Battery or electric system problem?

[ejryan]

I checked voltage of both batteries upon arriving at the boat and both were fine.  Switched to cranking battery and attempted to start engine M25XP -- glow plugs for 30 sec, then start -- nothing happened!!  Tried again -- same results, except the second time, the low oil pressure alarm didn't even come on. Switched to house battery and engine started right away.

Disconnected the starting battery.  Checked the water levels -- all ok. Checked the voltage at the terminals -- about 5 volts.  The battery is at least 3 years old.

Can a battery fail without warning?  I thought I'd get a hydrometer and check the individual cells of the battery to see what that indicates.

Should I do some trouble shooting on the electric system before installing a new battery?  (Don't want to ruin a new batt if something's wrong.)  If troubleshooting, where to start?

Ed Ryan

[Jeff "salty dog" #1102 19]

Ed,
Agree you should check individual cell specific gravity with a hydrometer. Bet you'll find at least one cell bad. Yes, batteries do fail as you described.

Jeff

[Stu Jackson]

Ed

Jeff's right.  Also, what charger do you have?  That could also be a cause of a problem with your batteries.   A FIND on chargers on the message board will give you lots of input.

Try:

http://c34.infopop.cc/6/ubb.x?a=srch&s=329609511&findw=chargers

Link out dated doesn't work, sorry...  Stu  7/18/2010

Stu

[ejryan]

Stu,

The charger that I have is a Ray Jefferson that was on the boat when I purchased it in 2001.  (Have not heard that brand mentioned on any posts thus far.)  Although its manual calls it "automatic", the PO operated it behind a timer, so that it would only come on for about 1-2 hours every day.  I have a group 27 deep cycle, and a starting battery, and no major power users (i.e. no refrigeration, no major electronics, etc.) Since I have to motor about 30-45 minutes both leaving and returning from the marina, I have discontinued the use of the timer and basically don't use the charger on a regular basis.  The alternator is what came on the M25XP in 1989.

Any input on whether I need to change my ways (and/or the charger) would be appreciated.  Thanks to you and others for the info thus far.

Ed.

[Stu Jackson]

CHARGERS

Ed

Anytime someone says: "I put it on a timer," is a giveaway.

Ray Jeff's are SOOOO old and bad that I guess we just missed covering them.  I thought everybody'd thrown those overboard by now.

Sometimes the local dealers put the chargers on the boats.

Just a joke that Catalina "improved" things by putting just as bad chargers on at the factory.

Best bet, for starters (no pun intended) is to read the referenced link further above in this thread.

Second is to understand how alternators work, so try a FIND on alternators.  Unless you have an externally regulated alternator, it'll be just as bad for your battery charging as your Ray Jeff.  Tapering chargers do nothing worthwhile to charge batteries.  That's what alternators with internal regulators do, they're just like automotive alternators, not fit for a sailboat, even if you do motor 30-45 minutes.

With only 2 batteries, one house, one starter, I am sure, from even the basics of your use, that you're short one battery.  I would urge you to reconsider your house bank size, and install two house batteries or one larger one.  I've discussed this before, so try Catalina34 Electrical Systems as a FIND, also.  A basic boat needs 200 ah in the house bank.  Hard to do that in one battery.

By using one tiny battery for a house bank, you are assured of discharging it too far too often, and thus shortening its life expectancy dramatically.

This may be heresey, but:  ANYONE WITH ONLY ONE 100 AH HOUSE BANK, REGARDLESS OF THEIR boat's USE (even plugged into shorepower all the time) is SERIOUSLY SHORT OF BASIC BATTERY CAPACITY FOR EVEN A TWO HOUR DAYSAIL (unless - or even if - you have no stereos, instruments, fridge or lights).

(OK, OK, just to get a rise......)

Stu

[John Gardner]

Here's quite a good link to brush up on batteries.

http://www.4unique.com/battery/battery_tutorial.htm

John Gardner, Severn River, Chesapeake Bay.

[reedbr]

I have a counter opinion.  KISS, keep it simple.  I grew up sailing a Sabre 34 with two group 27's and no fridge or pressure water we never got stranded.  I used a single 27 on my previous Catalina 27.  Two group 27's and an alternator seems fine without major systems and managed usage. If you start chewing up batteries in less than three years or get left flat more than once, consider upgrading to 4D's.  However, they are much more expensive and bigger battery banks need charging system upgrades which then require wiring upgrades, switches, full time dock connections, etc.  Avoid the complications if you can, bigger isn't always better.  Monitor battery voltage during the year to make sure the alternator is fully recharging the batteries.  You can even check per cell with a baster.  However, three years of battery life is perfectly acceptable, and if you got five you would be lucky.  Calculate the cost of upgrading all the electrical systems versus getting one less year of life from your batteries.  Average group 27's are $75-$85/ea.  You could replace several sets before you hit the cost of electrical system upgrades.  And it is a sailboat, if you get stuck you're not completely dead in the water.  

