New Boat , Poor Battery Performance

[PhilDuhs]

Hello all,

I have taken delivery of a new boat about 2 weeks ago but am disappointed with the battery performance and am wondering if my expectations are too high or there is something wrong with the batteries and/or charging system.

The service battery bank consists of 4 x 140 Ah Tudor TE 1403 batteries which are probably cheapest of the cheap but I'm sure should be doing better than what they are. I am (reluctantly) prepared to replace them with something much better but would love to get some expert opinions first!

The main problem is the battery voltage dropping quite quickly to around 11.8V even after just being charged. Below are some readings that I took today that are pretty typical of what I have been finding over the last 2 weeks cruising:


TIME VOLT. LOAD CAP. NOTES
---- ----- ---- ---- -----
09:00 12.0V -1.0A 501Ah Only anchor light on (woke up late!)
09:05 11.9V -5.5A 501Ah Computer turned on
09:45 11.9V -4.6A 498Ah
10:00 11.9V -4.5A 496Ah
10:00 14.0V 72.0A 496Ah Genset on
10:10 14.0V 49.0A 504Ah
10:25 14.1V 33.0A 513Ah
10:30 13.1V 3.0A 517Ah
10:35 12.7V -18.6A 517Ah Battery charger off
10:35 14.1V 34.5A 517Ah Battery charger on again
10:40 14.1V 27.0A 520Ah
10:55 14.15V 22.0A 526Ah
11:05 14.2V 21.0A 529Ah
11:06 13.2V 3.0A 529Ah
11:07 12.8V -17.7A 528Ah Battery charger off
11:09 12.8V -13.4A 528Ah
11:10 12.9V -8.0A 528Ah
11:10 12.75V -12.3A 527Ah
11:10 12.5V -22.0A 527Ah Water pump in use
11:10 12.8V -6.5A 527Ah
11:15 12.5V -23.0A 526Ah Nav system + fridges
11:15 12.3V -40.0A 526Ah Nav + Fridges + Water pump
11:15 12.6V -12.0A 525Ah
11:15 12.5V -17.0A 524Ah
11:20 12.3V -30.0A 523Ah
11:30 12.3V -27.0A 522Ah
11:30 12.2V -33.0A 522Ah
11:30 12.4V -17.0A 522Ah
11:30 12.15V -34.0A 522Ah
11:30 12.3V -18.0A 522Ah
11:40 12.1V -30.0A 517Ah
11:40 12.3V -13.0A 516Ah
12:10 11.9V -18.0A 509Ah
12:10 11.8V -30.0A 509Ah
12:10 12.0V -14.0A 509Ah
12:40 11.8V -13.0A 502Ah
13:40 11.8V -6.5A 492Ah
13:45 11.8V -3.6A 492Ah
16:20 11.8V -3.6A 481Ah
21:00 11.7V -5.4A 471Ah

I hope this is self explanatory but I'm surprised by 2 things:

1. That the charger (2 x Dolphin 40A chargers from Reya International Cannes) drop back to a tickle mode (10:30) but if I turn them off and back on again they keep giving a good charge for some time more (10:35 -> 11:05).

2. That the voltage drops down to 11.8 quite easily and seems to stabilize there. Surely this should be something over 12v.

I am happy to do as much testing and provide any information that will be useful to diagnose what's wrong (or not) as I would like to know if I need to make any changes to the batteries or other systems aboard.

Rgds,
Phil

[Rick]

Your batteries are dying a slow death from "starvation". Your charge source(s) MUST reach a minimum of 14.4V in an acceptance mode (20 deg C). That voltage may be as high as 15V as long as the charge current does not exceed (for long periods of time) the number of Amp-hours missing from full capacity.

[zeehag]

how old are the batteries?????????
have you checked the war in them or are they the kind that ye dont have to do that with?? which means they die sooner....
did ye check sans anything hooked up?? didja wait a while to see where they settle down to when done charging or just keep em hooked to all the draining devices???
didja buy the boat brand new or just new to you, in which case, new batteries might just help you out a lil???/
AND what rick sed.

