Jayco RV Owners Forum
 

Go Back   Jayco RV Owners Forum > Jayco Tech and Tow > Tech Talk

Reply
 
Thread Tools Display Modes
 
Old 09-22-2013, 07:18 AM   #1
Senior Member
 
Mustang65's Avatar
 
Join Date: Nov 2012
Location: Clearwater, FL area
Posts: 3,671
Read Before Adding/Replacing Battery to an existing set, charging/performance issues

FYI

While researching battery maintenance/upgrades I came across this information that clears the air on adding/replacing/charging battery performance issues. Here is what was said regarding Parallel/Series and adding/replacing charging batteries. It is my understanding that the information came from Concorde Battery Company (Mfr of Military batteries). Very interesting information...

1. A new battery can be added in parallel with two (or more) older batteries. However, new batteries should never be connected in a series circuit with older batteries.


I then e-mailed them this question:

2. Why new and old batteries should never be connected in series?
-from the Director of Advanced Battery Technology at Concorde
The reason for this rule is because new batteries have a lower rate of oxygen recombination compared to aged batteries. When connected in series, the same current goes through each battery. The voltage of the new battery will get too high because of the lower oxygen recombination rate. The high voltage will force the new battery to be overcharged, leading to accelerated grid corrosion and loss of electrolyte. The high voltage on the new battery will also mean a lower than normal charging voltage on the remaining aged batteries so they will get undercharged, leading to sulfation and loss of capacity.



- from their Vice President of Manufacturing:
· In a series circuit, the capacity (A/H) input (charged) or removed (discharged) stays constant throughout the entire string. Therefore, if 50 A/H is removed from the string, it will be removed from every battery within that string.

· The measured voltage of a string is the sum of the voltages of the entire string. By the way, the current removed is not cumulative.

· Therefore, if you have a series string with several batteries and one is lower capacity than the rest of the string, the net voltage of the string will be supported mostly by the “new” batteries and may allow the string to be discharged below the capacity of the lower capacity battery.

· If this occurs and the discharge continues, the lower capacity battery will become completely discharged. Once the voltage of this battery reaches zero and the discharge (driven by the rest of the batteries in the string) continues, the current which is discharging the rest of the string will also travel in the discharge direction through the lower capacity battery, in effect charging it in reverse. This will destroy the lower capacity battery.


· In a parallel circuit, the voltage of all batteries within that circuit must always be the same as the rest.

· Therefore, any discharge (or conversely, recharge) will be governed by voltage.

· If there is a lower capacity battery in the circuit, only enough capacity will be withdrawn to discharge that battery to the same voltage as the rest of the circuit.

· If, for example, there is a battery that has 50% of the capacity of the rest, this battery will not produce as much capacity but it will not be discharged to any lower voltage than the rest of the circuit, thus protecting it from over discharge and subsequent reversal.
__________________

__________________
2013 Jayco Eagle 284BHS
250Watt Grape Solar Panel, MorningStar MPPT 60 Charge Controller
1500 Watt Ramsond PSI, 2 Trojan T145 Batteries (260Ah)
2 - AirSight Wireless IP Cameras (used as rear view cameras)
EnGenius WI-FI extender, D-Link wireless (n) modem
MagicJack Internet Phone
2012 Ford F150XLT, EcoBoost w/3.73
157" Wheel base, HD Towing Package

Our Solar Album https://www.jaycoowners.com/album.php?albumid=329
Mustang65 is offline   Reply With Quote
Old 09-22-2013, 05:37 PM   #2
Senior Member
 
tinlizzie23's Avatar
 
Join Date: Sep 2011
Location: Luray, VA (central Shenandoah Valley of VA)
Posts: 1,416
Good info. Thanks for posting it.
__________________

__________________
2003 Ford F-350 V-10 Crew Cab 4WD Long Bed
2004 Jayco Designer Medallion 29 RLTS 5th wheel
Bill, Gayle, and Mindi (dachshund)
Retired at last !

Nothing is foolproof to a sufficiently talented fool.
tinlizzie23 is offline   Reply With Quote
Old 09-23-2013, 11:54 AM   #3
Senior Member
 
Join Date: Feb 2010
Location: Tennessee
Posts: 110
I'm thinking that you would only connect in series if you have two 6V batteries and want 12V. Two 12V battries in series would produce 24V wouldn't it?

Nick
__________________
Pam and Nick Walters
28.5 RLS FW
Dodge 2500 HD
2 spoiled rotten Scotties
skymutt is offline   Reply With Quote
Old 09-23-2013, 12:12 PM   #4
Moderator Emeritus
 
Rustic Eagle's Avatar
 
Join Date: Apr 2011
Location: Michigan
Posts: 7,371
Yes.

