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Unread 08-05-05, 11:13 PM
Ernie Martin's Avatar
Ernie Martin Ernie Martin is offline
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Join Date: Apr 2002
Location: Miami, Florida
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I wonder if Pete Somers can expand a bit on jumping across the battery, rather than through the external power socket. The way I read it, you're suggesting doing it as in a car, where you use a pair of jumper cables to go from one 24V external battery (or two 12V batteries in series, for people like me in-out islands where there are no 24V batteries) directly to the posts of the aircraft's battery. In Paul's case, would a desirable prior step might have been to check water level in the cells and add distilled water first?

The way I read this, if you do it Pete's way, and keep the external battery on for a few moments after both engines have started, both alternators will start because they are seeing a healthy 24V (from the external battery). I assume that the real value of this procedure is when you have a totally dead battery (if you have a battery which is too weak to start the engines but still has some juice in it, I think the alternators will start, right?)

We would be grateful, Pete, for your comments and suggested procedure. For instance, do you remove the jumper cables and external battery, and replace the battery cover and front-engine cowlings with the front engine running? Or -- for safety -- do you shut off the front engine and, with the rear engine running to charge the battery, clean up the front-engine area? My concern with the safer approach, for a totally dead battery like Pauls', is that the 10-15 minutes of charging with the rear alternator may not put enough energy into the battery to start the front engine.

Thanks in advance for your views.

Ernie
(Hadn't lost interest in Skymasters, just been away for two months)
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