Battery Question

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Doc

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Oct 5, 2007
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Is it possible to show good voltage at the battery with the charger off and still not have enough cranking amps?

I am still messing with my bow thruster. I got a new joystick which works but now the thruster will only run for a minute without running the battery down.

The battery is 6 years old but is a Lifeline 8D AGM that does nothing but lay there until I need the truster or windlass. It has not had very much use in its lifetime. We don't anchor but we do thrust occasionally.
 
Absolutely. Let the battery sit for a while off charge before you read the voltage. Take a reading while it is under load.
 
That particular battery is not cheap.....jus sayin'!!!
 
I have one more test to do and here is why.

I have been messing with the thruster for a couple of weeks. At dockside it only gets an echo charge. It takes this trickle charger a long time to top off an 8D. Sometimes 40-50 hours if it is really run down...according to a boat electrician that I spoke to. He said: "When the thruster is normally used, the engine is running, thus putting a good charge into the battery and keeping it topped off. When the engine is turned off, the thruster battery has done its job and gets only the trickle from the echo charger to maintain a full charge."

He also said that a 6 year old AGM is past it's prime, but not necessarily bad.

The test is to take the boat out and run it long enough to get the battery restored to full charge and then see how long the truster will run.

That is the current plan.
 
Doc -- It would seem that your shore power charger should*keep the AGM topped off. If not, you have either a battery or charger issue to deal with. Sometimes when leaving the dock, a thruster is necessary (not for a minute though) so having the battery charged up at the dock is important.

Did you do the load test RickB suggested? Is this a new problem or one that has been there for a few years?
 
It failed the test so it is coming out. I just got back from an spin in the harbor that lasted over an hour. The battery never did take a charge above what it had at the dock. My other batteries got up to normal running voltage.

Now I have to find two straping young men to pull it out of the hole and drop in the new one. 161 pounds. In the community where I live finding someone under 65 is tough.

Sunchaser: it is a new problem that began when the thruster started failing a couple of weeks ago.
 
Harbor Freight has a battery load tester for $19.95. Not a sophisticated instrument, but it will test a battery at rest and under load.

This is far easier than taking a battery to a battery retailer to have it tested.

I just replaced four house batteries and the charger. I'll never know if the charger failed and killed the batteries or the other way around. Of course, the replacemenrtt batteries had the terminals reversed from the originals so that required some modifications to the wiring, but why not - it's a boat!.
 
Doc, This depends on your charging system unless I am missing something. If your alternator is charging the house bank only and the echo charger is still charging the thruster battery while under way, then nothing is going to change from charging at the dock. The little secret that very few AGM manufacturers tell you is that if you do not recharge an AGM to 100% every time you go through a discharge/ recharge cycle, you will reduce the life of the battery. AGMs do not last as long as well maintained wet cells, and I usually only recommend them for systems that have batteries stashed in locations that make checking battery water and refilled very difficult. Chuck
 
Capt Chuck,

The echo charger is 110 volts. When I am running I normally do not run the generator so the battery is getting charged by the alternator.
 
Hi Chuck,

My experience with AGM's is somewhat different.* I do extended cruising and anchor 2/3-3/4 of the time. with no generator, and rarely bother to plug into shore power.* I use a Link 2000 battery monitor, so I have a good handle on how far my batteries get recharged (it's sure not always 100%) and how well they are performing.*

My house bank batteries, two G31 "dual-purpose" 12v AGM's (made by East Penn - Deka) are ten summers old and still going strong.* They've spent more than 600 nights at anchor so far.* Seems to me that with proper regulators and not much severe discharging abuse, these Deka AGM's can be expected to be very long-lasting.

The Optima AGM's which start my Cummins pickup (sitting outside in below-freezing temps much of the winter) are 9 years old and going strong.


Doc:* I would have no worries about replacing your 8D with multiple smaller batteries - 6V golf carts for example (and they're available in AGM as well).* Loads of cruisers have done this with great success - some banks as big as 8 or more 6V's.
 
I now have a new 8D AGM in hand and am waiting for two young constructions workers from down the street to show up.
 
RCook wrote:

Hi Chuck,

My experience with AGM's is somewhat different.* I do extended cruising and anchor 2/3-3/4 of the time. with no generator, and rarely bother to plug into shore power.* I use a Link 2000 battery monitor, so I have a good handle on how far my batteries get recharged (it's sure not always 100%) and how well they are performing.*

My house bank batteries, two G31 "dual-purpose" 12v AGM's (made by East Penn - Deka) are ten summers old and still going strong.* They've spent more than 600 nights at anchor so far.* Seems to me that with proper regulators and not much severe discharging abuse, these Deka AGM's can be expected to be very long-lasting.