Anyway, you all have great recommendations for building an excellent heavy duty electrical system.  However, consider the application first and determine if it is necessary.  Maybe I'm a minimalist, but it's a relatively cheap experiment.    

And to repeat what someone else already confirmed, yes batteries can fail like that.

Brian Reed
1997 C34 mkII "Ambitious"
Solomons, MD

[Norris Johnson]

I have a little experience here. Three yrs ago  I cooked my first set of 4D's with a FlyBack 20 charger. Bought 4 golf cart batteries (Interstate) and sent my FlyBack 20 back to the factory. The overhauled Flyback has been doing good and the golf cart batteries are great. My next project is a designated starter battery.

[Stu Jackson]

C34 Electrical Systems

Brian wrote:  "However, they [larger batteries] are much more expensive and bigger battery banks need charging system upgrades which then require wiring upgrades, switches, full time dock connections, etc. Avoid the complications if you can, bigger isn't always better."

I agree that bigger isn't always better.  But bigger battery banks do not necessarily require charging system upgrades, full time dock connections or bigger wires.

As I noted in the referenced discussion, Batteries and the Fridge:

(http://c34.infopop.cc/6/ubb.x?a=tpc&s=329609511&f=829605811&m=433600922&r=532609732#532609732

a larger battery bank will extend your battery life without having to upgrade the charger or wires, or having to resort to full time connection.  You already HAVE the switch.

That's why I said I recommend at least two house batteries.  The batteries will last longer, given the same discharge between charges.

If you use 30 amp hours a day, and have a 100 amp hour house bank, you're using 30% of the capacity.  With two 100 ah batteries, you're only using 15% of the bank.  The charging time is exactly the same, you don't need to plug in any longer, and the wiring doesn't change.  It's only one more battery, and complies with the KISS concept, without upgrading anything.

In lieu of going to 4Ds which are heavy and a bear to deal with, just another G27 in the house bank would do it.

Of course, if weight is an issue, the lighter the better.  The best solution I've seen for this is four golf cart batteries in the regular position, using two for one bank and two for the other bank.  I'm not a proponent of dual house banks, but for light weight and racing, it just can't be beat.

Cruisers and on-the-hook folks would be better off with a separate dedicated starting battery and as large a house bank as you can handle and/or need based on an energy budget.

With Brian's light electrical loads, a single house battery would suffice based on his enegy budget, but two batteries in the house bank would last much longer and also give some leeway to stay out longer without recharging if you wanted to or needed to.

Anyway, Ed, hope you found the cause of the problem.

Stu

[Ron Bukowski]

I've been following this discussion with much interest since I would like to upgrade my electrical system. I've looked at the information here and also in the WM catalog section on batteries. A diagram in the WM catalog shows two battery banks connected with a battery combiner so that one alt. output charges both banks. I can't find any info regarding a battery charger. How would that be wired into the circuit? Would one use a charger with a single output or would it take a charger with two outputs each tied to one of the battery banks? Would it make a difference if the ah rating of each bank is significantly different? My house bank consists of two 12v batteries in parallel for an ah rating of approx. 200ah.

[Ted Pounds]

Ron,

I think most of the good chargers have multiple outputs. My Statpower has three charging outputs.  You want to keep the batteries isolated when not in use so that if one fails (like in Ed's case) it won't kill the other one.  Imagine what would happen if a battery reading 5 volts accross the terminals was connected in parallel with a good battery.  :eek:   Of course that can happen while you're using them in parallel, but at least then you're on the boat to monitor the situation.  If your charger only has one output it's probably too old, will kill your batteries, and should be replaced.  

Ted

[Ron Bukowski]

Hi Ted,
Thanks for the reply but now I have more questions. A battery combiner is recommended between battery banks (house bank and starting bank) so that they are isolated during use but they will all charge from the same source. Are you suggesting the use of a battery combiner between batteries in the same bank? If two batteries are wired in parallel for a house bank are you saying that each one should have a seperate charging source (charger output)? I thought that batteries in parallel are treated as one larger capacity battery. Rephrasing my original question, if one alternater output can charge all of a boats batteries thru the use of a combiner, can't one charger output do likewise? If two seperate charger outputs are used how is the circuit effected, given that there is a combiner in it? One other thing, a charger with a single output is less expensive than one with multiple outputs.

