Dual Battery Switch

eula30

Petty Officer 1st Class
Joined
Mar 16, 2003
Messages
231
Hi, I just bough a used boat and it came with dual batteries and a red switch, Switch function Off-1-All-2. I have an Evinrude 90HP, This Evinrude will be able to charge both batteries or will it charge only one? If it Charge Both Batteries where the switch setting goes 1- All or 2. The way the switch is setup is 1-left Battery all-Both Battery 2- right Battery. Any Help please. <br />Thanks
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Dual Battery Switch

Hi, Eula.<br /><br />I am not a fan of battery switches. I have seen too many powerpacks and ECMs destroyed when someone switched the battery switch with the key on.<br /><br />If you have an electric troller, use one, deep cycle battery for that. Use the other only for starting, instruments and electronics and charge it with your engine. Charge the deep cycle with a charger when at home.<br /><br />If you have no electric troller, just parallel the batteries and use them for everything as well as keeping both charged with your engine.<br /><br />Now, that said, the switch allows you to use and charge one battery or the other, both or neither. I suppose the theory is that you have a safe backup if you kill one battery, and that you can turn both off to protect against slow leak discharge.<br /><br />Good luck. :)
 

peterbo3

Petty Officer 3rd Class
Joined
Mar 8, 2003
Messages
79
Re: Dual Battery Switch

Evening Eula,<br />If that battery switch is red chances are it a top quality Perko brand made in the US. The later model Perkos have a "make before break"function.This means that the connection to the battery you are changing to is made before the original battery is isolated. This function ensures that your charging system is always running through a closed circuit.However should you turn the switch to the "Off" position while the motor is running you can do major damage to your O/B charging system.<br /> To check which battery is number 1, remove the black ground wire from one battery & set the switch to 1. Turn your ignition key to the on position. If your alarm "cheeps" & the instruments light up then the battery still connected is number 1. If nothing happens, reconnnect your ground cable & repeat the process with the other battery. It is a good idea to repeat the process rather than make an assumption about which battery is number 1 because you may have a faulty switch, battery or even a loose connection. <br />Regards,<br />Peter.<br />PS. JB is right. All changover battery switches do have a little bit of the Law According to Murphy built in. If visitors on your boat turn that switch to "Off" accidently it will be a very expensive repair.
 

kshatzer

Seaman Apprentice
Joined
Jun 17, 2003
Messages
30
Re: Dual Battery Switch

Amen to the "good info" post. I just bought a boat with dual batteries and a Perko switch. First time I've had duals and didn't know about switching only with the key off. tHANKS FOR THE INFO.<br /><br />kEN
 

Ralph 123

Captain
Joined
Jun 24, 2003
Messages
3,983
Re: Dual Battery Switch

If you never want to be stuck due to dead batteries, go and buy a battery combiner like those sold by West Marine (e.g., Combiner 150). They allow the batteries to be charged at the same time and discharged individually. This prevent you from killing both batteries and not being able to start your engine to get home :-( <br /><br />I have 3 batteries in a twin boat. 2 batteries are dedictaed to starting the engines and running the trims while the third handles everything else (the "house" battery")<br /><br />When either alternaor is charging, the combiners kick in and distribute the charge across all three batteries. When the engines are off only the house battery is being drained. <br /><br />This sort of configuration require 4 on/off switches (engine 1, engine 2, house and 1&2)<br /><br />1&2 parallels the starting batteries to allow for a dead starting battry should it ever happen.
 
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