Recent Topics
Oil choices
by charmer37
07/22/18 07:22 PM
Lifeguard 8 and Audi 8hp55
by seanf
07/22/18 06:44 PM
2008 Tahoe loses power - electrical problem
by pacem
07/22/18 06:36 PM
How to clean wood trim?
by MajorCavalry
07/22/18 05:39 PM
Rotella T6 5w40 $12.97 after rebate
by dmiko
07/22/18 04:30 PM
Drivers not turning left with green light
by Mr Nice
07/22/18 04:25 PM
Someone hit my car
by Dylan1303
07/22/18 04:15 PM
Which spark plugs for 92 Olds 88?
by atikovi
07/22/18 02:54 PM
Electronic spark doesn't work on gas stove
by JLawrence08648
07/22/18 02:46 PM
Doorbell Button Bulb
by Yah-Tah-Hey
07/22/18 02:07 PM
AC/Blendoor Problem
by SilverFusion2010
07/22/18 01:53 PM
Suzuki 2.7L idle noise
by FlyPenFly
07/22/18 01:52 PM
TSC Rotella...YIKES!
by Greg L
07/22/18 01:48 PM
New Hampshire Speedway
by Warstud
07/22/18 01:13 PM
Tree growing from stump?
by edwardh1
07/22/18 01:02 PM
Kingquad hard shifting
by jay929
07/22/18 10:58 AM
CVT transmissions
by Gito
07/22/18 10:31 AM
sunday newspaper paper price increase $2 to $3
by edwardh1
07/22/18 10:08 AM
Tomatos and peppers
by Quattro Pete
07/22/18 10:02 AM
Homemade yogurt + probiotics
by onetwoothreee
07/22/18 09:16 AM
Newest Members
joonyflux, dippschtick, Brdftbll, NievesStefanor, Zervun
65529 Registered Users
Who's Online
79 registered (379KITTY, 2015_PSD, 10ecfarmer, 2002 Maxima SE, 12 invisible), 1598 Guests and 32 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
65529 Members
67 Forums
287488 Topics
4795820 Posts

Max Online: 3590 @ 01/24/17 08:07 PM
Donate to BITOG
Topic Options
#4608804 - 12/19/17 09:10 PM AGM Batteries 12.8 or 12.9v instead of 12.7 ??
LoneRanger Offline


Registered: 07/02/07
Posts: 4110
Loc: Midwest USA
"The sealed AGM and gel cell battery voltage (fully charged) will be slightly higher in the 12.8 to 12.9 range"
https://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html#3


I thought there was no diff between flooded wet cells and absorbed glass mat (AGM) on parked engine and parasitics off, charge shown on the multimeter.
_________________________

'09 Subaru Forester ...................(QS HM 5W30)
'16 Moto Guzzi Stelvio 1200 .....(ENI i-Ride PG 10W60)

Top
#4608819 - 12/19/17 09:21 PM Re: AGM Batteries 12.8 or 12.9v instead of 12.7 ?? [Re: LoneRanger]
bbhero Offline


Registered: 03/20/15
Posts: 4746
Loc: Virginia
Nah the AGM batteries will having a higher open voltage than a comparable flooded battery being both are truly 100% state of charge.



Edited by bbhero (12/19/17 09:22 PM)
_________________________
Nissan Altima 3.5 Coupe Formula Shell 5w30 Champion 7317
"Treat your family like your friends and treat your friends like your family."

Top
#4608822 - 12/19/17 09:22 PM Re: AGM Batteries 12.8 or 12.9v instead of 12.7 ?? [Re: LoneRanger]
Colt45ws Offline


Registered: 08/15/06
Posts: 9690
Loc: Central Washington
Yes, this is true, they have a higher OCV. They also prefer a higher charging voltage.
_________________________
-Colton
2002 Ford Crown Vic PI 207k, Ex-Kootenai County, ID Unit #42
Down for engine swap
2003 Ford Crown Vic PI 75k
Castrol EDGE HM 5W30, Fram XG2

Top
#4608957 - 12/20/17 05:07 AM Re: AGM Batteries 12.8 or 12.9v instead of 12.7 ?? [Re: LoneRanger]
Johnny2Bad Offline


Registered: 05/20/13
Posts: 1927
Loc: Saskatchewan, Canada
A fully charged lead-acid battery will show 2.2V per cell (6.6V on a "6 Volt" battery and 13.2V on a "12 Volt" battery).

The 12.7~9 V/AGM reading they refer to in the OP's article is after a load has drained part of the charge.
_________________________
'57 FL Straight 50 wt
'90 Miata 1.8L w/Rotrex Supercharger [Mobil1 0W-40]
'96 Ram 1500 [3.7L Mobil1 0W-20 / 1L 15W-50]
'01 PT Cruiser [Mobil1 0W-40]

Top
#4608995 - 12/20/17 06:07 AM Re: AGM Batteries 12.8 or 12.9v instead of 12.7 ?? [Re: LoneRanger]
LoneRanger Offline


Registered: 07/02/07
Posts: 4110
Loc: Midwest USA
Wouldn't 13.2v be the initial surface charge which bleeds off few minutes after removing a charger/maintainer, and the AGM battery then settles at 12.9?
_________________________

'09 Subaru Forester ...................(QS HM 5W30)
'16 Moto Guzzi Stelvio 1200 .....(ENI i-Ride PG 10W60)

Top
#4609179 - 12/20/17 09:50 AM Re: AGM Batteries 12.8 or 12.9v instead of 12.7 ?? [Re: LoneRanger]
maverickfhs Offline


Registered: 12/28/16
Posts: 2076
Loc: VA
Usually I have seen AGM stays between 12.75-13V. My current Yuasa AGM, stays at 13V even after a few days tender is removed, measuring from cheap HF multimeter though.

While lead acid ones I have seen between 12.4-12.6 after it has been fully charged, and tender is removed. These voltage varies based on the age of battery too.

All for motorcycles.
_________________________
2006 Civic EX 202K/AT
2006 Acura TSX 180K/AT

Top
#4609187 - 12/20/17 09:57 AM Re: AGM Batteries 12.8 or 12.9v instead of 12.7 ?? [Re: LoneRanger]
SHOZ Offline


Registered: 06/28/03
Posts: 5824
Loc: Illinois
The specific gravity of the electrolyte is higher in AGMs than a flooded battery. That is most of the gain in voltage.

Usually in the 1.315 range when finished and fully charged.
_________________________
2008 Hyundai Accent 1.6L 5 sp manual hatchback
2010 Hyundai Genesis Coupe Track 2L Turbo 6sp manual

Top
#4609233 - 12/20/17 11:05 AM Re: AGM Batteries 12.8 or 12.9v instead of 12.7 ?? [Re: LoneRanger]
PiperOne Offline


Registered: 10/25/17
Posts: 194
Loc: A Highway Near You
The AGM banks in our trucks when properly charged settle out at 12.8 to 12.9. We basically charge at 14.7 and float at 13.8 on the charger, alternators temp compensate and will run between 13.5 and 14.9.
_________________________
HDEO in Diesel Engines. No spark plugs here.

Top