Battery life and charging.

All

Having read all the threads on battery life can I assume the following:

1. I should not discharge my batteries below 50%-ever?

2. May I assume, since my boat sits in a slip attached to shore power, that the constant trickle charge will not reduce the effective life?

My quest continues to be bringing my AC DC refrigerator up to maximum efficiency. I'm planning to replace my batteries with two type 27 115 amp units. Need to enlarge my stock battery pan to accomodate the larger batteries (i've been running with type 24 from Costco and replacing them each year-great warranty and price.)

John

John, others may know better and will also answer your question, but in the meantime, my understanding is that 1) you should never discharge your battery below 50%, and preferably not as low as that even. It's best to keep it charged as much as possible. 2) the trickle charge should help to keep it charged well, and should not in any way shorten the battery life. The only caution is that in some marinas, if there is stray current, you being plugged into shorepower 24/7 could increase the electrolysis/corrosion on your zincs. For that reason, I only plug my shorepower in a few days a month to recharge the batteries, or if I have been using accessories, to ensure they don't get discharged too low before re-charging.
Hope that helps. Let's see what others say as well.
Frank.

I'd agree with both points, provided that the batteries aren't being over charged or boiled (which shouldn't be an issue unless your charger is misbehaving or set up incorrectly).

Are you replacing your batteries annually because they're breaking down and the warranty is replacing them? Or are you just replacing them on your own dollar?

Either way, batteries shouldn't need to be replaced more often than every 3-5 years or so.

Nate and Frank

Thanks for the input.

I intend to disconnect from shore power because my zincs are dissolving way too quickly. This I would not have thoght of without your wise input.


I'll try to only recharge my batteries before I go out-or at least I'll see how it goes. I'll try this for a while.

I've run my batteries way down when camping over at the islands. Probably 12 to 14 times a year.ecause of this I simply change these batteries out on my dime.

If I went crusing I'd set myself up differently. For my purpose I want to get as much time as I can before I get down to the 50% level.

Nate, having been raised in Cape Elizabeth and sailed Casco Bay as I kid, sailing out here does not compare, but I get to go out all year and I for that I can put with Los Angeles.

Thanks again

John

Battery Life and Charging

If you are at a slip and recharge every night AND you have a real smart 2 or 3 stage charger, then 2-27's as a house bank are sufficient. Two 31's would fit in the same battery box and would be better. On the other hand, if you are away from recharging every night, such as anchoring out and only running the engine a couple of hours a day, then 2-27's are not even close to necc. capacity. When recharging with the engine alternator, you are effectively using the battery capacity between 50% (never go below) and at best 90% (since engine charging tapers rapidly as you approach full battery charge), or 40% of your total battery capacity. Therefore two 27's total 210 amps, gives you 84amps (maybe) usable in a 24 hour day with a about a 3 out of 24 hour charging cycle. Frig is about 4-6 amps per hour, times 24. Anyway, you get the picture. We used 2-31's for 5years but never went more than a couple of days before entering a slip for a complete 100% overnight charge with a 35 amp smart charger. You should also have a spare starting battery. Ernie Schlesinger ex E35-3 (now Sonar)

I disagree with the statement "..never go below 50%.."

You're correct however, to attempt to keep the level of discharge to a minimum in order to extend the useful life of your batteries. A few discharges below the 50% mark is going to make very little difference to the life of your batteries assuming that all the other components that make up your charging system are up to snuff. You should have an Alternator and regulator that match the size of your battery banks. The wiring must be proper marine grade tinned, stranded wire of an appropriate guage to your charging system and everything must be installed and fused appropriately. Keep in mind the voltage drops over long cable runs and for gosh sakes, get rid of that amps guage on your panel!

Nigel Calder's book is my bible for this stuff.....:nerd:

Batteries??

