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Help! Is 15.4v a problem?


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we have 2x 230ahc 12v Haze gel maintence free batteries, and a NASA BM-1 battery/charging monitor (which i love!).

Before i start the engine, the BM1 reads:

13.5V
Charging 2.4a (from Solar - inverter off, no 12v load)
88%C
Time to Charge 25hr.
731 Int Ahr.
I start the engine and....
Between 15.2 and 15.4V
Charging between 1.2 and 4.2a
Time to Charge between 9.3hr and 77hr.
732 Int Ahr

help.gif

Is this voltage too high??

ALSO the D Battery warning light is flashing about once per second with an accompanying chirrup and a "hunting" of the engine revs - this at about 1200 rpm. Nothing above changes at 1400 rpm and a good engine rev makes no odds.

At tickover the warning light is solidly on.

The engine is a Beta38 with a 100A alternator..

The Label says : LSKRA 14V 100A. (AAK5535)

alternator

We both have a week off next week so i'm thinking of getting someone to look at it, BUT..
Am i likely to "fry" the batts at 15.4v if i take a few hours to chug from the bottom-ish of the Ashby to (say) Springwood Haven? (EEK! unsure.pngsad.png )
Any one else know any marine sparks up this way ?
Currently @ Trinity Marina but supposed to be moving to our new mooring between bridges 4-5 on the Ashby on Saturday (soooooooo happy about this!!biggrin.pngbiggrin.png )
help.gif

 

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Is this voltage too high??

 

Simple answer YES

 

From info on-line for said batteries

 

Max. 2.4 VPC Max ripple 3.5%

 

This Max is equal to 14.4 volts assuming a 12v system, ripple maximum would give a maximum voltage of 14.9v (not at that constantly though)

 

At a guess looks light a regulator fault in the alternator.

 

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I can't be much help but I think that you are risking battery damage. Beaten by Bottle!

 

It could also be a blown field diode. Put a voltmeter between D+ and B+ and rev the engine. The meter should read well under 1 volt. If not probably field diodes.

 

I also wonder if its the solar controller. Try it with the solar panels covered.

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Simple answer YES

 

From info on-line for said batteries

 

Max. 2.4 VPC Max ripple 3.5%

 

This Max is equal to 14.4 volts assuming a 12v system, ripple maximum would give a maximum voltage of 14.9v (not at that constantly though)

 

At a guess looks light a regulator fault in the alternator.

 

 

So by going on a run - i WOULD be risking a frying of batteries - bum... even by a 2 hour chug down to our new mooring? (she said hopefully!) Really thanks heaps for replying though... i'm trying to get my head around this stuff so hard it hurts!

 

I can't be much help but I think that you are risking battery damage. Beaten by Bottle!

 

It could also be a blown field diode. Put a voltmeter between D+ and B+ and rev the engine. The meter should read well under 1 volt. If not probably field diodes.

 

I also wonder if its the solar controller. Try it with the solar panels covered.

 

 

So sorry Tony - you are an LX god (i have been trying to get my head around reading your online courses!) and i am an utter numpty and a fule.... Where or what is D+ and B+? As above, i'm really grateful for this help!!

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To the experts - with these particular batteries would equalising every now and then be recommended? What voltage would good equalising take place?

 

I thought the voltage in question was 15.5V and, if I am right, a couple of hours at 15.5V might even be good for the batteries.

 

To the OP - I may be wrong, so wait for some consistency of responses!!

 

Edited to add - I am wrong in your case. As per Bottles response, gel batteries should not be equalised, and I'm recalling their max voltage is around 14.4V.

Edited by Richard10002
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Gel,AGM, sealed and maintenance free cannot and must not be equalised.

 

The only batteries that can be equalised are Open Wet Lead acid

 

Equalisation causes excess gasses,and water loss, which can only be replaced in Open Wet Lead Acid batteries.

