More battery issues

[boristhebold]

Lots of posts on here about battery issues and the difficulties we all tend to have trying to identify the problems and whether batteries are sound or not. I will do some research when I get some time.

I have an inkling one of my two batteries is on way out even though it started the 200hp yam and seemed fine all day. On Friday I had to wait for ages on the quay side of the Poole lifting bridge as the lights were on red. After 10 mins of waiting and no activity I got fed up of boats going through on red and so attempted to radio bridge control, as soon as I went to transmit the VHF went dead and so did the garmin gps unit, voltage on batt showing as 12.6 . When normally underway voltage shows as 14.2 but in this situation the engine was idling for 10mins. I had to use my handheld to call bridge control who did not reply but did switch the lights to orange as in safe to proceed. Perhaps they were asleep at the time.

So I deduce that such is the drain on batteries from electrical systems and some use by the engine that the batteries need the engine to top them up and when you have an old battery which may be past it's prime issues can occur.

I think I'm going to change both betteries every couple of years to be on safe side.

As to Poole bridge control I'm getting fed up of lights not working on twin sails bridge or just stuck on red on Poole lifting bridge the older bridge for no reason, had many experiences and other boat users are getting so fed up they are beginning to ignore the
lights and ignoring which route they should take on twin sails bridge. I sound like a grumpy moaner LOL.

[A1an]

You are spot on. Very few generators/alternators will produce a charge at idle so your battery has run out of puff with not being charged by the engine, it should last a good bit longer than 10 mins although GPS ect can be a heavy drain.

If decent marine/leisure batteries are used and the engine is charging properly then there is no reason why they shouldnt last for many years with the proper care.

[willk]

Just a thought. Try using the VHF & Plotter before you start the engine next time. If the electronics fail, turn them fully off and try to start the engine. If the engine starts, then you may have a wiring problem, not a weak battery.

It strikes me as odd that the battery would start a 200hp motor but not run a VHF etc.?

It might be corroded copper in the wiring. I'm no Spark, but I'd expect battery volts to drop back to 12.5v under the circumstances you describe. If you have poor copper, the lower voltage might not be enough to supply the amps needed on the equipment side of the bad copper. As I say, just an idea.

[Hightower]

Sorry to hear you're having problems.

My outboard outputs plenty of voltage at tick over. I would suggest cleaning all your earths and major connectors just as routine maintenance. There are dealers around that can test your batteries to check if they are OK.

You don't say how old your batteries are but certainly should last more than 3 years. If you do have to replace your batteries due to them being at the end of their life, I cannot stress enough how important it is to store your battery fully topped up with charge. If this means plugging a charger in the wall and doing it this way, then so be it.

[butty]

had a similar situation last week, the engine starter battery was playing up and show low voltage, only a year old.

removed all terminals and cables off terminals, gave everything a good clean up and refitted together and all was fine...

its amazing how a little corrosion can stop a battery operating as it should.

[jyasaki]

If your battery was showing 12.6, and the VHF pulled down the supply line (feeding the electronics), I'd be looking at wiring between the batteries and electronics.

If the battery voltage didn't drop, the problem isn't the battery.

jky

[boristhebold]

The battery in question is about 4 years old so I shall replace shortly along with the battery cables. The newer battery is about 1 year old with new cables so not an issue. I’ve had issues with a battery before failing as I went through Poole harbour entrance which not only cut out all the electronics but started making my engine miss fire/run bad, luckily I had fitted a second battery and switched to that one.

As I’ve now done a bit of reading on this subject and actually bought a book about marine batteries a few things have stuck in my mind which may be useful.