John,
Sounds like your battery setup may not have enough amps. You mentioned in your first post that you are going to enlarge your box to accomodate group 27 batteries. Is it possible to get two group 31 batteries in the space with modification? On to next question, if your having issues with not having enough amps, why not go with an externally regulated alternator of say sixty to eighty amps output and a Balmar or Ample power regulator. This will give you good charging while away from the dock and extend your battery life.
Now on to next issue; You stated that your zincs are going away quickly when plugged into shore power? This means one of your neighbors is dumping current to the shore ground most likely. Install a Guest galvanic isolator aboard the boat like a 2433P that meets ABYC standard, and your zincs should last longer. Good luck and enjoy the boat. Ryan

Having two small batteries and running a refrigeration system off them for more than a day will kill them very quickly. Even two group 31 batteries will only supply about 200 amp hours. I have three group 31's for the house bank and they are marginal for a weekend with the refrigeration running. I highly recommend reading this book http://www.amazon.com/Boatowners-Me...88/ref=pd_sim_b_1/002-3908362-6072018?ie=UTF8 It will answer all your questions and then some. You need at least 400 amp hours for a house bank. I am upgrading to 430 amp hours worth of 6 volt golf cart batteries next season.

The other issue is the refrigeration system. If its a converted ice box setup then again you need to read that section in the Calder book. Many refrigeration systems draw too many amp hours due to poor insulation of the ice box.

Or keep playing the change the battery game....

RT

Ryan

Heres my set up.

Stock 1973 E 35

Boat lived in a slip for 31 years-factory plastic on some of the cushions.

It had two type 24's. Has an old charge indicator guage Bad---Good.

Even older charger settings 1 thru 5, I have it set on 1.

I use no juice when anchored at Catalina. All lights are diodes. Don't use my old auto pilot. I only use my icebox with two Norcold plates.

Plates consume about 3 amps an hour. Box is insulated to ad nauseam. Still though at anchor I keep it on only 30 minutes every few hours. Don't need ice, but do need cold beer, Ouzo, Snappes, Limon etc

I do not charge the batteries by my A4. I did take a 800 watt generator last time. Drove me nuts.

What electrical guage do I need to ascertain my charge level. If I knew where I was at then I can choose a solar panel or wind generator.

What say you all.

John

desulfator

I've heard that battery life can be extended 3 - 5 fold by using a desulfator. Eliminates the lead sulfate buildup which apparently is the primary cause of battery death.

John, sounds like you are being quite economical in your power usage when away from the dock. To help your fridge, have you considered taking a solid block of ice along--if you have the room for it, it will displace some air in the fridge, generally keep it cooler, and further minimize the amount of time you need to run the fridge--and a block of ice at $2.00 each is pretty cheap. You could also economize further if you created your own by freezing drinking water in a plastic 4 litre jug, then using it for drinking water when it thaws--might even save on a beer or two.

If you plan on keeping the boat for a long time, you might consider installing a inverter/charger which also has a battery monitor/voltmetre on it--tells you how much you are using, how much is left, etc.

Frank.

Recomended setup

John,
From your description of the charger, I would guess you have a Lewco unit, which is ok for wet cell batteries. Go with two group 31 batteries if you can fit em in. I would definetly make the conversion on my alternator of that A4 to an external regulator that way you can charge your batteries from the engine very efficiently. Next I would not have solar panel any smaller than 100 watts. Try to look for a 3 stage solar regulator for the panel.
I would still put on the Galvanic isolator if you want to be safe from problems with the dock power eating your zincs. The problem is small amounts of DC current coming onto the boat from the green wire of the shore power. Galvanic isolator will block this. Sounds like you need to check out a Link 20 two battery monitor that will give you a digital readout on battery voltage, amps going into or out of the battery, and AMP hours (power remaining in battery). Ok thats my advice to ya. Ryan

Ryan

I'm going to go your route.

In an earlier post you mentioned an external regulator of 60-80 amps. Didn't mention a brand, but I can ask at WestMarine. Then I guess I need to couple that with a Balmer or Ample regulator to insure I don't cook the batteries. Am I right so far?

I do have a LEWCO.

I will install a galvanic isolator.

I think that if I can juice up my batteries with my A4 efficiently that will go a long way to help out. I'm one of those guys who loves the A4. It's efficient, effective and clean.

Thanks for your concern and wise advice.

John

You can make up for fairly low battery capacity by insuring that your refridge is well insulated...as has been pointed out.