The Optima AGM's which start my Cummins pickup (sitting outside in below-freezing temps much of the winter) are 9 years old and going strong.


*

Your experiences aside, this is a fact of life with AGMs and if ask directly the manufacturers will tell you the truth. You can also find it tucked away in some obscure part of their literature. Chuck
 
Captns Chuck and Cook, I think y'all are both correct. One is talking theory, the other reality. In theory, Chuck may be right. But in reality, wet cells likely don't get the exact care they need. So if you give each platform the same type of neglect, the AGMs are likely to outlast the wet cells when equally neglected....regardless of which is better when maintained perfectly. So since we all neglect our batteries to some degree, the AGMs are likely to outlast the wet cells...ANd as you pointed out Cook, they do!!!!
 
Wet Cells---Most common, flooded lead acid, low price, most
maintenance, use all same models-----4-8 years.

Gel---gel type electrolyte with silica added, no maintenance, less gassing,
No spillage---cons, kill easy, overcharge damage, much more expensive----
2-5 years.

Glass Matt or AGM, absorbent glass matt---Similar to wet cell---cons,
shorter lifespan, killed if overcharged, must recharge 100%-----4-7 years.
 
In my experience, AGMs last longer. They are just so damn expensive.
 
5 years since we finished Delfin's refit.* 1380 amps of Northstar AGM, and as far as I can tell, there is zero difference in performance between these batteries when new, and now.* I'm not sure what the theory is, but in practice in this installation AGM is performing better than any other battery I have had for a house bank including wet cells and gel.* I'll let you know in 5 more years how it's going.

I do acknowledge that you need more precise and accurate charging for AGM than wet cell, but that equipment is inexpensive and readily available.
 
Baker wrote:

In my experience, AGMs last longer. They are just so damn expensive.

I think most experts would side with you on this one.* I made the decision, based partly on the difficulty of checking the electrolyte levels, to replace my four house batteries with AGMs.* I also had to replace the charger which*had failed.

With the new AGMs in place, the*bow thruster runs faster than it ever did and theres at least a volt less voltage drop when the inverter is powering the microwave as indicated by the display on the inverter.*

ABM batteries are said to have a lower internal resistance.* My experience leads me to believe that this is true.

As for "expensive" I can't argue on that but if they save me the agravation of trying to check the electrolyte levels every month, provide better performance, and last longer, it's worth it.
 
AGM's last longer and are more expensive. Plus when they die, it is a sudden death. One minute it is faithfully on duty and the next minute it is toes up without even a faint moan.

I can now report that the construction workers did not show and I was miffed. Last night at happy hour at the yacht club (don't you know) a couple of members chastised me for wanting to hire it done. We can do it, they said. So this morning I called the most vocal one...69 years old... and he said WHAT? I said WHAT? Anyway he came over and this morning we pulled the old one from under the floor of the forward stateroom, up the stairs to the pilot house, down the stairs to the salon and out to the cockpit. The new one was then piss anted back the same way and dropped in the hole.

Each of us needed bandages to stop the bleeding (baby aspirin thins blood) but now the thruster runs like new. There is joy in the house.
 
Doc wrote:

AGM's last longer and are more expensive. Plus when they die, it is a sudden death. One minute it is faithfully on duty and the next minute it is toes up without even a faint moan.

I can now report that the construction workers did not show and I was miffed. Last night at happy hour at the yacht club (don't you know) a couple of members chastised me for wanting to hire it done. We can do it, they said. So this morning I called the most vocal one...69 years old... and he said WHAT? I said WHAT? Anyway he came over and this morning we pulled the old one from under the floor of the forward stateroom, up the stairs to the pilot house, down the stairs to the salon and out to the cockpit. The new one was then piss anted back the same way and dropped in the hole.

Each of us needed bandages to stop the bleeding (baby aspirin thins blood) but now the thruster runs like new. There is joy in the house.
Doc, was that at Isles YC?* We stayed there a couple of nights last spring.* Great club and food.* You will teach those guys not to talk too much around the YC bar.

*
 
Moonstruck, yes it was Isles YC. All hat and no cattle is the norm but a couple of guys stepped up and the battery is replaced. It is a great club but as chairman of the food and beverage committee I sometimes pull out the rest of my hair over the bonehead mistakes the kitchen can make. Things may be better since we fired the F&B Manager.
 
