WELCOME TO RIVER DAVES PLACE

Battery question, system with AGM and Wet Cell

humvkev

Well-Known Member
Joined
Sep 24, 2020
Messages
52
Reaction score
29
I am going to be given a new Optima red top. Currently I have a two battery bank system for the whole boat with a Perko switch. Can I parallel the current Deka marine batteries (non AGM) and use the Red Top as a starting only battery? I don't see a reason why it wont work but before I do it I want to double check. Can I run the Perko switch on ALL while the engine is on charging both AGM and Wet Cell batteries without any issues? This winter I am likely going to add a Blue Sea Isolator so that I don't have to change the Perko switch whenever we run the stereo with engine off, will this be a problem as well using an isolator. The Deka batteries are old and this winter I will probably be replacing those as well but I may get cheap Marine batteries from Walmart, Costco, or Autozone... Not sure I will get AGM Marine batteries for stereo set up because I have read that many of you get the cheap batteries and just replace every 2-3 years.

Thanks!
 

TITTIES AND BEER

Well-Known Member
Joined
Sep 28, 2007
Messages
13,705
Reaction score
13,671
I ran 3 yellow tops 2 for tunes 1 for starting , when I was running up lake I would put on all
 

humvkev

Well-Known Member
Joined
Sep 24, 2020
Messages
52
Reaction score
29
I ran 3 yellow tops 2 for tunes 1 for starting , when I was running up lake I would put on all
did you ever run AGM and Wet Cell batteries at the same time, one AGM for starting and the Wet Cell for Stereo? Do you see any issues with that?
 

Backlash

Well-Known Member
Joined
Jan 14, 2011
Messages
8,446
Reaction score
12,458
Not an expert by any means, but I would try and run the same type of battery for peace of mind. Take the old batteries to Interstate, trade them in for a few bucks and get yourself a second Optima. Then there's nothing to worry about.
 

Backlash

Well-Known Member
Joined
Jan 14, 2011
Messages
8,446
Reaction score
12,458
I'm also putting together a Blue Sea switch and automatic charging relay for one of our boats. It's been fun, but be prepared to drop a few hundred bucks on quality components when you get to that part of the project. 👍
 

humvkev

Well-Known Member
Joined
Sep 24, 2020
Messages
52
Reaction score
29
Not an expert by any means, but I would try and run the same type of battery for peace of mind. Take the old batteries to Interstate, trade them in for a few bucks and get yourself a second Optima. Then there's nothing to worry about.

I just might do that anyways. The batteries are old and they all need to be replaced. The last thing I want to do is cause a bigger problem because of the different types of batteries


Sent from my iPhone using Tapatalk
 

humvkev

Well-Known Member
Joined
Sep 24, 2020
Messages
52
Reaction score
29
I'm also putting together a Blue Sea switch and automatic charging relay for one of our boats. It's been fun, but be prepared to drop a few hundred bucks on quality components when you get to that part of the project. [emoji106]

I will be reaching out to you when I get there if you don’t mind.


Sent from my iPhone using Tapatalk
 

02HoWaRd26

Well-Known Member
Joined
Dec 19, 2007
Messages
8,143
Reaction score
16,570
I have two FullRiver agm’s as #2 and one Interstate regular old group 24 as #1 on the switch. I never run on all, and frankly the interstate seems so far to just be an insurance policy as i really don’t use it. Every once in a while I’ll use it just to start boat when we first launch just to give it an occasional load then go right back to bank 2. Doesn’t exactly answer your question as i don’t ever run boat on ALL nor should anyone, that’s typically just there Incase you have two low battery’s you can use both banks to get started. But two low battery’s on an alternator will never charge as much nor give you the output as just charging one.
 

humvkev

Well-Known Member
Joined
Sep 24, 2020
Messages
52
Reaction score
29
I have two FullRiver agm’s as #2 and one Interstate regular old group 24 as #1 on the switch. I never run on all, and frankly the interstate seems so far to just be an insurance policy as i really don’t use it. Every once in a while I’ll use it just to start boat when we first launch just to give it an occasional load then go right back to bank 2. Doesn’t exactly answer your question as i don’t ever run boat on ALL nor should anyone, that’s typically just there Incase you have two low battery’s you can use both banks to get started. But two low battery’s on an alternator will never charge as much nor give you the output as just charging one.
ok, so the Perko switch should not be run on all ever.... I will do that going forward. At times I ran it on all so that all batteries were getting a charge. When beached, I would move the switch to battery #2 because that is where the stereo amp is connected to. Going forward I will run them on either battery 1 or battery 2. Thanks!
 

Singleton

Well-Known Member
Joined
Feb 5, 2008
Messages
13,984
Reaction score
14,733
ok, so the Perko switch should not be run on all ever.... I will do that going forward. At times I ran it on all so that all batteries were getting a charge. When beached, I would move the switch to battery #2 because that is where the stereo amp is connected to. Going forward I will run them on either battery 1 or battery 2. Thanks!

Rule 1 - never switch from 1 to All or 2 once under power!

