Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 17-04-2017, 12:48   #1
Registered User

Join Date: Nov 2011
Location: Santa Barbara, CA
Boat: Catalina 270LE, 27'
Posts: 11
Two batteries, different ratings

I am buying a Catalina 270LE and was inspecting it when I discovered the two batteries in the bank are rated differently. I've read before that batteries shouldn't be different ratings or ages, but how different is bad? They are very similar, they both look new, and bottom line is I would hate to have to toss them out and buy two brand new batteries... but then again, I would hate even more to be damaging them or other systems on the vessel.

The specs, battery #1 (WestMarine): Model 15020316, MCA@32F = 615, RC 130, Ah@ 20hr = 75

#2: Model 15020183, MCA = 675, RC = 120, Ah = 65

I don't know if these are significant differences, if there is a solution that doesn't require tossing both batteries or if I can keep one or both? Maybe I could transfer one to a different purpose and separate them?
__________________

zeitgeist is offline   Reply With Quote
Old 17-04-2017, 13:35   #2
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2007
Location: Santa Cruz
Boat: Boatless Again
Posts: 4,694
Re: Two batteries, different ratings

The operative word is "shouldn't", not "can't". Combining the two batteries you have will not damage anything. People who tell you otherwise are simply misinformed.

If the battery bank gets too weak to meet your needs, you "should" replace it with batteries of similar characteristics.
__________________

donradcliffe is offline   Reply With Quote
Old 17-04-2017, 13:40   #3
Registered User
 
ranger42c's Avatar

Join Date: Aug 2012
Location: Maryland, USA
Boat: 42' Sportfish
Posts: 4,097
Re: Two batteries, different ratings

Quote:
Originally Posted by zeitgeist View Post
I am buying a Catalina 270LE and was inspecting it when I discovered the two batteries in the bank are rated differently.

Are they really in "the bank" (the same bank)?

Would have expected the boat would have a start bank and a house bank... and it's not impossible a "bank" is made up of only one battery.

-Chris
__________________
Selby Bay, South River, Chesapeake Bay, USA.
ranger42c is offline   Reply With Quote
Old 17-04-2017, 14:12   #4
Registered User
 
Stu Jackson's Avatar

Join Date: Jan 2011
Location: Cowichan Bay, BC (Maple Bay Marina)
Posts: 7,903
Re: Two batteries, different ratings

ranger could be right. Have you looked in their catalog? One could be deep cycle and the other start technology.
__________________
Stu Jackson
Catalina 34 #224 (1986) C34IA Secretary
Cowichan Bay, BC, (Maple Bay Marina) SR/FK, M25, Rocna 10 (22#) (NZ model)
Stu Jackson is offline   Reply With Quote
Old 17-04-2017, 15:34   #5
Registered User
 
PommyDave's Avatar

Join Date: May 2016
Location: Sydney, Australia
Boat: Top Hat (Mark III) 25 feet
Posts: 79
Re: Two batteries, different ratings

Starting batteries are usually rated in Cold-Cranking Amps, while deep-cycle batteries are rated in Amp/hours.

Cold Cranking Amps (CCA) CCA is a rating used in the battery industry to define a battery's ability to start an engine in cold temperatures. ... The rating refers to the number of amps a 12-volt battery can deliver at 0F for 30 seconds while maintaining a voltage of at least 7.2 volts.

The normal storage battery rating is the AMP-HOUR RATING. This is a unit of measurement for battery capacity, obtained by multiplying a current flow in amperes by the time in hours of discharge. (Example: A battery which delivers 5 amperes for 20 hours delivers 5 amperes times 20 hours, or 100 ampere-hours.)
__________________
Cheers,
Pommy Dave
VK2DMH
PommyDave is offline   Reply With Quote
Old 18-04-2017, 10:35   #6
Registered User

Join Date: Nov 2011
Location: Santa Barbara, CA
Boat: Catalina 270LE, 27'
Posts: 11
Re: Two batteries, different ratings

Thanks for all the input so far, I am less worried about them now. I also need to buy a new battery charger and it seems that the new models have a feature that monitors individual battery levels and maintains them individually. (such as This one

The first is listed as a "Deep Cycle Flooded Marine Battery", the second is listed as a "Deep Cycle Dual Purpose Marine Battery"

I did not verify if the batteries were connected in series, parallel, or separately; they are located next to each other in the same forward compartment, underneath a bench seat.
zeitgeist is offline   Reply With Quote
Old 18-04-2017, 13:17   #7
Registered User
 
ranger42c's Avatar

Join Date: Aug 2012
Location: Maryland, USA
Boat: 42' Sportfish
Posts: 4,097
Re: Two batteries, different ratings

Quote:
Originally Posted by zeitgeist View Post
I also need to buy a new battery charger and it seems that the new models have a feature that monitors individual battery levels and maintains them individually.