[s/v 'Faith']

Where exactly (and how) are you taking these voltage readings?

[sailorboy1]

What are you using to get the Ah on your post? If it's a monitor is it setup correctly? If it is a monitor what is it saying for state of charge?

Looking at the readings i seems you are taking a lot more amps out than what you put in. I wouldn't believe the higher voltage readings all that much right after you stopped the charge.

[Captain Bill]

These don't look like very sophisticated chargers, they may be sensing each others output and going into float prematurely. Do you have the proper mode selected? I didn't look up your batteries, but it looks like your voltages are set for sealed rather than flooded lead acid batteries. As rick said they should be getting to 14.4 before going into float. I'ld try charging on just one unit and see what happens. You might also be having an issue with the power factor when operating off of the genset, can you plug into shore power for at least a test? If you have the same problem with only one charger, try the shore power test and see if you still have the problem. If Shore power solves the problem you have a problem with power factor. There are a number of threads discussing genset power factor and charging issues so I won't get into the details here but it can be the source of many charging woes.

[S/V Illusion]

Far too many variables and unknowns to give sound advice. There is only one typical suggestion which is always correct - that being to thoroughly go through the wiring removing all connections for a proper cleaning. People spend an inordinate amount of time wasted trying to identify perceived problems only to find out the major problem is a bad connection. At worst, you will better understand the wiring and often spot other less obvious problems.

[donradcliffe]

The batteries are Indian truck starting batteries--truly the cheapest of the cheap. They will die pretty quickly, as they are not deep cycle and are not being fully recharged.

The boat sounds like a power hog. My anchor light, computer, and fridge each take 20% of the power yours do.

RTFM and see if you can get the chargers to run at 14.4 volts.

[PhilDuhs]

Thanks for the replies so far! I'll try to address some of the questions now, others might have to wait for another round of testing:

@Rick - the setting the battery chargers are set to (both the same setting) is for "Wet & Flooded Electrolyte Batteries" and has a charge characteristic as per the following:


...so it seems to be working towards 14.4 but cutting off early. I have asked the Dolphin charger manufacturers if Captain Bill's suggestion of the chargers sensing each other may be a factor.

@Zeehag - the batteries are 6 months old but have been on shorepower (actually plugged into the wall at the boat dealers) from January - June so should have been at 100% charge for that time (boat bought brand new). Water has been checked and was not low in any cells across all 4 batteries. Have not let them settle after charging - will do that (remove all load for approx. 8 hours after charging) in next few days and report back.

@s/v Faith & Don - voltage readings (and other readings) are being taken from a Philippe BCM II battery monitor that has been professionally installed. PDF here.

@Captain Bill - Proper mode is selected after checking with manufacturer a couple of days ago (was set to sealed lead acid, now to flooded lead acid). I will plug into shore power sometime in the next week and will make some more recordings then to see if charging pattern looks any different.

@S/V Illusion - there's a million connections but you're right, definitely worth checking. Will do.

@donradcliffe - agree 100% re the batteries, in fact that's what makes me tempted to replace them with something like Varta Professional Deep Cycle batteries. I'm in Croatia/Greece so finding common US brands mentioned on this site a lot can be difficult. AGM not for me I think as won't be charging to 100% very often and seems that's what AGM need. After a quick check it seems anchor light = 1A, computer = 3.5A, fridges = 2 x 6A, nav equip (all on during test to try to draw as much current as possible) = 12A, water pump running = 15A approx. You could be right and boat is a power hog but is what it is I think. I've space for more batteries and if I did replace Tudor's I'd go to about 1000Ah capacity.

Not sure if that gives anyone any more to go on but will definitely try to get higher voltages into the batteries. Thanks again.

[Jim Cate]

Since they are common flooded lead acid types, the obvious thing to do is use a hydrometer to measure the specific gravity of the electrolyte. This is a better means of determining state of charge than the terminal voltage or the unverified monitor.

