Help with a flat start battery

[Ronje1]

The kincrome looks good however it’s only suitable for lead acid battery’s apparently

Who told u that?

Suitable for lead acid batteries DOESN'T mean lead acid batteries only.

An AGM battery IS simply a lead-acid battery with the acid absorbed into a f/glass matt. Hence the name AGM (Absorbed Glass Mat).

The acid (electrolyte) soaks into the fibreglass mat like a wet sponge and is held in place by pressure and plastic separators. Acid doesn't slop around inside the case like it used to with a simple lead acid battery of old.

This'll do the job which is a simple way of telling if the battery is OK or not under load.

Bit about construction of an AGM for ya.

[seastrength]

Who told u that?

Suitable for lead acid batteries DOESN'T mean lead acid batteries only.

An AGM battery IS simply a lead-acid battery with the acid absorbed into a f/glass matt. Hence the name AGM (Absorbed Glass Mat).

The acid (electrolyte) soaks into the fibreglass mat like a wet sponge and is held in place by pressure and plastic separators. Acid doesn't slop around inside the case like it used to with a simple lead acid battery of old.

This'll do the job which is a simple way of telling if the battery is OK or not under load.

Bit about construction of an AGM for ya.

Looks like another trip to Bunnings!😉

[Ronje1]

The Kinchrome will give u the ability to test the battery under load. You can forget about measuring current, voltage, temperature and analytical analysis. There's a time for that stuff and this isn't one of those.

Step 1.
Fully charge the battery and then let it sit for an hour or so. Disconnect boat electrics from battery (both terminals).

The tester will have an instruction sheet with it.

Connect the tester alligator clips to the battery posts (red-red). Note where the needle reads.

Press the little spring-loaded silver switch and see what happens to the needle on the meter. See if it holds up within the little coloured segment limits for the 10 seconds or so recommended. Pretty much the same as a crank test with starter except you're

measuring with an instrument rather than listening for cranking speed by ear. The calibrated load inside the ventilated case will heat up but don't be alarmed if a bit of smoke comes off it too at first.

THAT test will tell you if charging was successful.

In 10 - 14 days, test battery load again. If OK then the battery is holding charge OK.

Step 2

If battery is holding charge OK then start looking for parasitic draws from boat electrics.

Make sure that ALL of the switches are OFF.

Put a current meter in line between the positive post and the boat electrics main cable that bolts onto it. Make sure the meter leads are the right way round. Red to the red post and black to the boat electrics bolt on connection.

Put ammeter on max (for initial protection). Then gradually cycle down the ammeter ranges until you get a result. DO NOT turn anything on while u are measuring current or you may need a new meter if protection doesn't work.

I think I saw that you measured a figure of .01 amps draw. Just make sure that figure is correct. See what amp range u're on to get .01. (Sounds like a digital meter) .01 indicates that yr ammeter is on amps range.

What is make/model of yr meter?

Be nice to know what's drawing current anyway so look for what's doing it.

10 mA isn't going to drain yr battery over 2 weeks. 100ma or more certainly will cause a problem over that period.

That Kinchrome will also tell you if the alternator is working.

Once everything is connected back up, check volts with the tester by connecting the alligator clips (about 12v or so). DO NOT press the little silver switch on the tester. Start the motor. Volts should drop on cranking and rise when motor starts and needle

moves up into the little coloured charging test box on the dial

The Seamaster start battery is only 14 months old and fully recharges overnight and tests 800CCA when fully charged only to slowly discharge over a two week period despite weekly use.

Does this mean that you charge the battery with yr 240v charger and then use the boat regularly only to find the battery flat after a couple of weeks use?

Are we talking about a MFM87 battery (800cca)?

One possibility from those symptoms is that the alternator on the motor isn't charging. Looked at that? Charges OK on yr 240v charger.

If alternator isn't charging then the battery has to deliver ALL of the electrical demand of the boat while u're out and about so it goes flat after a few outings.

Do the charging test BEFORE u do anything else.

[NAGG]

I thought so myself, but the battery is only 14 months old. The battery shop staff keep telling me the battery is working fine because it is becomes fully charged overnight on their charger. They maintain that it is discharging due to a circuit fault, however, I can find no reason for the discharge in the starter circuit. If it fails the load test, I will ask for a warranty replacement. Thanks everyone for their input. SS

Then it's simple to test ...... don't connect the battery & with a multimeter - test it every 24 hrs ..... you'll soon see if there is a problem .

Chris

[Ronje1]

No point in getting a replacement battery if the o/b motor isn't charging it. Any load test will be meaningless.

So the "is the o/b alternator working" test hasn't been done.

Get it done.

