what voltage should a fully charged battery read?

(chaser) · (chaser) **Join Date: Sep 2006** 04-23-2009, 10:43 AM

After putting my battery on the charger for a cycle, I test it with the meter and it reads like 12.56 volts. Is this seem about right? I thought I read somewhere that it actually should be a little higher than that? My battery is 3 years old, just wondering if I should replace it or try to squeeze one more summer out of it.

(rallyart) · (rallyart) **Join Date: Nov 2006** 04-23-2009, 10:54 AM

12.6V to 12.8V is normal full voltage. The charge might be 13.3 just after you take off the charger but it will drop back to the real full voltage over a few hours.
You can get a load test done to see it's condition better than just the voltage. Your voltage seems fine. A battery will normally last 3-5 years. Some last 8 or more, and it's not always related to the warranty time or price you paid.

(acurtis_ttu) · (acurtis_ttu) **Join Date: May 2004** 04-23-2009, 10:59 AM

Voltage State of Charge
12.6+ 100%
12.5 90%
12.42 80%
12.32 70%
12.20 60%
12.06 50%
11.9 40%
11.75 30%
11.58 20%
11.31 10%
10.5 0%

Dont' go below 40% charge

(ottog1979) · (ottog1979) **Join Date: Apr 2007** 04-23-2009, 11:26 AM

This might be a dumb question. Will those low voltage trickle chargers extend the life of the battery? I'm thinking about between boating outings when it's just sitting in the garage.

I've had one on a car used very intermittently before, at my parents out-of-town condo. It did the job perfectly.

(Message edited by ottog1979 on April 23, 2009)

(acurtis_ttu) · (acurtis_ttu) **Join Date: May 2004** 04-23-2009, 11:32 AM

^^^ Yes, they will extend the life of a battery.

(guido) · (guido) **Join Date: Jul 2002** 04-23-2009, 12:33 PM

Andy... There is a company called Battery Tender that makes a maintainer/charger that works very well. They go one step beyond just keeping the charge. They also cycle on/off and provide a slight load. They help to keep the battery from getting sulfided.

Every vehicle that I have that sits for any period of time gets hooked up to a Tender.

(ottog1979) · (ottog1979) **Join Date: Apr 2007** 04-23-2009, 12:58 PM

Evan,

I'm checking that out (Battery Tender). Which model do you use? I'd prefer to have one attached to the battery case and stay in the boat - to be just plugged in when home.

(acurtis_ttu) · (acurtis_ttu) **Join Date: May 2004** 04-23-2009, 2:14 PM

I was referring to the battery tender as well. Mine is hardwired into the boat and stays in the boat. I just plug it in when I get back to the dock. I have the 1.5 amp one I think?

(brucemac) · (brucemac) **Join Date: Dec 2005** 04-23-2009, 2:41 PM

the multi-bank battery tender has quick disconnects that fit over your smaller ring terminals. they're nice if you don't have the room to mount it (i didn't) and they're just long enough to hang down just outside the battery box. they even have little rubber caps to protect against a short. my only complaint is mine is only like 1.5 amp output i think. takes a bit to fully recharge a drained battery.

(bill_airjunky) · (bill_airjunky) **Join Date: Apr 2002** 04-24-2009, 9:13 PM

Just checked the voltage on my two batteries. The POS Nautilus, which is probably the original battery in this 05 Vride, has 12.5 volts.

And the "good" battery, an Optima blue top, is down to 11.3.

I pulled the Optima & have it on a charger. We'll see if it recovers.