Battery Replacement

Desolation Cruiser · Posted: Wed Jun 24, 2009 4:35 pm Post subject:

Smitty
The key is regular testing of the internal condition of your batteries which as far as I know can only be accomplished by this type of tester.
Your batteries would have failed this type of a test.

Jazzmanic · Posted: Wed Jun 24, 2009 5:53 pm Post subject:

Thanks for the info Desolation Cruiser. Although I did end up purchasing new batteries, that type of tester would have come in handy. I have a feeling I replaced the cranking battery before I needed to. It would have been nice to confim that with the tester you're referring to.

Oh well, it's just more money going towards the boat... Crying or Very sad

Peter

Doryman · Posted: Wed Jun 24, 2009 10:43 pm Post subject:

Desolation Cruiser · Posted: Thu Jun 25, 2009 11:35 am Post subject:

Doryman

The unit we use here is manufactured by Midtronics
http://www.midtronics.com/home/products/transportation/batterytesters/batterytesters.aspx

It is the Micro 400 modelhttp://www.autoshoppingcenter.com/techtools/MIDTRONICS/Micro400.html

It performs a conductance test as described here http://www.batteryuniversity.com/parttwo-41.htm

hardee · Posted: Wed Jul 01, 2009 2:58 am Post subject: is that not a full charge?

So what is the "fully charged battery" voltage going to be at, and is there a range that goes up from a full charge to the maximum one could expect to have on a new, completely fully charged battery? Does this number vary according to the battery type, Flooded, AGM, or Gel? If I leave my batteries showing 12.75, is that not a full charge?, or should I be putting them on the charger even at that level?

Harvey
SleepyC

denny-o · Posted: Wed Jul 01, 2009 7:36 am Post subject:

Battery 100% charged voltage is roughly 12.65 volts (temperature dependent)
A 12.7 battery does not need charging...
A battery fresh off a charger will show a bit over 13 volts... This is a "surface charge" and is inaccurate.. Either put a load on the battery for a few minutes to bleed the surface charge, or let it set for an hour to equalize the surface charge...

Here is a good, with a bit of overkill, information spurce
http://www.arttec.net/Solar_Mower/4_Electrical/Battery%20Charging.pdf

Notice the Battery State Of Charge IN Percent graph...

Or here, a bit simplified (they know their customers)
http://www.xantrex.com/web/id/329/DocServe.aspx

hardee · Posted: Tue Jul 07, 2009 1:35 am Post subject: more accurate than I thought

Denny,

Thanks for the links, and the answer. That confirms the little graph I have with my Walmart Digital cigarette lighter plug volt meter. It seems it is more accurate than I thought.

Harvey
SleepyC

Papillon · Posted: Tue Jul 07, 2009 7:47 am Post subject:

Corrected Link from above:

http://www.autoshoppingcenter.com/techtools/MIDTRONICS/Micro400.html

hardee · Posted: Wed Jul 08, 2009 11:32 pm Post subject:

Thanks Mike, I only looked at the Xantrex one the other night. Good info.

Harvey
SleepyC

SENSEI · Posted: Mon Jul 13, 2009 8:01 pm Post subject:

I just installed two new group 27 deep cycle batteries on the 25 and am trying to figure out how big of a charger I should put into the mix. with an ACR between the batteries I only need a single bank charger but I want to put a big enough size to do a good job of charging and maintaining the batteries even in winter storage
so what recomendations might I get from ya'll.

thataway · Posted: Mon Jul 13, 2009 9:00 pm Post subject:

Normally I change the batteries every 4 years, but have had some last much longer. The current batteries on Frequent Sea, seem to be the 2003 group 24 which came with the boat. I don't know if they were taken home by the previous owner or not. I kept a solar charger on them when the boat was in storage, and they have been up to the task. I am going to replace the batteries (main and engine start--the deep cycle AGM for the refigrator are only 2 years old), for the new owner, even though the old ones are still "good".

I agree that sulfation is the death of batteries. I perfer to run a small charger on a timer a few hours a day, rather than float the batteries all of the time when on a charger. I try and never discharge the battery to less than 12.2 volts. There are "Pulse desulfators" which do seem to decrease sulfation--Battery minder is the brand I have used.

Don and Brenda · Posted: Fri Oct 30, 2009 5:27 pm Post subject:

Are all group 27 batteries about the same size. I would like to change out the 24's to 27's. I have twin motors with 1 battery starting each motor and also serving other electronics also. I have the standard lazzarette covers and unfortunately the boat is 50 miles from me to get some measurements off of. Thinking of going with Sears GRP 27's so hope they will fit. Any ideas? The boat sits in cold weather for longs perios with no way to keep a charger on them.

Sea Wolf · Posted: Sat Oct 31, 2009 12:03 am Post subject:

thataway · Posted: Sat Oct 31, 2009 5:34 pm Post subject:

The group (ie Group 27) refers to the case size. There are some minor variations, but if one group 27 will fit, then most all group 27's will fit. If you need a low self discharge battery, then consider AGM batteries. On the other hand, I do use a very small solar cell to keep the group 24 starting battery on my Road Trek RV charged. It has not been run in 8 months, and my son ran down there to move it today--fired right up (battery is disconnected from the leads to the RV--just hooked up to the solar charger. This battery is over 6 years old, and was of unknown condition when I pruchased the RV...I am sure that I will have to replace it in the next year or so, but....

Don and Brenda · Posted: Sat Oct 31, 2009 6:41 pm Post subject:

I purchased a group 27 today and will replace the group 24 next week. I like the idea of a solar charging unit and this may be the way I go. I hate replacing batteries every couple of years. When my other 24 goes out I will replace it with a 27 also. In a few years when I retire I will probably change out the whole system and use a starting battery and a set of house batteries. Right now I have started to replace the vhf radios, next will be the gps. The list is long, however I have about 3-4 years before I do inside passage cruising.