Go Back   Keystone RV Forums > Keystone Tech Forums > Technical Corner
Click Here to Login

Reply
 
Thread Tools Display Modes
 
Old 04-14-2019, 06:42 PM   #1
busterbrown
Senior Member
 
busterbrown's Avatar
 
Join Date: Feb 2016
Location: SE Michigan
Posts: 1,652
Dual 6 volt GC2 batteries and charging characteristics

We just returned home to Michigan from a 24 day trip around the southwest. This was the first big test of our dual 6 volt battery bank (upgraded from a single group 24 12 volt).

As I have really no experience with charging behaviors of a serial 6 volt setup, I'm looking to see if I need to upgrade the OEM converter charger on my coach. This is what I noticed during our trip.

1. Started with a fully charged 13.3 volt bank on the morning of our departure after plugged into shore power for 48 hours. The Duracell (215 amp hour) flooded batteries are brand new.

2. After using typical appliances through a dry camping night, (inverter with television, furnace, led lights, LPG fridge, and water pump), the bank would drop to 12.4 to 12.6 volts. We would run our 3700 watt inverter generator for 5 to 6 hours during the next day to allow the converter to recharge the bank. I thought it was preforming as expected except that the converter would charge to about 12.8 to 12.9 volts. I never got back to 13.3 volts until we plugged into shore power at a full hookup campground.

3. On several legs of the journey, we would leave the dry camp location wothout running the generator in the morning and drive 4 or 5 hours to our next camp site. I checked the volts on arrival at the new site and my TV would barely provide a recharge (12.5 to maybe 12.6). The previous group 24 12 volt would be completely charged after just a couple of hours of running the truck. (Obviously, I have much more amp hours with the GC2s).

My concerns are:

1. Is my OEm converter the bottleneck in my coach's recharging capabilities?
2. For a dual 6-volt in-series battery bank (flooded), what should I expect as a full charge? I've read 13.3 volts as being 100% as a float charge but absorption voltage could be much higher.
3. Will a true 4 stage converter charger (bulk, absorption, float, equalize) help maximize battery usability and increase overall battery life?
4. If a new converter is needed, what size (amp) is preferred? Are converter/inverter types recommended as I see the price point goes much higher? Realistically, I would like to see a full charge after a couple hours of generator use.
5. Is a larger battery bank crippled by the inadequate charging abilities of the TV?
__________________

__________________
2017 Keystone Bullet 308BHS in Saddle.
2017 RAM 2500 Laramie Mega Cab 4x4 Hemi 6.4L
2008 GMC Yukon XL Denali (SOLD)
Hensley SwiftArrow Control Hitch with 1000 lb Spring Bars
Me, DW, (3) little DS's, and 1 rambunctious Boston Terrier

busterbrown is offline   Reply With Quote
Old 10-16-2020, 12:23 PM   #2
Mogal
Junior Member
 
Join Date: Aug 2020
Location: Vancouver Island
Posts: 6
Sorry for the bump on this one, but I would have posted the exact same.

I just picked up a generator. its 2000/1600 watt.
When the genny is plugged in, the voltage get up to 13.3-13.5.
And I never seem to get a full charge.
I have two GC2 batteries with 230AH ratings (Total 460)

I'm considering buying this BLACK+DECKER BC25BD charger. It's a 25amp charger and wondering if it would make the charging a little quicker over using the built in charge coverter. The converter that came with the trailer is a smart 3 stage unit.

Thanks
__________________

__________________
TV: 2017 F-150 2.7 Eco with tow package.
RV: 2014 Bullet Premier 19FBPR
RV: 1996 Areolight 21RDS (Getting ready to sell)
Mogal is offline   Reply With Quote
Old 10-16-2020, 01:16 PM   #3
chuckster57
Site Team
 
chuckster57's Avatar
 
Join Date: Jul 2014
Location: Modesto
Posts: 12,201
I would stay with the stock converter.
__________________

2012 Copper Canyon 273FWRET being towed by a 1994 Ford F350 CC,LB,Dually diesel.
Airlift 5000 bags, Prodigy brake control, 5 gauges on the pillar.Used to tow a '97 Jayco 323RKS.

Now an RVIA registered tech. Retired from Law enforcement in 2008 after 25+ yrs.
chuckster57 is offline   Reply With Quote
Old 10-16-2020, 01:51 PM   #4
Canonman
Senior Member
 
Canonman's Avatar
 
Join Date: May 2016
Location: South Jordan, Utah
Posts: 1,420
Hi Mogal,
Just to be clear, 2, 6vdc batteries connected in series will provide 12vdc power output. The amp/hours of storage does not double.
How are you calculating when the batteries are at "full charge"?
13.2vdc is considered a "maintenance" charge from your converter. 13.6 is the normal charging voltage. 14.4 vdc is the bulk charge mode for recharging significantly discharged batteries. https://wfcoelectronics.com/wp-conte...eration-v2.pdf
__________________
2017 Cougar 279RKSWE
2007.5 Dodge Ram 2500 6.7 Cummins
Retirement Training Completed
Mr. Rodgers did not adequately prepare me
for the people in my neighborhood
Canonman is offline   Reply With Quote
Old 10-16-2020, 01:55 PM   #5
ChuckS
Senior Member
 
ChuckS's Avatar
 
Join Date: Mar 2014
Location: Mountain Home, Idaho
Posts: 1,358
For two GC2 batteries in series fully charged “Open” circuit will read 12.73 volts

Buying another converter or using an external battery charger will not yield any better results...

See battery charge table... from Trojan website...

The stock 3 stage WFCO will do as good as any regarding charge rate, charge times, etc... you won’t see over 12.7 volts when just in battery power

You will however see 13.4 to 13.8 when hooked to a 120 VAC source and converter is running.

The plates in the GC2 series battery are much more robust than typical flooded cell RV batteries
Attached Thumbnails
Click image for larger version

Name:	3B30ED3E-9366-4DA7-8434-A66C470C2A26.jpg
Views:	15
Size:	138.7 KB
ID:	30361  
__________________


2007 GMC Classic club cab 4x4 Duramax LBZ
2014 Alpine 3010 RE. 34 foot fifth wheel
ChuckS is offline   Reply With Quote
Old 10-16-2020, 02:03 PM   #6
ChuckS
Senior Member
 
ChuckS's Avatar
 
Join Date: Mar 2014
Location: Mountain Home, Idaho
Posts: 1,358
Also for me.. I use a specific gravity tester to determine my two GC2 batteries state of charge... quick, easy, and accurate
__________________


2007 GMC Classic club cab 4x4 Duramax LBZ
2014 Alpine 3010 RE. 34 foot fifth wheel
ChuckS is offline   Reply With Quote
Old 10-16-2020, 02:13 PM   #7
ChuckS
Senior Member
 
ChuckS's Avatar
 
Join Date: Mar 2014
Location: Mountain Home, Idaho
Posts: 1,358
OP... you might enjoy this read ....

http://oldschooltech.info/2016/11/of...ry-principles/
__________________

__________________


2007 GMC Classic club cab 4x4 Duramax LBZ
2014 Alpine 3010 RE. 34 foot fifth wheel
ChuckS 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
Forum Jump

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by the Keystone RV Company or any of its affiliates in any way. Keystone RV® is a registered trademark of the Keystone RV Company.


All times are GMT -8. The time now is 12:46 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×