volts needed to start 150 Vmax

[colayn]

Can anybody tell me what is the minamul volts needed to start a 99 150 Vmax if all else is good on the battery?
I am running a lot of electronics on my start battery and want to set a low volts alarm on my sonar.
Have set down to 11volt alarm but it goes lower than that while cranking.
Thanks,
Paul

 

[99yam40]

Re: volts needed to start 150 Vmax

This is why most run a house battery for their electronics and start battery only for starting
Starting motor draws voltage down too much and resets or alarms electronics


On some motors if the voltage drops too far the motor will not spark properly make sure your battery and all connections and cables are in good shape

 

[orbanp]

Re: volts needed to start 150 Vmax

Hi Paul,

It depends on a lot of things! Here is a paper where are graphs of charge state of battery and voltage and other variables (temperature, charge or discharge, etc.)
The advice to have separate (or more than one) batteries is a wise one.
http://www.scubaengineer.com/documents/lead_acid_battery_charging_graphs.pdf

Peter

 

[Capt Ken]

Re: volts needed to start 150 Vmax

You need a least 9.5 volts at the starter when cranking.

 

[colayn]

Re: volts needed to start 150 Vmax

Thanks guys.
I would like to have separate battery, but just not enough room in this bass boat. Already have 3
My new sonar is power hungry and until I get some history just wanted to set a low volts alarm to be sure I can still crank her up. I will set it a 10.0 v and see if it alarms out when cranking
Thanks again,
Paul

 

[99yam40]

Re: volts needed to start 150 Vmax

If Start battery voltage drops to 10V or even 11V while just running electronics, when you hit starter I very much doubt that the starter will crank motor properly.

Probably be best to tap into trolling batteries with electronics as you do not want to not be able to crank motor out on water

You can measure battery voltage while cranking motor to see how low it drops while cranking

 

[Capt Ken]

Re: volts needed to start 150 Vmax

Yep, if your battery voltage drops to 10, you have a dead battery and won't start anything.

 

[Barnacle_Bill]

Re: volts needed to start 150 Vmax

 

[stylesabu]

Re: volts needed to start 150 Vmax

amps are more importanr than volts. have you given any thought to a lawn mover or motorcycle battery they're about half the size, run your electronics off this. then install battery isolator to charge it off the alt, but won't allow it to discharge other battery