Isolater vs perko switch

Anyone know the difference between the 2? or are they the same thing? My Sanger has a blue Battery isolator next to my starboard side Battery.. What does this isolator do? does it run both my starboard and my port side batteries together all the time? or 1 vs the other? not really sure what this is...

is it the the Blue Sea ACR?

http://bluesea.com/category/2/productline/overview/387

If so, it's a voltage sensing relay that will isolate your starting battery when your second battery drops below a certain voltage threshold. there's an optional wire on the ACR as well that will temporarily disconnect the 2nd battery during cranking "to prevent damage to sensitive electronics". some don't use this. the ACR by itself can not be used to manually combine both batteries to aid in starting during an emergency (start battery low/dead) UNLESSS you add their Blue Sea manual switch which has a manual combine position which bypasses the ACR. you need to take a close look at how it's wired up.

oh, and it will combine both batteries in parallel when their is a charge present as long as the start batt is above 12.8 (i think that's the number, basically enough to crank).

My guess...it connects the two battery's when the ignition is on, and isolates the batteries when the ignition is off.

no its not it.. it is like this one on the right side..

Isaac-

Most isolators are diode-based. Lots of them look like little audio amplifiers, with cooling fins. They are automatic, in that they allow both battery banks to charge when the motor is running, but then the diode prevents current from flowing out of the starting battery to power a stereo or other accessory device. The isolator is designed to keep your cranking battery topped off, so when it is time to go, you can.

A Perko switch is really only a switch, yet a big one. They are not automatic. Perko Switches require thought, and there are "a million" different ways to wire a dual battery system... So many, we should skip that part of the discussion for now. Again, the thing to remember and understand is that Perko switches rely on YOU to make sure the electrical system is being charged and discharged properly. Run one battery dead while listening to the stereo, only to remember that you did the same thing to the OTHER battery the weekend before is not fun. Accidentally switch the Perko to OFF while the motor is running, and you will usually fry your voltage regulator.... One last time, the Perko is not automatic; it replies on you to make sure you do the right thing.

Your isolator is PROBABLY set up so that you have the starter motor, and the other boat-related circuits tied to one battery. Then your stereo, any BLING lights, etc. would be tied to the other battery. You run the stereo dead, and you are okay, 'cause the starter motor is going to crank over from the starting battery. Once running, the alternator will provide almost all the alternator's charging juice to both batteries.

Notice I say "almost all" the charging juice will go to the batteries?????

A diode-type battery isolator makes you pay a price for the automatic operation. A diode will drop your charging voltage by .7 volts. if your alternator is putting out 14 volts, your batteries will "see" 13.3 volts. The biggest problem with diode based isolators is this very fact. Your batteries never receive the full charging voltage that your alternator can deliver.

An Automatic Charging Relay, (ACR) like the Blue Sea Systems item that Bruce Mac posted above is wired basically the same way, but uses voltage sensing to detect a charge. When it know for sure a charge voltage is present, it closes a switch, (relay) that allows both batteries to charge at the full charging voltage, again as Bruce Mac points out.

I put the Blue Sea Systems 7610 in my boat this year. I am still watching and learning, (I even re-read some stuff today to make sure we were really doing the right thing with it) but so far, I think that using an ACR, (from Blue Sea, or from any of the other guys who are building them) is the best device to have. I do not have a battery switch, and do not want one. But back to your original question, they are different, and they are not the same thing. Check to see if you can find a part number or model number for the isolator thingie you have. If it is diode-based, you might want to addd an ACR to your upgrades list.


Phil
Kicker

(Message edited by philwsailz on June 29, 2009)

(Message edited by philwsailz on June 29, 2009)

Hah, you posted the pic while I was editing...

That thing is almost certainly diode-based... You probably do want to add an ACR to your grocery list... Not an emergency but you batteries will like the ACR better when compared to a diode isolator...

Phil

Phil, thanks for that.. of course the reason for the question, is that Im trying to figure out why my headunit cycles off and on when my volume is more than 50% when I want to play it REALLY loud.
My initial thought is that its not getting enough juice because all my "bling toys" (amps and stereo) are running off 1 battery? What do you think?

Amps and head unit all should be on the same battery.

Is the head unit going off, or is something else going on and off? The H/U going off is unusual... A weird question: Are you using the speaker wires from the head unit for anything, and if not, are they totally taped sealed off to prevent shorting? Lots of times head unit speaker wires come pre-cut, and if they are shorting, to something else or to each other, that could certainly cause the head unit only to turn off at higher volumes...

Phil

Do all ACR's need to have the ignition switch wired in to work properly? I have the SurePower 1314 from PolarBill which is a great deal for other WW'ers by the way $65.

no, it's optional on both the Blue Sea and the 1314. i run the 1314, but it's different than the blue sea in that the optional wire from the blue sea seperates the batteries during cranking ALWAYS, unless a manual switch is used to bypass the acr and combine. the Blue Sea ACR is not capable of the current loads with a combined emergency start. that's why imo if you were to go the blue sea route, it would be best to get the add a battery kit so you can bypass the acr in an emergency. the 1314 from brett is different in that when the start assist wire is hooked up, it will sense if the start battery is low (i think below 11.8) and if it is and the second battery is above 11.8 it will use the 2nd battery to provide a short "boost" to the cranking current. the feature can be wired to work automatically, or you can install a small fused switch to make it manual. i have mine wired without a switch.

phil, the interior speakers are running off the deck.. the KMT6's are running off a HiFonics amp 1 pod to each channel on the amp.. JL E4300 amp bridged to power the Kicker sub.

At anything less than 50% volume its decent loud and sounds great.. the only time this happens is when the power is greater than 50%.. when I would like to play it REALLY loud it starts to cut the deck off but not the amps.. just the deck.. when I catch it really quick on the power up and I lower the volume it plays normal.. just wish I could play it REALLY loud sometimes..

I think that in most instances, the ignition switch wiring is optional, certainly that is the case with the Blue Sea 7610.

The ignition switch forces isolation, just to MAKE SURE that any sensitive electronics are not exposed during cranking, that is how the Blue Sea Systems manual explains it anyway..

I do not know what electronics we have that would be wired to the stereo or house battery that could be deemed as sensitive...

Either way, the 7610's basic function for our needs is unchanged, whether you use the starter switch wiring or not. I would have to go look at the Sure Power schematic to know for sure...

Phil

Okay Isaac, that is nuts...

How many interior speakers? DO you have more than one speaker on any head unit wire?

no, 4 interior speakers wired to the deck..

Deck is a Sony with Sony Xplode interior speakers

Another question about isolators...

Is there a difference between auto and marine units? Do they have to be mounted in a dry space?