how much extra DC do I have???

[Jegomes]

I have a 1975 merc 1500 TB and I was wondering how much electricity I have to spare while underway. It seems to charge the battery very fast. I have almost no draw on it as there are no accessories that run. I really just want to know if I can safely run a radio and maybe even a small amp

thanks for any input

 

[Chris1956]

Re: how much extra DC do I have???

You have about 9A (100 Watts) of power avail at near full throttle, provided your stator and rectifier are good. As long as the radio and amp take modest power (<5A), or you do not listen to it all day with the motor off, you will not have an issue.

 

[Mr_Shamrock]

Re: how much extra DC do I have???

I have a pretty substantial stereo system - 8 - 6 1/2's and 1 - 12" subwoofer with a 400 watt amp. I have dual batteries and a battery switch. One of my batteries is strictly for accessories and the other is the starter battery. When underway I can have the stereo cranked all day if I wanted. I can beach the boat and the one battery will run the stereo at a decent level for about 5-6 hours (depending on the volume level). My batteries are on their 4th season and I will be replacing them before next season. This is an area where you get what you pay for and a good high quality battery is well worth the piece of mind!