Batteries

[Dellis]

I know this has been discussed before on the forum, I'm chasing the specs on the odeesy type battery or similar, that is suited to starting a EA 81, prerotating 29 foot blades and keeping all the electrical things running. Being situated in Gove , where can I by one? Dave Ellis

[asra]

I am not sure the actual specs Dave but I have had two and can recommend them though the price is steep. One point to think about is that no battery likes massive discharge and I ruined my first battery that way by starting and pre-rotating each time even for short flights. That battery only lasted 12 months and at a cost of about $250 it was an expensive lesson. I replaced it with another Odessy same type and this time I sometimes prop start, always hand start the rotors before prerotating, and keep the battery on a solar cell when not in use. It is 5 years old now and going beautifully. Cycling the battery often and topping up with a solar cell seems to have done the trick. Incidentally, I have a 9 year old motorcycle that I bought new and it has its lights permanently on when the ignition is on, and the battery has not failed me yet. Cycling the batterys seems to do the trick. Hope that helps.PeteBairnsdale,Vic.

[asra]

I am not sure the actual specs Dave but I have had two and can recommend them though the price is steep. One point to think about is that no battery likes massive discharge and I ruined my first battery that way by starting and pre-rotating each time even for short flights. That battery only lasted 12 months and at a cost of about $250 it was an expensive lesson. I replaced it with another Odessy same type and this time I sometimes prop start, always hand start the rotors before prerotating, and keep the battery on a solar cell when not in use. It is 5 years old now and going beautifully. Cycling the battery often and topping up with a solar cell seems to have done the trick. Incidentally, I have a 9 year old motorcycle that I bought new and it has its lights permanently on when the ignition is on, and the battery has not failed me yet. Cycling the batterys seems to do the trick. Hope that helps.PeteBairnsdale,Vic.

[Dellis]

Thanks Pete, HHHmmm $250 each hey , yep I'll put the second morgage on the dog again .Have you a number off the battery of the specific one that you use so I can ring and order on on up , as long as tommorrow I've still got a gyro left , given the cyclone is just running past us as I speak ,we are 100km from the 40 km across eye, and if I was named Bill , I'd be very happy about now .Unfortunatly , it's getting fairly interesting , it's started to get serious from 1500, Ihope the hanger the machine is in lives through the night .Dave ellis

[Dellis]

Thanks Pete, HHHmmm $250 each hey , yep I'll put the second morgage on the dog again .Have you a number off the battery of the specific one that you use so I can ring and order on on up , as long as tommorrow I've still got a gyro left , given the cyclone is just running past us as I speak ,we are 100km from the 40 km across eye, and if I was named Bill , I'd be very happy about now .Unfortunatly , it's getting fairly interesting , it's started to get serious from 1500, Ihope the hanger the machine is in lives through the night .Dave ellis

[Brian]

Hi Dave, the one I bought last October was a PC 625 . Thats a diferent number but same battery as the one before but I reckon the old battery was a 700 !Valuable dog there Dave Hang in there Dave !!!BrianPooncarie NSW

[Brian]

Hi Dave, the one I bought last October was a PC 625 . Thats a diferent number but same battery as the one before but I reckon the old battery was a 700 !Valuable dog there Dave Hang in there Dave !!!BrianPooncarie NSW

[Scott Hogan]

You can get the specs of the Odyssey batts here,http://www.aeroparts.com.au/odyssey.htm[]Hoges

[Scott Hogan]

You can get the specs of the Odyssey batts here,http://www.aeroparts.com.au/odyssey.htm[]Hoges

[asra]

Pete and Scott,The "Odyssey" name is the TM for the Hawker group of USA, and like most of the small high powered batteries will give a heavy discharge rate as they have a lower internal resistance, (like a cranking battery) however they don't like the sudden heavy recharge rate, when I was working for Telstra we found that all of our UPS's were failing through battery failure when they were most needed, I queried Hawker on the charge rate and they told me the recharge rate was 12%, (this was the recharge rate we had them set at) and we continued to have the same failure rate, I finaly got hold of a professor at a Queensland University who had done a indepth study of this type of battery and his exact words were................"my son, do not listen to the "salesmen" if you have the recharge rate higher than four or four and a half percent you will "bugger" them every time".I followed this advise and and had them all current limited down to a 4% recharge rate, and from that day onwards the problem ceased.At this point in time there is another generation of better, far cheaper and more "Grunty" batteries available, particulary for the heavy current requirements of the Rotax 912 and 914 series that have a high compression ratio, and also for the heavy drain of the pre-rotator starter motors, for example, the Robert Bosch BXH-137 six pole permanent magnet planetary drive motor can draw 210amps and the pull in solinoid 32amps, at a nominal voltage of twelve volts this equates to 2904 watts, or to bring this into some sort of easy understanding it is almost equivelent to turning on the household three bar radiator, all the best.Pete Barsden

[asra]

Pete and Scott,The "Odyssey" name is the TM for the Hawker group of USA, and like most of the small high powered batteries will give a heavy discharge rate as they have a lower internal resistance, (like a cranking battery) however they don't like the sudden heavy recharge rate, when I was working for Telstra we found that all of our UPS's were failing through battery failure when they were most needed, I queried Hawker on the charge rate and they told me the recharge rate was 12%, (this was the recharge rate we had them set at) and we continued to have the same failure rate, I finaly got hold of a professor at a Queensland University who had done a indepth study of this type of battery and his exact words were................"my son, do not listen to the "salesmen" if you have the recharge rate higher than four or four and a half percent you will "bugger" them every time".I followed this advise and and had them all current limited down to a 4% recharge rate, and from that day onwards the problem ceased.At this point in time there is another generation of better, far cheaper and more "Grunty" batteries available, particulary for the heavy current requirements of the Rotax 912 and 914 series that have a high compression ratio, and also for the heavy drain of the pre-rotator starter motors, for example, the Robert Bosch BXH-137 six pole permanent magnet planetary drive motor can draw 210amps and the pull in solinoid 32amps, at a nominal voltage of twelve volts this equates to 2904 watts, or to bring this into some sort of easy understanding it is almost equivelent to turning on the household three bar radiator, all the best.Pete Barsden

[Brian]

Tell us more Pete, whats the name of the "grunty" batteries you reffer to ???BrianPooncarie NSW

[Brian]

Tell us more Pete, whats the name of the "grunty" batteries you reffer to ???BrianPooncarie NSW

[asra]

Thanks Pete. Your experience is identical to my own with these batteries and of course the continual trickle charge of the solar cell has provided the very low recharge rate necessary to sustain the life in the battery. I too would be interested in details of the new age batteries you speak of.PeteBairnsdale,Vic.

[asra]

Thanks Pete. Your experience is identical to my own with these batteries and of course the continual trickle charge of the solar cell has provided the very low recharge rate necessary to sustain the life in the battery. I too would be interested in details of the new age batteries you speak of.PeteBairnsdale,Vic.