Perko battery switch installed, need some clarification

[PDubs]

I have two batteries on one switch: Perko 8501DP. I asked the guy about using the switch as I was under the impression that I would be able to start up in position #1 (where my crank battery is) and while the boat was running, move the switch to "ALL" to charge both batteries. He strongly advised against this and mentioned that you essentially pick which battery to run off of and use only that battery when the boat was on.

I'm not convinced he does any mechanical work and seems more of a "front of the house" type guy. I thought the Perko switch I purchased allows for moving the switch while the boat was running. I realize you don't turn it to "OFF" while boat is running, but I thought I could at least go to "ALL" to charge the crank and house bats. Did I get the wrong product?

 

[Fireman431]

Re: Perko battery switch installed, need some clarification

In general, he's correct. If your cranking battery is hooked to '1', and your deep cycle is on '2', then you would start the battery on bank 1. after shutting down, electronics, stereo, etc run from 2. Go back to 1 when you're set to leave to access the cranking battery.

If you're running (idle) on 1, you can switch to 'all' without a problem. Perko install instructions advise not to go from 'all' to either bank alone while running, but I can't remember why.

When charging them out of water (trickle charger), set it on 'all' or do each bank individually.

 

[barbosam]

Re: Perko battery switch installed, need some clarification

Ya he is right, it is not recommended. Check out the instructions that come with the switch or go to the perko site, they have good documentation listed on the website to go with these switches.

When I use these switches I set it up so that neither battery is dedicated to starting or for house operations. I have it wired so that everything will run off of what ever battery is selected. Then when i am ready to leave the dock ill set the switch to battery 1 and start the engine from that battery. Then when I'm ready to head back I switch it to battery 2 and start the engine from that battery. This way both batteries will get a charge that day. Also, with this setup, you will only have the potential to drain out one battery at a time. Otherwise you could be out all day running accessories off of one battery draining most of the juice out of that one, then you might have a problem with your engine and you drain the second battery trying to crank it over, and now you have two dead batteries and no shot at getting your engine started.

If you are going to run dedicated start and house batteries you should have an automatic charge relay so that both batteries will recieve some charge when the engine is on.

Just a suggestion, that's how I do it.

 

[PDubs]

Re: Perko battery switch installed, need some clarification

Thanks for the clarification guys, glad I asked first before shorting out the alternator, etc. I don't know where I had it in my head that I could just move the switch ad hoc but it looks like I need to read their documentation some more.

 

[Fireman431]

Re: Perko battery switch installed, need some clarification

Like I mentioned, you can start on bank 1 and then switch to "all" for the ride home. This will charge bank 2 while the engine is running. It just advises not to go from "all" back to a single bank while running.

You can turn it to "OFF" while the engine is running, but that had better be to disconnect the batteries in the event of a fire or electrical meltdown only...

 

[Pez Vela]

Re: Perko battery switch installed, need some clarification

PDubs, you are completely correct, the salesman was incorrect. The one thing you cannot do is turn the battery selector switch to "off" with the engine running. Feel free to move the switch between 1-BOTH-2 anytime you wish.

 

[alws]

Re: Perko battery switch installed, need some clarification

So if your using the battery that your electronics is running off of and start the motor it will not affect your electronics?

Whenever I'd fire up the motor on the lake fishin I'd always switch to the primary battery.

 

[Fireman431]

Re: Perko battery switch installed, need some clarification

Here is the phrase that you're looking for from the installation manual for the 8501:

(2) Always STOP engines before switching to ?OFF? position. Make-Before-Break feature allows switching between
1-all-2 positions with running engines.

Here is a link to the PDF installation pages:

http://www.perko.com/images/catalog/pdf/Fig%208501-8504%20Inst%20(8500INS1).pdf

 

[Silvertip]

Re: Perko battery switch installed, need some clarification

So if your using the battery that your electronics is running off of and start the motor it will not affect your electronics?

Whenever I'd fire up the motor on the lake fishin I'd always switch to the primary battery.

The thought that starting an engine will fry electrics is absurd. Your boat came originally with one battery did it not? There are a gazillion one-battery boats operating all sorts of electronics with absolutely no issue. Besides -- most electronics these days have under as well as over-voltage protection so if voltage gets too high or too low they shut off. No harm - no foul. To carry this one step farther, why folks insist on powering stuff directly from one battery or the other even though they have a switch amazes me as it defeats the versatility of the switch. Wire every cotton pickin' accessory on the boat, including the feed to the fuse panel to the COM terminal on the switch. Now you have true versatility. You can charge either or both batteries from the engine, run the accessories from either or both batteries, start the engine from either or both batteries and kill the entire system with the flick of a switch. And you can indeed make switch selections anytime so long as the switch is a make before break version which most are these days. The ONLY accessory wired directly to a battery should be an automatic bilge pump and it should go to the largest battery so that even with power turned OFF at the switch, the pump can still run while you are away.

 

[barbosam]

Re: Perko battery switch installed, need some clarification

good find fireman, I knew that info was on their site somewhere. I guess I was a little off, I thought it was not adviseable to move the switch at all when the engine is running, but it looks like you guys are right.

Silvertip, Agreed. That is the setup I was trying to describe earlier.

 

[PDubs]

Re: Perko battery switch installed, need some clarification

Fireman - Thanks for that find, clears it right up.

Silvertip - I additionally agree on the setup and will have to double check with my shop on how they installed everything because your scenario would be ideal.