Test the voltage put out by your charging system using a volt ohm meter. Then check the specs on the FF. My Elite 4 CHIRP will handle up to 17 VDC.
I have an older motor that uses a rectifier for charging instead of a voltage regulator. I would like to wire my graph, an Elite 7 HDI, directly to my cranking battery, but I'm worried that over voltage from the rectifier could damage the unit.
Is this a valid concern? Thanks.
Test the voltage put out by your charging system using a volt ohm meter. Then check the specs on the FF. My Elite 4 CHIRP will handle up to 17 VDC.
Most DFs will handle up to 17 volts as Sovran stated. I doubt your charger would run more than maybe 14 or 15 volts but I would double check. I think you will be fine, but check first. Don't want to fry the Chirp.
Mark 1:17 ...I will make you fishers of men
Thanks for the replies, guys. The voltmeter on my instrument panel tops out at 16 volts. It is usually pegged at WOT. I Have not checked it against another meter for accuracy. I'll hook it up to a digital meter the next time I'm out.
That is very common with an unregulated system. Most modern electronics will shut down when it senses over charging. Some things you can do to help prevent over charging is make sure all cables are squeaky clean and tight. Always use a marine battery and never a car battery. There is a big difference. And you can always get rid of the rectifier and install a universal regulator/rectifier.
Fair Winds and Following Seas
Bill H. PTC USN Ret
Chesapeake, Va
Thanks BB- I'm using a lead acid marine starting battery. The leads are on "farmer tight" with lock nuts. I already have a power lead run to the bilge and have been running the graph off of my second TM battery. I've been running two TM batteries in series, but no longer need to since I resolved a power drain in my TM wiring. Would like to eliminate one of the batteries to help balance the boat better.