Charging Capacity Question

[pjmsj21]

Excuse my lack of basic electrical knowledge but I am trying to determine if I need to purchase a battery charger pack for my I-Phone 8 Plus while taking our boat on a San Juan week long cruise.

I sail a Catalina 27, with a Yamaha 9.9 with the alternator and a new 12 volt battery with 85 amp hour capacity. The Yamaha has an electric starter along with a manual cord starter in the event that I need it.

I anticipate adding a 12volt to USB charging cord to keep my phone charged during the week. Additional uses will be depth and knotmeter, and interior lights. I have charts but would like to use the Navionics on my phone as much as possible.

Should I purchase an battery pack dedicated to my phone or should I have enough capacity with a moderate amount of motoring?

Thanks!

[rgleason]

I think you will be fine with the 85ah battery and the Yamaha alternator (how many amps is the output?) provided:
1. The battery is fully charged (what type of battery?)
2. You monitor its voltage, not letting it get below 12.2 or 12.3volts if it is lead acid.
3. You run the engine to charge the battery when needed.
4. Or you get a small solar panel with a controller to top off the battery when the sun is out. (but you might not even need that as your loads are small.


Try making a list of the amps used by each device and the hours you expect to be using it in a day and post it here please

[GrowleyMonster]

You would probably like OpenCPN on an Android better than Navionics on an I-thing. Just sayin. But maybe get one of those jump starter things for a backup power source for your phone. Since you are using it for navigation, you really should have redundancy in your power source(s). A solar panel would be nice to help keep your battery topped up, too. You could mount it on your pushpit rail, hanging out over the stern.

[rgleason]

I second Growley's suggestion to use OpenCPN,
but you'd need android, raspberry pi, mac, or windows.

[rgleason]

Also try to get a simplse portable 10 amp 3 step like a Guest, so that you can charge more completely when at a marina or have shore power 120vac.

[pjmsj21]

I have one of these coming to charge my phones (https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1) along with the USB-C charging cord.

I do have a shore power cord that I carry and will be spending a few nights in marinas. At this point I think that I may be fine without adding a battery pack for the phone/GPS.