It is also correct that the standard A-4 alternator (35A Delco) with it's internal regulator will not even begin to replace the energy drawn in any kind of reasonable time frame. The battery terminal voltage comes up rather quickly when charging and tells the regulator to shut down...way too prematurely. 35 amps, however, is more than enough to charge your house bank if you could force the charge over a more significant length of time. Also, although the alternator says it's rated at 35A output, getting even 30A out of it for more than a few minutes is a pipe dream.
Sea Quest has a switchable manual regulator with which I can control the charging current, usually 10-15 amps for as long as I want. I also use a battery isolator, diode type, to make sure both batteries charge.There is a danger that the batteries could fry...boil, actualy, if I forget to turn off the switch. With the boat at rest and the engine running, I can hear it lugging down as I crank up the load. Very neat.

I admit that I don't like to use the manual regulator...it's cool but I've never gotten comfortable with it.

As regards a galvanic isolator...get one and use it. They cost about $100 or less for a 30A unit on e-bay. Worth every penny.

howard keiper

Alternator

John,
No need for a new alternator, have your existing one reworked by a good shop to put out like sixty amps. Have the shop get rid of the internal regulator, bring a field and tach lead out for the external regulator to drive the alternator. I would highly recomend the Balmar MC 612 regulator as its easy to program and has better features in my opinion than the competition. If you use the Balmar unit, get the alternator and battery temp sensors. Good luck Ryan

Howard and Ryan

Tomorrow I'll start my research and put together my plan.

I'll post my progress.

Probably the most complex part of recreational sailing is electricity.

Thanks,

John

jkm,
While I agree with all the advice given here I don't agree with the necessity of all the upgrades. Since your boat is on a slip with shore power available the batteries can be charged easily from dockside power. It sounds like you really only use your boat for weekends and other short excursions.

Upgrading/increasing the size of your house battery bank will give the best bang for the buck. Do you motor much? Do you like having to run the motor to charge the batteries? A large battery bank will allow you to go much longer before needing to recharge. Let a battery charger take care of recharging when you get back to the dock.

I would recommend upgrading to at least 300Ah/hr house battery bank with a dedicated separate starting battery for the engine. Add to this a 40amp Xantrex battery charger with a galvanic isolator or better yet an isolation transformer. Solar panels, windchargers, high output alternators/regulators are great for putting energy back into a battery bank however they are not a crutch for an undersized house bank.

Things to do immediately:
Add more battery capacity, install galvanic isolator or isolation transformer, install high quality battery charger. This will fix your immediate problems

Things to add down the road:
Link 20 battery monitor or like, high output alternator/regulator, latching relay to automatically connect starting battery to house bank during charging.

Things to add if on a mooring or staying out for more than a few days:
Bigger house bank, high output alternator/regulator, solar panels and/or windcharger, Link 20 monitor.

It is very difficult to have to much battery capacity.
RT

Roer what Rob said.

The pecking order ought to put the galvanic isolator right up near the top.

howard Keiper

RW reply

RW,
Yes I agree that John needs more house bank and yeah two 31's is minimal in my opinion as well. Not sure how much room that John has for batteries or how much effort and cost he is going to put into the upgrades. My opinion would be that as long as the Lewco is opperating properly that he could use it and save the money for a battery monitor and or alternator upgrade. After all, more batteries are great, but how do you charge em away from the dock? Yes John needs to get the galvanic isolator ASAP and if possible get one that meets ABYC spec to monitor the neutral and ground. Ultimatly John will weigh all of our advice and decide what is best for his use of the boat and what his budget can afford. Ryan

Gents

I now know that i have a rather new Leece Neville Alternator part # 8MR2198L with a Leece Neville regulator part # 8RG2064.

Alternator puts out 65 amps, at what RPM I do not know.

I have room to modify my battery box to accept two type 27s-if the 31's are the same size, about 7" by 12" then I can jump up to the 31's.

Some where maybe I can put in a Type 24 for the motor start.

I've already gone to Ebay for the Galvanic isolator. None at this time but I will get one immediately.

I'll call a motor shop tomorrow to see if I can get rid of the regulator then investigate the battery monitor. I'll need something, maybe the monitor, to prevent the batteries from cooking. I'll report back as to how I can upgrade the output of the alternator, so that when I'm camping I can recharge, if I need to within a reasonable time.

I'll report back tomorrow.

Thanks so much I don't know how I'd get this done without you sages.

John