Its just the opinion of the battery shop guy that it must be something draining the battery without checking the alternator.

I'd be looking for a new battery supplier but you're thinking about warranty (guessing) if you go somewhere else.

It charges OK o/night at your place. By charging it o/night at their place, they're only duplicating what you already know.

Do the charging test BEFORE you do anything else. Eliminate that as the cause.

Its odd that they've given you an opinion (that's all it is. A guess) without checking out the alternator. A guess. Pretty basic stuff for a battery supplier.

If you don't feel confident on doing the charge test yourself, take the boat down to the battery shop.

They can soon tell you if the alternator in the boat is working or not.

Better still, do the simple test yourself (it really is simple) then you don't have to rely on somebody's opinion. Just facts. I'll talk you through it.

I'll send you a phone number via a pm so I can talk you through a charging test as you do it, if you like.

[Paul071978]

Just stating The kincrome manual mate

[Ronje1]

Yes, I know Paul, but lead acid batteries are NOT just a flooded type like they used to be. Where the electrolyte (weak sulphuric acid) slops around in liquid form like water inside the case and where the caps can be taken off and the specific gravity (strength) of the electrolyte can be tested with a hydrometer (squeegie).

Sealed lead acid (SLA) and Valve Regulated lead acid (VRLA) batteries also fall into a similar type. They're sealed or vented but are still lead acid.

AGM batteries are also lead acid but the electrolyte is absorbed into a f'glass "cloth" like a kitchen sponge held between the plates to stop it slopping around.

They are also sealed and gases produced in the chemical processes of use are recombined within the battery. The chemical recombination process within the sealed battery case maintains the correct specific gravity of the weak electrolyte providing the correct charging is maintained.

If the charging gets "out of whack" then the battery suffers.


KP1460_1.pdf (kincrome.com.au)

[seastrength]

Then it's simple to test ...... don't connect the battery & with a multimeter - test it every 24 hrs ..... you'll soon see if there is a problem .

Chris

Thanks Chris
This seems the simplest approach to date. Willdo. Cheers SS

[Paul071978]

Yes I understand the internal configuration is different however with my fancy digital load tester I have to select the battery type ie lead acid or gel or AGM or VRLA before the test load is applied so assume the test must differ between type

[seastrength]

I repeated the load test today after battery was in iso (no connections to motor or instruments) and reading was 794 CCA, a drop of 6 units in four days. I think the problem may have been in the main circuit due to power drain from the Helix 9 before I separated the the start and accessory circuits. I think I will invest in a battery isolation switch as Steve suggested previously. Thanks everyone for your helpful information and advice. Cheers SS.

[Fed]

A battery isolation switch will add 6 more places for your electrical system to fail which can also destroy your rectifier if connected to the motor, plus you have to buy it, mount it & wire it in compared to undoing a nut.
I chose the nut.
If you're putting the iso switch on the 'other' battery then it doesn't matter if the switch or additional wiring fails as it won't stop or harm your motor.

Nearly forgot, how are you testing to get the CCA reading?

[Dignity]

A battery isolation switch will add 6 more places for your electrical system to fail which can also destroy your rectifier if connected to the motor, plus you have to buy it, mount it & wire it in compared to undoing a nut.
I chose the nut.
If you're putting the iso switch on the 'other' battery then it doesn't matter if the switch or additional wiring fails as it won't stop or harm your motor.

Nearly forgot, how are you testing to get the CCA reading?

Question I previously asked but still waiting

[seastrength]

Question I previously asked but still waiting

Missed your question previously Dignity. Apologies for that. The load test was done consecutively by the battery vendor to minimise measurement error. I am hoping this will sort out the problem and was thinking about adding a battery isolation switch to reduce power loss. Howeved, will reconsider after a weeks run on Lake Monduran. If the battery does not hold charge, I will need to check the alternator on the Honda. Thanks again for all previous help. Cheers SS.

[Dignity]

SS, very easy to check if the alternator is working. Start your motor and measure with your multimeter and keep the revs up a bit and you should see an increase in battery charge, if not then suspect your alternator.
Or after doing a bit of run check the voltage.

[Ronje1]

Hard to figure why SS doesn't want to do a simple alternator test himself before going anywhere.

Yes I understand the internal configuration is different however with my fancy digital load tester I have to select the battery type ie lead acid or gel or AGM or VRLA before the test load is applied so assume the test must differ between type

Paul, if the fancy digital load meter is based on a simple voltage test, then there will be voltage differences between battery types which have to be taken into account. Hence the "select a battery type option".

eg A calcium battery has a higher voltage than a lead acid type. 15v.

A proper load tester measures actual current draw and THAT doesn't matter what type of battery the amps are coming from.

Got a few details on the load tester?