Also, it might be good to use a multi meter to check that the monitor is accurately measuring the voltage (although it looks generally ok).

Also could be useful to isolate the batteries and check each individually... see if the voltage is down on all of them.

It must be pretty disappointing to have these issues with a new boat... my sympathy.

Cheers,

Jim

[MarkJ]

I don't think you are charging them enough.
At 11.9 volts your batteries are flat.

12.66 V = 100%
12.45 v = 75%
12.24 V = 50%
12.06 V = 25%
11.89 V = 0%

So to charge 400 amp hours of batteries at 40 amps per hour = 10 Hours.

You need to give them a good, long charge.

Then not ever let them below 12.24 Volts, 50%.

When they are charged you will be able to see if any are shot, or if its your regulator.




Mark

[Captain Bill]

One other thing I thought of, how big are your wires going from the charger to the batteries and how long is the run? A poster on another forum recently took delivery of a boat where the wiring was woefully undersized for charging his large bank and the voltage drop was causing him problems. While the charger was seeing the requisite 14+ volts, the batteries were never seeing much over the high 12s or low 13s. The result was the batteries were never properly charged and his voltage regulators on all his charging sources were going into float prematurely. His monitor was measuring voltage at the charging end rather than the battery end and all looked good though he was always low on actual capacity. He also found several other problems with the wiring when he had an outside electrician look at it. Just because it's a new boat doen't mean that someone didn't make a mistake in the wiring.

[daddle]

Mark is of course correct about those voltages. However one should be aware of two very common situations:

1 - These are the terminal voltages. The voltage reported by an instrument some distance away on the other side of some wire and connections and shunts is often significantly less.

2 - These voltages are at some standard temperature. In the battery box on a hot tropical day one must use voltages up to 0.4V less. I recall it is -0.022V per degree C. That is the about the difference between 100% and 50% charged.

On a hot day my panel meter reads around 11.90 when the specific gravity shows a 50% charge. It's on the far side of fuses, breakers, shunts, long wires and numerous connections.

[djmarchand]

Not sure if it is relevant, but I just read a test of battery voltage versus resting time. The conclusion is that if you don't let lead acid batteries rest (no charge and no load) for 24 hours, then the voltage readings are worthless as an indicator of state of charge.

But specific gravity is a valid indicator. Get a hygrometer at an auto parts shop and check your cells.

My take on what I have read so far is that the charger(s) are ramping down too early. The batteries may or may not be good. Can't tell without starting with fully charged batteries (as measured with a hygromteter).

David

[hellosailor]

Phil-
As you see there are many questions and as I think you also see, take nothing for granted. Buy a good multimeter (like a Fluke that has been calibrated) to confirm the output from the chargers and the battery. This can also be used to test for voltage losses in the wiring, i.e. if you put one meter lead at the battery common positive and the other lead at your battery switch and it reads 00.50" volts, you have a half volt of loss. Unacceptable, and probably indicating a loose or dirty terminal connection, or an internally rotted cable.

The hydrometer is priceless, because you may have one or more bad cells. If the batteries were allows to sit at some point, even before installation, they may have sulphated and been permanently damaged. It can happen. A hydrometer or a test with a good volt meter can tell you this, but as long as you have wet cells, get a good hydrometer (the $10+ one not the $3 one <G>) and if you are new to batteries, remember that it WILL drip acid no matter how careful you are, wear old clothes, expect holes in them, chase after acid drops and find something to stow the hydrometer in, if it doesn't come with a case. To control those acid drops.

Wait for Dolphin's reply on dualing controllers but if necessary, just use ONE for twice as long, it will be supplying about a 1/10th "C" charging current and that IS sufficient to work if given enough time.

The batteries amy well come up to snuff simply by cleaning up the cables and giving them an equilization charge. One of the inexpensive books like "The 12 volt Doctor" or "the 12 volt Bible" will also give you a nice concise source for troubleshooting a lot of boat battery problems.