[Stu Jackson]

C34 Electrical Systems

Ron

A battery cmbiner is a simple relay.  It is used to connect two battery banks (house and starting) automatically whenever a charging source is present (charger, alternator, solar, etc.)  It avoids having to use the 1-2-B switch to do that.

Many chargers have dual outputs.  Our Heart 1500 Freedom Inverter/Charger only has one output.  It was made before they modified it and built in an echo charger.  An echo charger is almost like a combiner functionally.  What it does is simply take about a 15A charge from the inverter charger and send it directly to the starting bank, while the rest of the charge goes to the house bank.

The advantage of the combiner is that it can use single point outputs to charge both banks, like your alternator and a solar panel.

Your choices:

1.  A good three stage charger with multiple (2 outputs) - one goes to the house bank, the other to the starting battery.  When you're on shorepower both banks gets charged.  Your alternator should be run to the battery switch so you can at least switch alternator output to the start battery when you chose to.  Remember, start batteries rarely need a lot of charge because they only take 2 amp hours to start your batteries.  If you're at marinas and plugged in a lot, you really don't need to bother with wiring the alternator output to the switch, just to the house bank, unless you plan to go out on the hook, in which case you wouldn't hav a way to charge the start battery.  No combiner needed.  NOTE: 7/18/2010:  Better yet, get the charging sources OFF your 1-2-B switch and to the house bank directly.  Do a search on "wiring diagrams" and find the "Best or Simple Wiring Diagram" thread.

OK, here it is: http://c34.org/bbs/index.php/topic,4949.0.html

The "infopop" links do not work anymore --- that was our way old software for this Message Board.  Thanks for understanding.

2.  Combiner layout: if you have a single output charger, OR a single output inverter charger, a combiner is useful so you don't have to use the switch to switch between charging sources.  This is what we have.  A downside is that there is the possibility of overcharging the starting battery because the combiner parallels the charge to both banks and the start baterry usually is always full.  ALWAYS wire the charge to the house bank, NOT the start bank, so the combiner only sends a smaller amount of power to the start battery.  

3.  Echo charge:  same deal as the combiner.  With a single output charger, you get a standalone echo charge unit and it draws a limited amount of charge to the start bank.  If you get a newer inverter charger it will have an echo charger built in.

This was previously discussed in great detail in the following message board reference:

http://c34.infopop.cc/6/ubb.x?a=tpc&s=329609511&f=829605811&m=654602911&r=574602911#574602911

I also suggest you do a series of FINDs using electrical, cobminer, echo charge, etc.: be creative - there are lots of discussions that relate to your question.

Also:

Are you suggesting the use of a battery combiner between batteries in the same bank?

NO, you don't need to do that.

If two batteries are wired in parallel for a house bank are you saying that each one should have a seperate charging source (charger output)? I thought that batteries in parallel are treated as one larger capacity battery.

YES you're right.  Once in a bank, it's one battery.

Rephrasing my original question, if one alternater output can charge all of a boats batteries thru the use of a combiner, can't one charger output do likewise?

YES, it can.

If two seperate charger outputs are used how is the circuit effected, given that there is a combiner in it?

If that's the case you do not need a combiner for shorepower charging.  The difficulty you face is what to do with the single alternator output.  But you could just use one output and a combiner, and wire all your single output charging sources to the hosue bank with a combiner to the start battery.

Have I mentioned Calder's book yet?


Stu

[tandm]

As Ted pointed out, most good chargers have multiple outputs and yes they cost more. But their cost is because they are good, not because they have multiple outputs.  Good chargers are "smart" in that they are computer controlled. This allows the charger to charge batteries in a way the produces the greatest AH while minimizing the untoward side effects that reduce battery life.  These chargers factor things like temperature, depth of discharge and battery capacity when determining the voltage and amperage to be applied to the battery at each stage of the charging process.  The reason good chargers have multi bank capability is that banks are seldom discharged to the same depth and often have different capacities.  

A battery combiner/isolator usually sits between the alternator/regulator and the battery banks.   A multiple output charger sits on the battery side of the combiner/isolator circuit so it has minimal effect on the rest of the charging system.

Many do not motor nearly long enough to fully charge the their battery banks so most of the work is done at dock side by the AC charger.  For these folks a good charger is well worth the extra expense. Also, if a "smart" charger is left on all the time, it will maintain the batteries without causing damage and extend battery life by keeping the banks fully charged.

td

[Ron Bukowski]

Thanks Stu and TD and Ted. I am beginning to piece everything together to come up with a plan. Stu, I have Calder's book and it has given me some info but not all I wanted. For instance, he discusses charging with a single alternater output and even two alternaters but he doesn't cover much about how to add an AC charger in the circuit. With a little more digging I'll figure it out. To me, and I'm sure to many others, this is the most challanging aspect of boat maintenance.