Doc wrote:

Moonstruck, yes it was Isles YC. All hat and no cattle is the norm but a couple of guys stepped up and the battery is replaced. It is a great club but as chairman of the food and beverage committee I sometimes pull out the rest of my hair over the bonehead mistakes the kitchen can make. Things may be better since we fired the F&B Manager.
Doc, we had two great meals there.* Lunch on Saturday, and the Sunday brunch.* The dock master and commodore were very nice in showing us around and making us feel at home.* After checking, the visit was Jan. '10.* Here is a picture of Moonstruck at the dock there.



*
 

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When I talked , years ago, to Mr Surette his method of extending the life of house batts was a slightly lower acid content (Specific Gravity) on initial fill.

Most were shipped dry then so it was easy if someone wanted extended life.

In my humble experience the best thing one can do for the batt set is a single solar panel 75-85W and a charge controller.

The longer the bat stays less than 100% charged the shorter the service life.

Solar is free , and DAILY!
 
Moonstruck wrote:

*
Doc wrote:

AGM's last longer and are more expensive. Plus when they die, it is a sudden death. One minute it is faithfully on duty and the next minute it is toes up without even a faint moan.


I had a flooded cell car battery do that recently so that's not exclusive of any particular battery technology.

Started the car up just fine, drove about fifteen minutes to the self service ice machine, shut it off for less than five minutes and it wouldn't start the car.* Not even a click.* Couldn't even jump start it, they had to tow it home and I went and got a replacement.

*
 
No-one's mentioned Gels.*

Ours are*coming up to*17 years old (made in 1994) and according to my state of charge meter and charging time, as good as new. They were "recondioned" or desulfated in 2004.

I know they are expensive, I was lucky enough to get them second-hand, but being absolutely maintenance free and having a system that sits at around 26V (24V design) is just great. Bright lights, excellent refrigeration,*powerful toilet, everything just works better.
 
FF wrote:

When I talked , years ago, to Mr Surette his method of extending the life of house batts was a slightly lower acid content (Specific Gravity) on initial fill.

Most were shipped dry then so it was easy if someone wanted extended life.

In my humble experience the best thing one can do for the batt set is a single solar panel 75-85W and a charge controller.

The longer the bat stays less than 100% charged the shorter the service life.

Solar is free , and DAILY!
FF, i was wondering if you would be able to show your solar panel set up.
possible with some photos showing the mounting etc.
thanks

*
 
I will post it , hopefully in a couple of weeks.

The Maineiacs that built the PH on LUCY used flat lumber , guess a band saw for a bit of camber would have taken higher skills.

Then the chopped a huge hole to R&R the engine, which was then boxed poorly.

So this winters task is a new PH roof , 2x as many overhead beams and a laminated covering.

AS Snowbirds the first item re mounted will be the solar panel as the boat sits sans a power hose for months.

photo will follow

-- Edited by FF on Thursday 17th of February 2011 05:48:12 AM
 
I have a highly related question. I have 2 GR27 Lifeline AGM house batts and had the same on my previous boat. As I recall on my last boat I could leave the boat for a month and when I'd return the batts would be at 12.75v or so but w the same batts in Willy they drop down to less than 12.6v in a few days. Don't seem to last very well at anchor as well. When we left the boat for winter work on the refit in the yard I told them what batts I wanted. When we came back in the spring I found they had got the new batts right away and they had been sitting on the shop floor all winter without charging. I suspect the batts were half ruined and I think their performance is half baked. I'm about ready to spring for 2 new batts but since it's a big sack of quarters I decided to pass it over the experts first. What think?
 
Eric, you might call Boat Electric in Seattle for a more expert opinion.* Depending on who you talk to, they can be well informed.* My understanding of AGM is that they can sit for quite a while without harm.* I can't find the spec now, but I think it is quite a few months.

AGMs are great, in my opinion, but seem to be more sensitive to charging variations.* Is is possible your current set haven't received optimum charging?
 
Hi Del,
Thank you ...I forgot to ask about Boat Electric. I couldn't remember the name either. They are on Westlake are'nt they? I will call them tomorrow as I know they know all that stuff. That's one of the reasons I spent the bucks and got the AGMs in the first place but the main reason is their rep for doing deep discharge regularly. Must be spring down there as I remember the cheery blossoms on the UW campus on Valentines day. Snowing hard here this morning** ..very white and grey. I see there's still plenty of snow down south too. Thanks Carl.
 
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