Battery Replacement

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_Ele ... arging.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
 
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
 
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.
 
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.
 
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.
 
Don and Brenda":3ads1odp said:
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.
Click to expand...

First idea: Can you rig a solar charger on top of the boat, building, or marina roof to charge the batteries?

Second idea: Long cold storage periods without charging will gradually kill any battery. If you can't charge them in the boat, can you take them out and take them home to keep them warm and charged?

Third Idea: Battery make is less important to me than size (24, 27, 31, etc.) AND battery care. I worry more about keeping them charged, dry, warm, de-sulfated, filled with water, etc..... than the brand. Just get big ones, take care of them, and be sure the selling agency does hassle-free pro-rated returns on their warrantees.

Joe. :teeth :thup
 
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....
 
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.
 
I am wondering why you are replacing the VHF and GPS if the boat is only 2 years old? I find that the 4 year old VHF radios and GPS/chart plotter work as well--as the new ones I just pruchased for the newer boat.

There are some other electronics--such as AIS, Broad Band Sonar, which may well be improvements over 2 year old technology. On the other hand, if you will be cruising in 3 to 4 years, then wait until just before you area ready to go before replacing any electroncis. There are some changes every year, and there may be some marked improvements in 4 years.
 
Good question Bob

Yes the electronics are only 2 years old. The existing VHF is a Humminbird, and in my plan for long distance cruising I relocated that radio to the far side of the overhead as a back up. Installed a new Uniden 525 as the primary. Previous owner already had 2 VHF antennas mounted so this will work well. Basically I am doing the redundency thing. Next weekend will be the install of shore power and battery charger. I need to slow down a bit as the wife keeps seeing $$$$ signs. The GPS is a Lowrance and that will also stay as the back-up. It will be a few years before I add a new unit and the radar. By then I figure the broadband will be much cheaper and I might have enough money saved to purchase a new unit.
 
Don,
Wise to wait on the broad band radar. I think that we will see all of that sorted out in a year or two, and perhaps Lowrance's factory response will be better when you have problems (I have Lowrance and have not had problems, but those who have, complain about customer service).

Also there are some exciting things in the fishfinder and side scan field--maybe even we will see some decent forward looking sonar, for less than $15,000.
 
Desolation Cruiser":1npabdgu said:
Jazzmanic

I work at the NAPA store in Powell River.
I thought I should let you know about the latest in battery testing and charging technology.
We recently purchased a battery tester that measures the useable surface area remaining on the lead plates inside a battery. As a battery detriorates the useable surface area of the plates decreases,(for various reasons) lowering both the batteries Cranking amp and storeage potential.
These testers are becoming common in the automotive and marine service and repair industry locally because they can accurately determine the "state of health" of a lead acid battery, either absorbed glass mat (AGM) or flooded cell.
A simple voltage reading can not tell you anything about the condition of the plates which will deteriorate very quickly after a certain point.(good one day and bad the next)
I believe the key to long battery life is an automatic charger (maintainer)
which will keep your batteries at the optimal voltage for storage.
Sulphation occurs on the plates when the battery is left in a discharged condition (below 12.4 volts)
A lot of batteries are replaced long before thier life has ended!
I hope this helps.
Nice to hear that you will be in the area this summer 8)
Click to expand...

Is this tester better than a load tester or a supplement?
 
Regarding the battery replacement topic, I favor plenty of large, deep cycle batteries as an alternative to 1.) starting or 2.) dual purpose batteries.

Depending on the twins/single choice, some boats commonly carry either

A.) one starting battery and one house (deep cycle) battery (single engine applications)

or

B.) two duel purpose batteries ( twin engine applications)

(Other combinations are possible, of course)

Instead of using the starting or dual purpose batteries, which have thinner plates and cannot be discharged as deeply or repetitively as deep cycle batteries, I favor using only deep cycle batteries, but adding a few more, such as going to four deep cycle batteries.

The four batteries never seem to run down (with a little judicious observation and supervision), and always have plenty of voltage to start a single or even two motors. The change from two to four batteries easily compensates for the difference in cell plate surface area when changing from starting or dual purpose type batteries to deep cycle ones, and the deep cycle ones last longer and are better suited for house use anyway.

The main disadvantages of the 4 battery system are the initial cost, the weight in the boat (efficiency), lost of storage space, and the cost of the initial wiring and switching set up.

I know there's another side to the story, but that's my simplistic approach, my story, and I'm stickin' to it!

(I've got four deep cycle group 27's with 460 amp hours in my CD-22, connected with two Off-1-both-2 switches, no relays, etc.)

Joe. :teeth :thup
 
A strike against Optima Blue Tops. Just bought a replacement Blue Top house battery less than a month ago, on the water with it once, on the 17th. Went out this morning to start getting ready for a CG Auxiliary patrol on Saturday. 3.5V !! It has been disconnected from the system (VSR switched off), no unusual connections, corrosion etc., Connected it to the smart charger, showed a failure reading for an internally shorted failed battery. Grr.
 
TRAILER BOATS magazine comes thru again. GREAT article and good read on batteries. May 2010 issue. www.trailerboats.com is their site.

WOW... deep cycle batteries with 200+ AH.... OMG!!! Couple of those puppies wired in parallel would be way sweet. (at about $413 for flooded cell & $886 AGM w/214 AH)... Ouch!! That is about $4.04 per AH. Maybe if space is way, way limited and demand is way way high between re-charge cycles.

Looks like a "LIFELINE" brand battery (never heard of them...??) has an AGM w/150 AH for $ 388... $2.59 per AH... Pair of them gives 300 AH for about $ 776 Still a bit of funds...

Now, for those who could frequently get access to their batteries, and do not mind the ol flooded cells.... and could give up down to a pair for 250 AH @ $150 (yes, for both of them)... brings it down to $ .60 per AH.... for a EverStart battery.

So... a good article.... and a spread of 60 cents per AH to $ 4.04 per AH. Man, having a nice battery box area with good clean easy access seems to pay off here.

Good read.
 
Patrick-

Since I don't plan to run my C-Dory upside down, do barrel rolls, loop-d-loops, or venture into nearby space, etc., I'm quite happy with the old flooded cell type deep cycle batteries,

4 group 27 Everstarts are indeed about $70-$75 apiece, and at 115 AH each, the total 460 AH for $300 or a little less does come out out to $0.60-$0.65 per AH, and running them down is pretty hard to do. In fact, I've never had them refuse to start the motor, period.

In batteries, the old, reliable, low-tech type solutions are much more reasonable, cost-wise, and with the continuing evolution of battery technology/chemistry, the simple, everyday, flooded cell, deep cycle marine batteries the best deal around, IMHO. (K.I.S.S., again!)

Joe. :teeth :thup
 
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