battery voltage

[torcano]

The batteries on my boat both read 13.8 volts according my gauge. The batteries are 4 years old. My slip neighbor has a similiar boat and his guage reads 14.5 volts. How long do marine batteries usually last and at what voltage should they be changed? My boat turns over without any problem but I'd rather get new batteries than be stuck floating out at sea. The boat has an AC converter that charges the batteries when it is docked.
RK

 

[5150abf]

Re: battery voltage

13.8 is pretty good, they can last a long time if they are properly maintained, there really is no time when they go bad.
If your voltage is that high I wouldn't worry at all.

 

[lifeisfun]

Re: battery voltage

Yup, fully charged 12V battery should be about 12.7V
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%

 

[steelespike]

Re: battery voltage

Are those voltages while plugged in? It sure seems that way to me.
Plugged in voltage would depend on the chargers rate,batterys charge state,connectors condition any off condition load, radio backup memory etc.
What is your batterys voltage 1 hour and 24 hours after removed from charge?

 

[Gary H NC]

Re: battery voltage

13.8 is very good.it could be the difference in gauges between the 2 boats.
I would keep running them.

 

[torcano]

Re: battery voltage

steelespike, that was the reading while the boat with the dockside power on. I'll try checking it off the charger and see what readings I get. Thanks.

 

[dingbat]

Re: battery voltage

13.8 is pretty good, they can last a long time if they are properly maintained, there really is no time when they go bad.
If your voltage is that high I wouldn't worry at all.

A voltage test really tells you nothing. If you want to know the real condtion of your battery it needs to be load tested. A load test can tell you of an impending failure well before it actually occurs in most cases

 

[torcano]

Re: battery voltage

How do you do a load test? What type of equipment is required? I checked the batteries after being off the dockside power for 6 hours and the readings were 12.5 and 12.6 Volts.

 

[tashasdaddy]

Re: battery voltage

take batteries, to auto parts store, they test for free.