but slowly. I get the impression that if the charge level drops then the battery voltage actually starts to drop slowly. There's power coming in from both the generator and PV panel cables so the batteries are getting their charge voltage alright.
I've checked all the batteries too. Every one is reading 12,XX volts so I can't see any indication of a burnt out cell causing the problem.
The inverter works OK and is not drawing an excessive load; I measured the current flowing in the cable when the inverter had no output and it was taking about 0,8A (it's a 5KW inverter).
I am getting suspicious about the cables. There are 20 jumper cables connecting the batteries in series; I made these up myself; could these be causing the leak in the system? The cable lugs are bolted to the battery terminals but the cables are soldered to the lugs. Could a poor joint be the cause of such a problem? If so, how can I check out the cables? Any other ideas?
I've included a simple sketch of the system diagram. Thanks for any advice on this subject.
Sadly the system does not work correctly; when the batteries are charged up (around 260 volts) and the house is connected it will only have enough energy to run for a couple of hours before the voltage level has dropped to below 250 volts and the system is ready to disconnect. When it was initially set up the batteries would support the house for at least four days without any wind blowing! There's a leak in the system somewhere and I don't know how to track it down.
The batteries seem to charge OK, but slowly. I get the impression that if the charge level drops then the battery voltage actually starts to drop slowly. There's power coming in from both the generator and PV panel cables so the batteries are getting their charge voltage alright.
I've checked all the batteries too. Every one is reading 12,XX volts so I can't see any indication of a burnt out cell causing the problem.
The inverter works OK and is not drawing an excessive load; I measured the current flowing in the cable when the inverter had no output and it was taking about 0,8A (it's a 5KW inverter).
I am getting suspicious about the cables. There are 20 jumper cables connecting the batteries in series; I made these up myself; could these be causing the leak in the system? The cable lugs are bolted to the battery terminals but the cables are soldered to the lugs. Could a poor joint be the cause of such a problem? If so, how can I check out the cables? Any other ideas?
I've included a simple sketch of the system diagram. Thanks for any advice on this subject.