Battery question

[Larry Morgan]

I have an NX750 with a 90hp motor. I installed LED lights on the deck and compartments (even the cup holders, lol) and also a new stereo with 4 speakers along with a subwoofer. Everything works great but I am concerned about battery drain when we are just floating about and swimming. Everything runs off of the motor battery and with all the extra stuff I've added to it (amp and sub most noteable) I was thinking of installing a second battery in parallel with the motor battery. My question is will this overload what the motor is capable of charging? It will still be 12 volts but I'm unsure if the added capacity will draw too many amps when charging.



Maybe a safer bet would be to install a "backup" battery and a battery switch to use in case the battery ever gets too low to start the engine? I keep a very close eye on voltage when I'm not running the engine and have run everything a couple of hours without charging and it was fine. I like to think ahead and be prepared though.

Thank you in advance for any input

 

[byron cooley]

Or a light set of jumper cables to jump to the TM battery if needed

 

[FLsportsman]

I have two cranking batteries with a battery switch/selector on our family boat. Just to be safe. Perko make them. So

 

[Gene B]

I carry an old set of jumper cables that I shortened in the boat all the time. I had a battery that was getting weak but still worked fine unless I was on the water all day. It was a cheap way to keep from having to buy a battery at the time. It has saved me a couple times. I also had an issue with my 3 way cord that I plug my single bank(cranking)and 2 bank(trolling) chargers into. One of the outlets on the cord wasn't making good contact and didn't charge the starting battery. After a couple hours running the depth finders, the big motor wouldn't start. I popped the lid and connected the jumper cables and I was on my way!



Gene

 

[TOMMY RICH]

Can't beat jumper cables

 

[mike daniels]

I took everything off the motor battery and ran it to the troll motor battery.



no more worries.



My TM battery is a deep cycle so it doesn't mind getting discharged. The cranking battery claims to be a "marine" battery but I've seen the lead plates and the real deep cycle batteries have thicker places. Thin plates give you cranking amps but they don't like to be discharged and recharged much. Thick plates won't give you cranking amps but can tolerate charging cycles.

 

[Larry Morgan]

Thanks for the suggestions, I've yet to install an onboard charger but it's going to be the next purchase which is why I'm deciding on batteries now. I like the idea of off loading the electronics to a deep cycle battery. I think I'll mix it up a bit. I know I'm installing a second battery for my TM and I think I'll install another deep cycle to run the electronics but with a battery switch so if I manage to run the battery down I can still use the motor battery as a backup for the electronics. So, yes Doug I think I will have 4 batteries on board. I do have jumper cables on board just in case, I always carry a set. I just like my projects to look/perform professional. (took me a month to decide on stereo/speaker arrangment lol)