Recent Topics
Unused Bosch 3313 cartridge
by Run
02/07/16 11:14 PM
David Fry in his own words
by Merkava_4
02/07/16 11:02 PM
Trans Pacific Partnership
by Merkava_4
02/07/16 09:57 PM
Schaeffer 711 10w30 Detroit 60 12.7
by TiredTrucker
02/07/16 09:17 PM
2012 Mazdaspeed3 transaxle 36k OCI 75W80
by MD1032
02/07/16 09:13 PM
Ford announces new assembly plant in Mexico.
by mrsilv04
02/07/16 09:10 PM
Guy with a cart full of Euro 5W40
by ledslinger
02/07/16 08:51 PM
Ever wonder how the new Camaro is made?
by BobsArmory
02/07/16 08:43 PM
Credit Card Reader 4 Smart Phone-Small Business
by crazyoildude
02/07/16 08:16 PM
talent doesn't pay like it used to.
by motor_oil_madman
02/07/16 07:46 PM
Disappointed with Accord after one Salt Exposure
by JHZR2
02/07/16 06:58 PM
Valvoline white bottle 2.99 at Menard's.
by jhellwig
02/07/16 06:47 PM
Newest Members
slewman, lithium1189, Monktana, djh3, Compignite
56850 Registered Users
Who's Online
62 registered (Astro14, Bandito440, ajchien, 15SilvyEcotec, 19jacobob93, 4 invisible), 846 Guests and 137 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
56850 Members
66 Forums
244397 Topics
3979501 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG
Topic Options
#1678999 - 11/20/09 05:41 PM How to read the meter on a battery charger
GhostFlame Offline


Registered: 07/15/09
Posts: 424
Loc: Doylestown, Pennsylvania
Forgive me if this has been discussed.

I have a 4amp 12.6 volt battery charger. No extra settings. the meter jumps to 6 amps when the battery is drained. it moves slowly left to the lower amperage numbers after a while of charging. from left to right the meter reads 1 2 3 4 5 6

When do I know the battery is fully charged? there is no volt meter on the charger.

I had my daughter's battery on the charger for about 16 hours after she left the lights on for like 2 days. the battery jumped to 6 and after about 2 hrs settled down to 4 but never went any lower. the car started but, I would like to know.

Would my handy volt meter be a better indicater? I think 12.6 or 13.2 is the magic number when it's fully charged.

Any help , thanks
_________________________
2002 BMW X5 3.0 M1 0w-40 trying RT6
1998 VW Jetta 2.0
2004 Honda 1800c V-Twin 110 ci M1 4t Racing 10w-40

Top
#1679005 - 11/20/09 05:46 PM Re: How to read the meter on a battery charger [Re: GhostFlame]
EricF Offline


Registered: 07/14/09
Posts: 1636
Loc: SF Bay Area
what happens is the meter shows the amount of amps being pulled.
so when the meter was at 6amps, the battery was drawing 6amps of power to recharge itself. after a while as the capacity gets fuller, it draws less amps, so now you're at your 4. when it gets to 1 or 2, you're at a trickle, and the battery is/should be/close to full capacity.

you have a slow charger, 6amps, so charing for 16hours is normal for an extremely drained battery.

the magic number for a charged battery voltage with no load is 12.3 - 12.5volts at rest.
_________________________
1993 Ford Ranger XLT 4.0L 4x4 (240k) 5W-30 Synpower
2006 Saturn Relay-3 3.5L (85k) 5W-30 Synpower
2012 Ford Fusion SE 2.5L (39k) 5W20 M/C Semi Syn

Top
#1679006 - 11/20/09 05:48 PM Re: How to read the meter on a battery charger [Re: EricF]
GhostFlame Offline


Registered: 07/15/09
Posts: 424
Loc: Doylestown, Pennsylvania
That was fast thanks!! very informative.
_________________________
2002 BMW X5 3.0 M1 0w-40 trying RT6
1998 VW Jetta 2.0
2004 Honda 1800c V-Twin 110 ci M1 4t Racing 10w-40

Top
#1679040 - 11/20/09 06:29 PM Re: How to read the meter on a battery charger [Re: GhostFlame]
Mr Nice Offline


Registered: 09/12/04
Posts: 15907
Loc: Orlando, FL
Eric,

what is the voltage of the battery when the engine is running ?

What is the range of voltage as the engine RPM increases to redline ?

Thanks
_________________________
2007 Civic EX
2006 Accord SE
2005 RSX base
2005 Civic LX

Top
#1679104 - 11/20/09 07:24 PM Re: How to read the meter on a battery charger [Re: EricF]
JHZR2 Offline



Registered: 12/14/02
Posts: 37303
Loc: New Jersey
Originally Posted By: EricF
what happens is the meter shows the amount of amps being pulled.
so when the meter was at 6amps, the battery was drawing 6amps of power to recharge itself. after a while as the capacity gets fuller, it draws less amps, so now you're at your 4. when it gets to 1 or 2, you're at a trickle, and the battery is/should be/close to full capacity.

you have a slow charger, 6amps, so charing for 16hours is normal for an extremely drained battery.

the magic number for a charged battery voltage with no load is 12.3 - 12.5volts at rest.


If your battery is 42Ah, and flat, it could take 7+ hours at 6A charge to go full. The rates do change, so in reality it takes a bit longer.

Two things though... First, the battery will charge at up to 14.1V - some may feed at a higher voltage. Even after it is full, the battery will have a "surface charge", which keeps it over 13V open-circuit.

Second, a full battery at normal temperature is roughly 12.72V at OCV.

Top