1. When you have two batteries in parallel and are running from one battery the battery with the least charge will actually draw charge from the one with the most charge, so you could find a situation where a failing battery will potentially bring down the other battery.
2. Where you run with one battery selected one week and the second battery selected the following week (or trip out) you can easily forget which one you used last time which can cause one to become more discharged.
3. There are numerous options for battery management and numerous gadgets to assist but it can be rather complicated.
4. There is a very limited range when you battery is either good and will operate well or bad and wont. If you had a scale of say 1 to 100 then the good operating range in terms of charged range is about 35% or so on average so thing from 70% charged it will be OK, anything less and it could be a problem.
5. You cannot check whether your battery is good by simply measuring the voltage. Even if it says 12.6V that doesn’t mean that the battery is any good.
6. The best way to check a battery is doing a load test, you need to disconnect something (depends on engine) to prevent engine from firing / starting up and test the battery when you try and start and measure load (more info out there on this)

In my case as the volt meter on my console was showing (with engine running) 12.6V on this battery and normally it would show 14.2V from past experience I am going to presume the battery due to age is on the way out. So will be replacing shortly and will also replace the battery cables at the same time.

Will also now choose the selector on the battery isolator switch to both when I go out in order to charge both batteries at same time.

And will be checking my batteries every year.

Would recommend for your boating library a book I just purchased and mentioned called “The 12 volt bible for boats” by Miner Brotherton and Ed Sherman, it’s a challenging read but interesting and makes some good relevant points. I’ve only read a few snippets so far.

[Erin]

Originally Posted by boristhebold

In my case as the volt meter on my console was showing (with engine running) 12.6V on this battery and normally it would show 14.2V from past experience I am going to presume the battery due to age is on the way out. So will be replacing shortly and will also replace the battery cables at the same time.

Don't think it is the battery. If the engine is running and you only have 12.6v at the battery then there is a wiring problem. If your wires are good then you will see 14.v at the battery (basic alternator voltage) irrespective of whether any significant charge is being accepted. I suspect a wiring issue.

[jyasaki]

Originally Posted by boristhebold

1. When you have two batteries in parallel and are running from one battery the battery with the least charge will actually draw charge from the one with the most charge,

Not with a "1 - 2- Both - Off" selector setup. You will draw off either 1 or 2 and they will be isolated from each other. In off, they will also be isolated, as will electrical accessories from the batteries. On Both, the weaker battery will draw current from the stronger to the point they are voltage equalized (which may be enough to render both batteries useless, which is why you don't want to always run on "both".)

2. Where you run with one battery selected one week and the second battery selected the following week (or trip out) you can easily forget which one you used last time which can cause one to become more discharged.

By week? Long time. Many I know run out on one battery, and back in on the other. I, being less organized, switch between them when I think about it in order to keep them both charged.

3. There are numerous options for battery management and numerous gadgets to assist but it can be rather complicated.

Yup. I think the best thing is whatever works for you (and your wallet.) Most solutions will work, as long as you understand their benefits and limitations, and work within the constraints of your systems design.

4. There is a very limited range when you battery is either good and will operate well or bad and wont. If you had a scale of say 1 to 100 then the good operating range in terms of charged range is about 35% or so on average so thing from 70% charged it will be OK, anything less and it could be a problem.

Really depends on the setup. A high draw motor and a smallish battery may need a 90% charge to crank. A lower draw motor and a big battery may crank on 60% charge. In general, it's considered bad to draw a cranking battery below about 70%. Deep Cycle batteries (what you call Leisure batteries, I think) can be drained to below 50% without major damage. These are for "good" batteries. As cells begin to go bad, things change.

Rereading your paragraph, I became less clear on what you were saying. So maybe disregard my statement. Or not, if it works. Dunno.

5. You cannot check whether your battery is good by simply measuring the voltage. Even if it says 12.6V that doesn’t mean that the battery is any good.

True.

In the same way, you can't tell water temp by looking at it. But, if it's steaming, you have a pretty good idea that it's warmer than the air. If there's ice, you get a good idea it may be cold.