Bob
__________________

2016 GM 2500HD 6.0L/4.10
2018 Jay Flight 24RBS
2005 Jayco Eagle 278FBS (retired)
1999 Jayco Eagle 246FB (retired)
Reese HP Dual Cam (integrated sway control)
Rustic Eagle is offline   Reply With Quote
Old 09-23-2013, 03:37 PM   #5
Senior Member
 
Mustang65's Avatar
 
Join Date: Nov 2012
Location: Clearwater, FL area
Posts: 3,671
It pretty much generic, whether you are talking 6 volt series/parallel, 12 volt series/parallel or 24 volt...... Granted RV's are 12 volt, so 6volt batteries could use both series/parallel depending on the number of batteries, as for 12 volt batteries, series would not apply only parallel, but the concept holds true for any combination of series/parallel setups.

Don
__________________
2013 Jayco Eagle 284BHS
250Watt Grape Solar Panel, MorningStar MPPT 60 Charge Controller
1500 Watt Ramsond PSI, 2 Trojan T145 Batteries (260Ah)
2 - AirSight Wireless IP Cameras (used as rear view cameras)
EnGenius WI-FI extender, D-Link wireless (n) modem
MagicJack Internet Phone
2012 Ford F150XLT, EcoBoost w/3.73
157" Wheel base, HD Towing Package

Our Solar Album https://www.jaycoowners.com/album.php?albumid=329
Mustang65 is offline   Reply With Quote
Old 12-15-2013, 07:30 PM   #6
Senior Member
 
David472's Avatar
 
Join Date: Feb 2011
Location: SW Ontario
Posts: 1,393
Keep in mind, each 12 volt battery is made up of 6 individual cells connected in series. Two volts each. The same principles apply when one cell is weaker.
__________________
Jayco Eagle 31.5RLDS
GMC Sierra 2500 HD
David472 is offline   Reply With Quote
Old 12-16-2013, 05:06 AM   #7
Senior Member
 
Join Date: Apr 2011
Location: Southwest Florida
Posts: 748
Quote:
Originally Posted by tinlizzie23 View Post
Good info. Thanks for posting it.
X2 - Mustang65, thanks for doing the research on this one. There are legitimate technical reasons things work well (or don't) and we don't always know what they are. Your post did an excellent job with the new / old battery issue - that we have gone over a time or two.
OnTheGo is offline   Reply With Quote
Old 12-20-2013, 06:22 PM   #8
Senior Member
 
Join Date: May 2013
Location: Dale Hollow Lake Tn/Ky
Posts: 1,944
As a general rule, doesn't it make sense to swap out all the batteries at the same time? That way the batteries should begin to fail at about the same time baring a quality problem with one of the batteries. Long term the $$ is the same, and it gives you confidence knowing that the battery pack has been upgraded rather than just one of two.

I have used the 6 volt golf cart batteries in both my TT and houseboat. I plan on upgrading the 12v that came with my whitehawk with 2 6v's in the Spring. Will be plugged in on our trip south in about a month so the single 12v should handle the road trip down and back.
Bassdogs is offline   Reply With Quote
Old 12-20-2013, 08:09 PM   #9
Senior Member
 
Join Date: Jul 2011
Location: Albuquerque
Posts: 261
This is interesting. Makes me feel bad for asking Costco to replace both of the 12V in my Ram when one battery lost a cell at 18months old. (BTW, Costco rocks.....18 months into those batteries they replaced both with no charge.)

I use 2x6V on the trailer so will be stuck when one fails. Oh well, worth it for the capacity vs space on my trailer!

-Chak
__________________
- 2005 Dodge 2500 CTD 6spd manual
- 2010 Starcraft Autumn Ridge 246RKS
- 2003 Casita Spirit Deluxe (sold)

My Write-up on managing 12V and batteries
LED Bulbs and what I did
Chakara is offline   Reply With Quote
Old 12-21-2013, 09:21 AM   #10
Senior Member
 
robkelly's Avatar
 
Join Date: Nov 2013
Location: Duxbury
Posts: 4,521
Thanks for sharing! Especially good for a newbie...
__________________

__________________
Rob & Kelly, Bella & Brady (Miniature Schnauzers)
2018 Pinnacle 36KPTS
2017 RAM 3500 SRW CTD/AISIN CC LB
robkelly is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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


» Virginia State Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -6. The time now is 01:14 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2002-2016 Social Knowledge, LLC All Rights Reserved.