F70 Min Voltage to Start?

[Lumpo414]

I have a 2017 F70 and i want to set my voltage alarm on my hummingbird. Anyone know the minimum voltage that's needed to start a F70 or recommend how low i should set the alarm? Thanks

[99yam40]

you need 2 batteries one to start and run the motor, and another house battery to run everything else.

if a battery gets drained enough for voltage to drop, there is a very good chance it will not furnish enough amps to start

[Lumpo414]

I have one battery to start my motor and run my Hummingbird Helix 7 and a second battery in front to run the t r olling motor. I upgraded my starting battery because every time I started my motor it would shut my hummingbird off. My battery now has double the CCA and reserve now i just want to set low voltage alarm but unsure where to set it.

[boscoe99]

12.2 volts would represent a battery at approximately 50% state of charge. Which I believe to be more than enough to crank and start your F70. That is where I would set your low voltage warning. Of course you might want to test your specific set up to see if 50% will get the job done.

[Lumpo414]

My choices are 12.5 and 12 so I have it set to 12.

[boscoe99]

12.0 volts should start it. Try it and see. Let us know. This is how we learn.

[99yam40]

well you can always carry one of those Lipo jump packs or jumper cables to jump from the other battery if the start battery gets too low

[TownsendsFJR1300]

well you can always carry one of those Lipo jump packs or jumper cables to jump from the other battery if the start battery gets too low

I only have one battery and simply monitor the voltage (and listening) with cold start up and while underway(volt meter).

I've never had two batteries.

If there's any doubt about the batteries life, it's replaced.



* I do carry a very heavy duty and long set of jumper cables thou.. Never had to use em..
Along with a paper shop manual, owners manual, tool box, etc.

.

[Lumpo414]

This being a brand new group 31 battery with 195 reserve im hoping to see little to no voltage loss after a day on the water running my Hummingbird.

[99yam40]

Do you run the plotter while motor is off a lot?
motor running even at low RPM still charges battery

[Lumpo414]

Really i hardly ever use my sonar just want to be able to if wanted. My old battery wasn't big enough and kept shutting my sonar off when i started motor. Just hoping bigger battery is the cure.

[99yam40]

a bad cell in the battery, connection in or outside of the battery, or cable/wire can cause that to happen.

monitoring voltages at different places when you place a load on the system helps tell where the problem is.
hope you solved it with a new bigger battery

[zenoahphobic]

I find setting any low voltage alarm is practically useless but for the purpose to protect the battery: that is at 11 to 11.5 volts, at almost flat. Just like a fuse is to protect wiring not the “appliance”.
I agree with Townsend’s idea, if you have only one battery you tend to know when it is needed to be replaced. I’ve never had a dual battery system get me out of trouble, just costs me an extra battery every couple of years.
I think the OP wants to avoid the inconvenience of his equipment resetting after the starting voltage drops during the starting process. I suffer annoyance every time I start my car in my driveway, the proximity sensors set off an alarm every time I get in and turn the ignition on, I then press them off only to have the alarm return after starting and having to press them off again!
There is nothing you really can do about this, other than already said to have a separate battery only for starting. Some devices are smart enough to allow return to where it was though, and probably will be the norm as technology progresses.

[TownsendsFJR1300]

That Hummingbird draws VERY LITTLE from the battery.

If just the slight draw is that far (voltage drop) and that fast, that original battery sounds suspect to me...