New Battery Losing Charge

[Splash]

Hi Splash
Does your motor have a regulator/rectifier or just a rectifier fitted? The regulator/rectifiers use a very small amount of power just by being connected to the battery, engine not running.
Station-rat

Thanks SRAT!

I think I just have the rectrifier. Where can i locate the regulator if I do have one?

SPlash

[Splash]

People.

After all this, my problem of battery going flat still remains.... :-(

What other troubleshooting pointers can you lead me to?

Splash

[station-rat]

Have you checked if the battery is being charged when running?
What is the voltage when running?
Station-rat

[station-rat]

What makes you think that the battery is going flat? No I am not trying too be funny
Station-rat

[Splash]

TRHanks SRAT.

How to check if battery is being charged wehn running?

Last Monday I was 30km out at sea and I was unable to start my engine. Fuel was not the issue. When I limped back home, I put my battery on the charger and looked at the charge - half flat. That's why I think the battery is going flat. I was unabel to start my donk at home to flush so I connected the charge to battery. Waited for 2 hours, then I was able to start/flush my donk.

Splash

[station-rat]

Ok
You need to borrow the multimeter.
Check voltage before you start, and again after it is running.
If the voltage is higher with it running,that is good.
If the voltage is the same or lower that is bad.
You probally wont see a big increase in voltage at idle, but you should see some.
Station-rat

[Splash]

Thanks.

To pre-empt things more:

If voltage is lower or same whilst running, what components do I investigate/troubleshoot?

Splash

[station-rat]

rectifier ---Test with multimeter
Coil under flywheel --- Test with multimeter
Your tacho still working correctly?
Station-rat

[Splash]

Thansk SRAT!

How do I test rectifier, coil and tacho?

What voltage should I see on a fully charge healthy battery?

What voltage should I see on battery when it's donk is running on water?

Splash

[driveon]

Hi Splash, you should be getting around 14 volts with the motor running but I would recommend you take you boat to an auto electrician or marine auto electrician because there are a number of situations that can occur and you just won’t know which device is causing the problem.

For example, because many marine motor alternators are fairly small, if you battery is stuffed and you get the motor running, if you measure the voltage and find it’s low, you won’t know if it’s low because the alternator is faulty or the alternator’s voltage is being pulled down because the battery is faulty.

Getting a flat battery in your car is one thing but getting a flat battery while miles out to sea seems to me to be a bit scary.

Cheers

[station-rat]

Splash
PM sent
Station-rat

[Poseidon]

Are you sure that you have no other loads connected to the crank battery, a sounder etc?

The reason I ask is that I went and measured the load on my battery and found 2.19mA being the load of the sounder sitting turned off, this is quite normal as many sounders will consume power sitting switched off.

Even this 2.19mA has little effect on the battery as there have been times that I have forgotten to turn off the isolator and the battery still cranks over the motor some weeks later.

With the sounder unplugged the load on the battery is zero amps.

Picture attached is the reading with the sounder connected.

Hope this helps.

[Splash]

PM sent SRAT.

Thanks Posoiden. - I purposely wired up second battery for stuff like sounders. I am sure which wire are which and I am sure the sounder wires are not connected - even on my second battery.

Interesting thoughts.

Splash

[FNQCairns]

Hey Splash, what about chargeing the problem battery up, fit it, pack a multimeter onboard + another spare trusted and fully charged battery then go fishing.

Hang and travel close inshore and at cruise speed get someone to measure the volts at the battery, anything between 13.5 to 15.5 would lead me to believe without further evidence the engine side (charging) is Ok.

Then I would look toward all ignition connections (ignition switch also) for high impedance (sp), I wouldn't strictly need to do this with a multimeter I could simply pull each clean and shine them then refit, working on the idea that this is a good thing to do anyway and the possibility that once on the water you may have a connection may not like offshore salt air ie spray landing in the boat constantly sometimes.

Then in the absence of any further symptoms I would carry a spare battery for a while but condsider it fixed.

Noises eminating from an ignition switch when turning the key is a very good indicator of a poor/loose/dirty connection somewhere even at the ends of the battery cables, salt spray really plays havoc at times given a little time but batterys are pretty robust and unless abused somehow hardly ever cause a problem by the odds but of coarse they can be at fault also.

cheers fnq

[driveon]

Hang and travel close inshore and at cruise speed get someone to measure the volts at the battery, anything between 13.5 to 15.5 would lead me to believe without further evidence the engine side (charging) is Ok.

Hi FNQCairns, 13.8 to 14.7 is the correct charging voltage range for automotive and marine batteries.

Any lower and the battery will not fully charge and may not charge at all.

Any higher and the battery will be cooked and most AGM and Gel Cell batteries have a maximum recommended charging voltage of 14.4.

Cheers