A battery that is charged and at 12.6V, that, when unused (no load) and rechecked in a couple of hours and reads 12.1V, is likely bad. A battery that has a significant voltage drop with a light load is likely bad. A battery that holds voltage over time, and with a load is likely OK. A voltmeter is tool that gives data; how you interpret that data and come to a conclusion on next actions is key here. A single data point is inconclusive by itself, unless it's way out of normal range. What you want is data from the entire range of use to see what happens to the voltage in different circumstances. And, when in doubt, pull the battery and have it load tested.

In my case as the volt meter on my console was showing (with engine running) 12.6V on this battery and normally it would show 14.2V from past experience I am going to presume the battery due to age is on the way out. So will be replacing shortly and will also replace the battery cables at the same time.

On the face of this paragraph, I'd say you can't deduce a bad battery. Too many other possible problems: bad cabling (which you said would be replaced), poor alternator output, or some other device pulling the voltage down. A little more isolation would be called for if I was troubleshooting.

jky

[Oscarguitar]

Boris,

Have you thought about getting a VSR? This will charge both batteries, engine start first and safeguard your engine start battery only allowing it to draw down to a certain voltage before isolating it and using only the house battery for accessories. I fitted one two years ago and I know a number of others have the same set up. Very reliable and idiot proof so suits me well. You don't need to remember which battery to use. If you already have two batteries fitting it should be straightforward. The BEP VSR is the one fitted by Cobra and the one that I used for my boat. Powerstore in Poole stock them.

http://www.power-store.com/view-item...d=1159&id=199&

[Steve_B]

Mark
Re Bridge/Lights issues, please ensure that you write/email the Harbour Master at PHC, as this is a regular problem that we all experience and the more that complain, the quicker it will be sorted.
I have been stuck on Red and seen the bridge control outside the "office" having a quick fag!

[Tim_B]

Other than the VSR there is also the split diode - although would like to avoid the pros and cons of both as it would have been done many times before :-)

cheers
Tim

[Ian M]

Originally Posted by Oscarguitar

Boris,

Have you thought about getting a VSR? This will charge both batteries, engine start first and safeguard your engine start battery only allowing it to draw down to a certain voltage before isolating it and using only the house battery for accessories. I fitted one two years ago and I know a number of others have the same set up. Very reliable and idiot proof so suits me well. You don't need to remember which battery to use. If you already have two batteries fitting it should be straightforward. The BEP VSR is the one fitted by Cobra and the one that I used for my boat. Powerstore in Poole stock them.

Power Store

+1

[kubcat]

I had a problem with my tow truck where sometimes after a nice long drive it wouldn't start as it would crank too slowly. If I kept cranking, the battery would go completely flat very quickly. If I left it long enough without first flattening it completely, it would start fine.

The voltage read fine whenever I tested it. I replaced lots of wiring, connectors, battery leads etc with little change. Out of frustration I purchased a new battery when I couldn't start after refueling.

This new battery cured all my starting problems. When I discussed this with an engineer friend of mine, he did a load test on the old battery after a recharge and it turned out it was past it's use by date, even though a straight voltage test indicated it was fine.

[Nightfisher]

Originally Posted by kubcat

I had a problem with my tow truck where sometimes after a nice long drive it wouldn't start as it would crank too slowly. If I kept cranking, the battery would go completely flat very quickly. If I left it long enough without first flattening it completely, it would start fine.

The voltage read fine whenever I tested it. I replaced lots of wiring, connectors, battery leads etc with little change. Out of frustration I purchased a new battery when I couldn't start after refueling.

This new battery cured all my starting problems. When I discussed this with an engineer friend of mine, he did a load test on the old battery after a recharge and it turned out it was past it's use by date, even though a straight voltage test indicated it was fine.

Once had the same problem, mine would turn-over but not start after refueling or shutting-off for a brief period 2-10 min or more on warmer days.
It was a No Spark condition. After a series of tests (batt voltage fine), etc.. and months of changing-out almost all electrical primary/secondary items and going through two starters, the only thing left to change was the magnetic pick-up inside the distributor. Boom--away it went and never had another hot start problem.