Scarab add a battery (modification)

[Stan Fisher]

@Stan Fisher I did eventually get Optima dual purpose batteries. It was just an added expense, and I already had the spare Interstate from my old Sea Ray laying around. Here, I also added a dual port Charger.
https://jetboaters.net/threads/new-dual-bank-charger-and-agm-batteries.4689/

Welcome to the community Stan!

I grabbed an optima for my second battery but then realized they are only 55Ah batteries. Maybe not the optimum choice for running accessories. I'm wondering if I should have gone traditional battery with 90-120Ah capacity.
I understand the advantages to the AGM but capacity isn't one of them.

Thoughts?

 

[MikeyL]

Optimas offers two (2) series of batteries. And I do not mean type 27 or type 34.

Optima 27M's BLUES are 66maH. Product number 8027-127 D27M 27

If however you purchased the slightly less expensive 8016-103 D34M it is only 55maH.

Get the specs here: http://www.optimabatteries.com/en-us/shop/bluetop

There are significant other benefits to AGM batteries besides "capacity." It is my personal opinion you'll be very pleased over a course of years of ownership with your specific purchase. Good Luck and Happy Easter to you, Mikey Lulejian - Lake Oconee, GA

 

[ScarabMike]

I agree with @MikeyL. While these batteries might not have as high maH, you can use their charge completely, and they will charge up incredibly fast. As far as performance...... They have never given me any issues over the years of having them on various vehicles and boats.

 

[RFScarab]

Thanks ScarabMike for taking the time to do this. You made my project much simpler when at the local marine shop grabbing parts. All done and is a pricy project when all said and done with two new Optima batteries and all the parts. This will leave no concern on the water when running a stereo etc. during down time. Also added a Marinco on board dual bank charger. Took me a while but glad I did it. Great mod and thanks again ScarabMike!!!

 

[ScarabMike]

Glad I could help! Congrats on your new setup!

 

[Stan Fisher]

@ScarabMike - Hey did you use all 12 feet of your battery cable? I only ended up getting slightly over 10' of each color.. getting ready to embark on this mod. Hoping you had some left over.

 

[RFScarab]

You are good to go! I wound up with an extra 3 ft or so.

 

[RFScarab]

You might consider adding an onboard charger same time. So much simpler to top off your batteries instead of lifting the hatch to the motor and charging one at a time.

4 barrel connectors for 16ga wire (to extend wire from charger to second battery)
10ft black 10ft red 16ga wire
4, 3/4in stainless steel screws (for mounting charger)
10ft wire loom
Zip ties

Hope it turns out well.

 

[ScarabMike]

@Stan Fisher Yes sir. I made sure everyone has spare wire left. Better than not enough. Also, take @RFScarab advice. I love my charger.

 

[RFScarab]

Don't be mistaken this is all ScarabMike as he was first to the table with all of this advice elsewhere here on the forum with write ups second to none. Just adding a few thoughts. Thanks again ScarabMike.

 

[GIII]

@ScarabMike
A bit confused...
On the stock switch, the ECU and some other items are connected along with the battery on the common post.
Are you saying to put all of those on the new switch on #2 and put the battery lead on common instead?

 

[ScarabMike]

@GIII

Just duplicate the connections on the original to the new one, and add the second battery to the #2 slot.

 

[GIII]

thx thats what i thought... came out nice

 

[GIII]

Did exactly what Mike did and brought the boat down to my dealer/marina (MarineMax) for rack storage this season...
MarineMax told me they would void my electrical warranty if i didn't put the stock main power switch back in along with a battery isolator, since the boat has a stator and not an alternator... so I put this inline on the positive between the 2 batteries: http://www.amazon.com/gp/product/B000OTIPDQ/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

 

[ScarabMike]

Thats interesting @GIII. Im going to do some further investigating into this. The Isolator/switch has no issue with the stator as long as the battery connections are correct.

The battery isolator is not going to switch from a completely drained battery to the good one by itself. You need the special selector switch to make that happen. without that selector switch, all the money you have spent on the dual system is bypassed for the most part.

In normal conditions, the stator creates electrical energy from the magnets in the flywheel passing the coils that make up the stator. It sends this to the powerpack which stores and changes the voltage from AC to DC volts. The trigger, also under the flywheel sends a small voltage to the powerpack depending on the flywheel position, this releases the stored electricity to the coils which step it up and on to fire the plugs. The battery is only there to turn the motor over, it has no play on the ignition system. Stators output AC voltage to a rectifier and sometimes regulator. An alternator has the rectifier built in and outputs DC voltage and is rated at much higher amperage.

That isolator is basically doing the same thing you are doing with the switch. But, that isolator can go bad, and you will be dead in the water. I rather be able to control and see what the system is doing.

The MarineMax dealer here in FL applauded the setup.

 

[Stan Fisher]

I specifically asked my dealer if i do this mod if my warranty was at risk and he said no. Now he hasn't inspected the wiring yet but he didn't ask if I was going to use an isolator, and I described the use of the 1, 2, 1+2 switch as opposed to this special sw.

 

[ScarabMike]

@Stan Fisher I agree Stan. Not sure why they would tell him that. There are thousands of boats out there (outboards) that have a stator for charging, and this type of battery setup with no issues what so ever.

 

[Robert Sands]

Hi everyone, I'm new to the forum. So glad I found this website, it's such a huge repository of info on the Scarab. I've got a 195 HO Impulse and I'm going to be making this mod fairly soon. I want to make the mod with the boat still in the slip. If I drill holes for the battery box while the boat is in the water will that be an issue? As well, I'm going to buy a duplicate battery of the stock one the boat came with, but should I ensure it is fully charged before hooking the new and old batteries together? Thanks for your help. Take care.

Rob

 

[ScarabMike]

@Robert Sands Welcome to our online community! We are glad you found us.

Drilling the holes for the battery wont be an issue. The Scarab's hull is a solid piece of re enforced fiberglass, and the deck is basically welded with high tensile strength glue/epoxy. As long as you don't drill too deep into the deck, you will not go into the outer hull. Id keep the holes no deeper than 1/2" to 3/4". And even though there should be no risk of water intrusion, you want to use a sealer like 3M 5200 in the holes. It will also help the screws hold.

As far as the battery, you will be good to go using the same Intrastate. But remember, you are adding the second battery as a safeguard. I would buy a deep cell, or dual use battery. That way you can play your radio while using the deep cycle, and use the oem (cranking) battery to start the boat.

There is no issue with adding a different type of battery, as these wont be connected together unless you place the selector switch in dual mode.

I hope this helps!

 

[Robert Sands]

That helps a great deal, thank you very much.

I'm planning to use dual deep cycle Interstates, but out of curriosity if you run them together on the 1+2 instead of switching between the them, does it use power from both equally or does it drain one and then the other? I see you have the same batteries, how long do you find you can run music and lights off of a single battery? I guess I'm not really sure what the best power management strategy is. Thanks.

Rob