I start when with 1 and run on 1, then once beached and engine off move to 2 for the stereo. Plug boat in at night and all batteries get charged
 

Singleton

Well-Known Member
Joined
Feb 5, 2008
Messages
13,984
Reaction score
14,733
I have two FullRiver agm’s as #2 and one Interstate regular old group 24 as #1 on the switch. I never run on all, and frankly the interstate seems so far to just be an insurance policy as i really don’t use it. Every once in a while I’ll use it just to start boat when we first launch just to give it an occasional load then go right back to bank 2. Doesn’t exactly answer your question as i don’t ever run boat on ALL nor should anyone, that’s typically just there Incase you have two low battery’s you can use both banks to get started. But two low battery’s on an alternator will never charge as much nor give you the output as just charging one.

that is not how mine is rigged.
1 = dedicated start battery
2 = decorated stereo battery
ALL = pulls from both and alternator charges both

I start on 1, get to beach once engine is off switch to 2 for stereo. You should never move the switch from one position to another once engine is running!
 

Taboma

Well-Known Member
Joined
Apr 4, 2008
Messages
9,814
Reaction score
12,644
Rule 1 - never switch from 1 to All or 2 once under power!

I start when with 1 and run on 1, then once beached and engine off move to 2 for the stereo. Plug boat in at night and all batteries get charged

They used to say that, in fact they had separate terminals on some with field wire terminals that allowed switching under power. But I keep reading of late, it doesn't matter, so I don't know if it's certain alternators or they changed the switch design to make before break, so it's never truly an open circuit unless off ?? I don't switch mine out of old habits and not wanting to test what I read on the internet ;)
 

humvkev

Well-Known Member
Joined
Sep 24, 2020
Messages
52
Reaction score
29
that is not how mine is rigged.
1 = dedicated start battery
2 = decorated stereo battery
ALL = pulls from both and alternator charges both

I start on 1, get to beach once engine is off switch to 2 for stereo. You should never move the switch from one position to another once engine is running!

So if you were at the beach for a few hours and wanted to charge the stereo batteries, would you move switch to ALL before starting the engine so that you have power to start and the ability to put a charge to stereo batteries?


Sent from my iPhone using Tapatalk
 

02HoWaRd26

Well-Known Member
Joined
Dec 19, 2007
Messages
8,143
Reaction score
16,570
that is not how mine is rigged.
1 = dedicated start battery
2 = decorated stereo battery
ALL = pulls from both and alternator charges both

I start on 1, get to beach once engine is off switch to 2 for stereo. You should never move the switch from one position to another once engine is running!


Hmm I’ve never heard not to switch, however like i said it’s a quick switch, however based upon the wiring guy who has taught me 12v wiring (he’s only one of the best mil spec wiring guys in Motorsports and worse for some of the biggest teams in offroad, and Indy cars, also does quite a few marine systems for big high dollar guys doing restores etc) that’s what he told me to do just as then the battery gets an occasional load on it.

The average charging system isn’t designed to charge two battery’s even more two banks at once unless ran with an isolator. You will burn an alternator up in no time that way.

As well most alternators don’t charge at idle unless they are specifically set that way.
 

Singleton

Well-Known Member
Joined
Feb 5, 2008
Messages
13,984
Reaction score
14,733
So if you were at the beach for a few hours and wanted to charge the stereo batteries, would you move switch to ALL before starting the engine so that you have power to start and the ability to put a charge to stereo batteries?


Sent from my iPhone using Tapatalk

yes, that is what my mechanic has told me to do.
mine is rigged so stereo can never pull from the #1 battery. However alternator can charge both.
the newer ones are much smarter, I have 2007 technology
 

Singleton

Well-Known Member
Joined
Feb 5, 2008
Messages
13,984
Reaction score
14,733
Hmm I’ve never heard not to switch, however like i said it’s a quick switch, however based upon the wiring guy who has taught me 12v wiring (he’s only one of the best mil spec wiring guys in Motorsports and worse for some of the biggest teams in offroad, and Indy cars, also does quite a few marine systems for big high dollar guys doing restores etc) that’s what he told me to do just as then the battery gets an occasional load on it.

The average charging system isn’t designed to charge two battery’s even more two banks at once unless ran with an isolator. You will burn an alternator up in no time that way.

As well most alternators don’t charge at idle unless they are specifically set that way.

yep.
I only have 2 batteries. Looked at adding a third and the costs increased due to setting everything else up correctly.
 

Shlbyntro

Ultra Conservative
Joined
May 27, 2018
Messages
3,500
Reaction score
6,812
Almost all multi battery switches including Perkos have overlapping contacts and are safe to switch with the engine running so long as you don't switch them into the "off" position.

That being said, 3 batteries connected all at the same time can still overwork your alternator under less than perfect conditions so it is not recommended to leave the switch in the "all" position if you are running more than 2 batteries. But you can safely start off of "all" or switch through it.

I personally run 3 batteries (1 boat battery, 2 stereo batteries) charged through an isolator and use a Blue Sea dual isolated bank switch on my boat and my entire stereo system is electrically isolated from the rest of the boat save for the emergency parallel position on the battery switch
 
Top