How About a Boost?

[RJSakowski]

I’m trying to grasp what you did . Your taking a slightly discharged trolling motor battery and stepping up the voltage above say 14volts at 10 amps to charge the outboard motors battery ?

The booster steps up the voltage to 15 volts to provide 10 amps of charge current. Ten minutes of charging will provide enough charge on the dead battetry to start the motor. The booster will provide 15 volts , 10 amps with an input as low as 8 volts. In theory, I could use a dead battery to charge a dead battery, squeezing the last few electrons out. (A dead battery would be one at 11 volts or less). I seldom completely discharge either battery.

 

[Alcap]

That’s kind of what I thought you were doing ! Fantastic! Have you tried it out yet ?

 

[rwm]

This is brilliant!
Robert

 

[RJSakowski]

That’s kind of what I thought you were doing ! Fantastic! Have you tried it out yet ?

Both my batteries are fully charged so not on the boat. I have fed it into a .8 ohm load though and it was putting out 10 amps with less than 11 volts on the supply battery.

 

[rwm]

Ya know. If these are not in production, I think you could sell these. Many boats have 2 batteries and it is not unheard of for some idiot to run them both down too low to start the 496. All you have to do is leave the switch in the ALL position, turn up the radio and open the cooler. Or some variation of that....

 

[extropic]

@RJSakowski

The link you posted for the "boost buck" sold at $17.99, but the sellers "re-listing" is $117.99. Crazyflation.

A search shows it elsewhere for $23.49.

600W DC-DC Step Up Boost Buck Voltage Converter Power Supply Module 16A | eBay

Input Current: 16A (MAX). - Enhance heat dissipation over 10A operation. - Output Current: 12A MAX ,over 10A enhance heat dissipation. - Properties: non-isolated step-up module (BOOST). - Do not exceed the maximum arc distance electricity.

www.ebay.com

Thanks for the thread and the detailed explanation.

 

[Flyinfool]

So, just thinking out loud, if your dead charge battery is at 8V and you are putting out 15V at 10 A to charge the starting battery. that means that the dead supply battery has to be able to hold that 8V while outputting ~20A.

 

[rwm]

So, just thinking out loud, if your dead charge battery is at 8V and you are putting out 15V at 10 A to charge the starting battery. that means that the dead supply battery has to be able to hold that 8V while outputting ~20A.

This is true. Energy must be conserved. I am thinking that a lot of times, the battery is just dead enough not to crank the engine and just needs a little help.