After market battery isolator question

[fishingwithblue]

I'm flipping through the manuel on my Evenrude 200hp 2004 year outboard and in the battery section is says to never install an after market batt isolator. It goes on to say it has a feature that can charge the cranking and acess. batt at the same time. It doesn't say what could result if I did. Any advice? Is this kinda like when they say only use Evenrude oil or could I mess the engine up installing the BlueSeas add a battery system?

[whatknot]

Blue,

Call Blue sea systems tech support.

[randlemanboater]

I guess it would be possible to burn up the alternator if both batteries were really low and pulled a lot of amps at the same time. But I would think that would be rare.

[phatdaddy]

might be referring to shutting the iso switch to the off position while engine is running?

[cterrebonne]

2004 200 DI?
i will have to check tomorow at work to see if those has the rec/reg built in the emm or if its stand alone. but as i recall omc made a battery isolator like the blue sea. word of advice if the rec/reg is in the emm there are expensive to replace.

[THEFERMANATOR]

You don't want to run an isolator on any magneto system. An isolator loses .8 volts through the diodes, and they provide no direct battery condition to dampen the AC current spike that magneto charging systems put out. If your going to run one, make certain that it is meant for it. I personally just use a battery switch.

[spareparts]

what about a battery combiner, I've only installed two of them( just found out about them). You can set the on and off voltage settings for the system to charge

[fishingwithblue]

I was planning on installing the Blue Seas system Whatknot did on his boat. It has a battery switch with on, off and combine for emergency start and a relay to isolate the batteries. Hook it up and turn the switch to on and it only uses the cranking battery when cranking. Then when I turn the boat off and have the vhf, GPS, radio and bait tank running it only draws from the 2nd batt. When you run the boat it charges both. Like Whaknot said set it and forget it. But now, after reading through the book i'm worried I will screw up the engine installing this system. 200 hp Evenrude Direct Injection 2004

[cterrebonne]

guest makes these that are in the EJ accesory book
EJ P/N 508362 for the dual batt and Ej P/N 503091 for the triple batt set up

ones a 2420a model and the other us 2424

[whatknot]

http://bluesea.com/viewresource/92

Battery Isolators are a common method of distributing charging current to multiple battery banks while assuring that the batteries remain electrically isolated during discharge. These devices are electrical "one-way check valves" that allow current flow to, but not from, the battery. Their disadvantage is that the diodes used in these devices cause a voltage drop that consumes charging energy, creates heat, and causes batteries to be undercharged. Alternators with external voltage sensing can correct for the undercharging problem, but voltage drop and the heat generated remain a problem. Battery isolators generally cannot be used with outboard motors that share a common wire for charging and starting.

Automatic Charge Relays (ACR's) are becoming a popular method for achieving the same goal as isolators, but they work on a different principle. Instead of using diodes to block current from flowing in both directions, ACR's use mechanical relays controlled by a circuit that senses when a charging source is being applied to either battery. When a charge is being applied, the ACR closes after a short time delay and connects the two batteries. When the circuit senses that the charge is no longer present, the ACR opens after a short time delay. This delay assures that the ACR does not open during temporary voltage sags due to load start-ups. ACR***8217;s can be used with outboard motors and inboard/outboard (I/O) installations.