The first is listed as a "Deep Cycle Flooded Marine Battery", the second is listed as a "Deep Cycle Dual Purpose Marine Battery"

I did not verify if the batteries were connected in series, parallel, or separately; they are located next to each other in the same forward compartment, underneath a bench seat.

You'll want to understand wiring before deciding how to proceed.

And if they're connected... you'll want to understand whether it means you've got a single combined start/house bank... or whether you haven't found the start (or house) battery yet.

You might be better served by the ProNautic line of chargers, if you choose to stay with the ProMariner brand. (FWIW, Sterling mostly sells the same products, slightly different names.)

-Chris
__________________
Selby Bay, South River, Chesapeake Bay, USA.
ranger42c is offline   Reply With Quote
Old 18-04-2017, 13:31   #8
Registered User

Join Date: Aug 2011
Location: Lower Chesapeake Bay
Boat: Bristol 27
Posts: 5,818
Re: Two batteries, different ratings

When I first bought my boat, I wanted to get the engine started first so I ran over to Walmart and got a car battery ($75.00) to start the old diesel.

This in 2011.

The diesel failed a month or so later as did another junker diesel I installed.

I then installed a new outboard on a bracket with pull start and no alternator.

I then installed a 100 Watt Solar Panel with controller and bought an Interstate Deep Cycle Flooded Battery.

I hooked the Deep Cycle Battery in parallel with the Walmart Car Battery. This served as my "House Bank." The solar charged the batteries.

The Interstate Deep Cycle Battery failed after 5 years. The Walmart battery is still installed along with a Deep Cycle Battery I got from Advanced Auto.

My goal is two deep cycle batteries in parallel of the same type, but I hate to get rid of something (the Walmart Car Battery) that's working.
thomm225 is online now   Reply With Quote
Old 18-04-2017, 13:53   #9
Registered User

Join Date: Sep 2016
Location: Long Beach, CA. Moving to STT 11/18
Boat: 45 Leopard- Had a 42 Leopard- Sunk by Irma
Posts: 113
Re: Two batteries, different ratings

Is there a battery red switch with "1", "2", and "All" or "Both"? If so you have 2 banks, one for starting and one for house. That's why there are 2 different types of batteries, one a starting/ deep cycle and one a true deep cycle. Don't overthink it, if the charger works keep it.
LLizzard is offline   Reply With Quote
Old 18-04-2017, 17:32   #10
Registered User

Join Date: Aug 2011
Location: Lower Chesapeake Bay
Boat: Bristol 27
Posts: 5,818
Re: Two batteries, different ratings

Quote:
Originally Posted by LLizzard View Post
Is there a battery red switch with "1", "2", and "All" or "Both"? If so you have 2 banks, one for starting and one for house. That's why there are 2 different types of batteries, one a starting/ deep cycle and one a true deep cycle. Don't overthink it, if the charger works keep it.
The switch means absolutely nothing.

It's all about how it's hooked up.

Now I'm getting worried about folks that have zero knowledge of electricity or electronics especially on a boat.
thomm225 is online now   Reply With Quote
Old 19-04-2017, 00:38   #11
Registered User
 
Doug4bass's Avatar

Join Date: Jan 2014
Location: Marquette, Mi
Boat: Catalina 385
Posts: 76
Re: Two batteries, different ratings

Quote:
Originally Posted by thomm225 View Post
The switch means absolutely nothing.

It's all about how it's hooked up.

Now I'm getting worried about folks that have zero knowledge of electricity or electronics especially on a boat.


Meooooow........
Doug4bass is offline   Reply With Quote
Old 19-04-2017, 05:28   #12
Registered User

Join Date: Aug 2011
Location: Lower Chesapeake Bay
Boat: Bristol 27
Posts: 5,818
Re: Two batteries, different ratings

Quote:
Originally Posted by Doug4bass View Post
Meooooow........
Ruff-Ruff, ruff, ruff, ruff.............
__________________

thomm225 is online now   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
I Only Have Two Batteries - Which Batteries Should I Use? LifesAnAdventure Electrical: Batteries, Generators & Solar 11 04-06-2014 19:29
Two Engines, Two Alternators, Two Banks scurvy dog Electrical: Batteries, Generators & Solar 2 16-02-2014 06:48
can I mix different rudder angle indicator and different autopilots awab Marine Electronics 11 24-04-2013 15:25
Two solo cruisers , Two boats OR Two Captains One Boat colo.sail General Sailing Forum 8 17-12-2011 17:36
Two Engines - Two Different Problems perkie43 Engines and Propulsion Systems 6 29-06-2011 11:32

Advertise Here


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 06:57.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×

ShowCase vBulletin Plugins by Drive Thru Online, Inc.