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Some further info :

 

a ) The Alternator is an Iskra - you could try an auto electrician for a regulator (e.g. http://autoelectricalpartsuk.co.uk/, although these people are not near you - will be more local ones)

 

b ) The terminals referred to are on the Alternator

 

c ) The voltage is too high - you should find out what the battery chemistry is exactly and ask the manufacturer what the proper charging voltage should be set to for these. There are several types and each has their own requirements for charging voltage They sound expensive batteries and it would be a shame to damage them by frying them unwittingly. I had a quick look for you but couldn't find the info - will try again later

 

Hope that helps,

 

Nick

Edited by Nickhlx
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To the experts - with these particular batteries would equalising every now and then be recommended? What voltage would good equalising take place?

 

I thought the voltage in question was 15.5V and, if I am right, a couple of hours at 15.5V might even be good for the batteries.

 

To the OP - I may be wrong, so wait for some consistency of responses!!

 

Will do chap! Have to nip out for a few hours now but i will pick this up later - my aged parents need a few hours attention on my day off... Not for the first time i am thanking my lucky stars at finding this forum - some amazingly generous posters on here.... and i'm such a worrier! This has been bugging me all week since i noticed it at the weekend... i was worried i'd fried the batteries (chugged for 2 hours before i noticed the high voltage!), but they seem ok...

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I you really need to move you could always remove the fan-belt going to the alternator and run for a couple of hours without charging.

 

HOWEVER -make sure that your water pump is turning - it may be driven by the same belt.

Edited by Alan de Enfield
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Some further info :

 

a ) The Alternator is an Iskra - you could try an auto electrician for a regulator (e.g. http://autoelectricalpartsuk.co.uk/, although these people are not near you - will be more local ones)

 

b ) The terminals referred to are on the Alternator

 

c ) The voltage is too high - you should find out what the battery chemistry is exactly and ask the manufacturer what the proper charging voltage should be set to for these. There are several types and each has their own requirements for charging voltage They sound expensive batteries and it would be a shame to damage them by frying them unwittingly. I had a quick look for you but couldn't find the info - will try again later

 

Hope that helps,

 

Nick

 

Info in post #2 came from on-lne PDF from manufacturer. wink.png

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I would agree - however she did say that the solar was charging when that reading was taken and there was no load being applied, so that doesn't seem an invalid reading ...

 

Definitely worth checking the voltmeter though as if you are working with faulty readings a lot of time could be wasted chasing a non-existent fault ..

 

Nick

 

 

Bottle - Missed that in my haste to help rolleyes.gif

 

Nick

Edited by Nickhlx
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If the start voltage of 13.5 is after some use I would suspect the voltmeter is reading high......

Get an independent voltmeter and check the onboard meter.

 

This voltage 13.5 was from solar charging at 2.4 amps post #1

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Will do chap! Have to nip out for a few hours now but i will pick this up later - my aged parents need a few hours attention on my day off... Not for the first time i am thanking my lucky stars at finding this forum - some amazingly generous posters on here.... and i'm such a worrier! This has been bugging me all week since i noticed it at the weekend... i was worried i'd fried the batteries (chugged for 2 hours before i noticed the high voltage!), but they seem ok...

Forget what I said about equalising at 15.5V. I missed the fact that you have gel maintenance free batteries, which shouldn't be equalised! My recollection is that anything over 14.5V may be too much for gel batteries.

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In order to move the boat, I would try turning on as much load as possible (all interior lights, tunnel light, tv etc) and then start the engine and check the voltage. But if it stays up above 14.6v or so I would stop the engine and get someone out to test and service the alternator.

  • Greenie 1
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In order to move the boat, I would try turning on as much load as possible (all interior lights, tunnel light, tv etc) and then start the engine and check the voltage. But if it stays up above 14.6v or so I would stop the engine and get someone out to test and service the alternator.

This is exactly what we had to do when we discovered a fault with our new alternator at the beginning of this year. Ran back from West Stockwith with every electrical item we had running to keep the voltage down to an acceptable level.

 

The dodgy alternator was running fine when the batteries were discharged but as soon as they approached fully charged the voltage went off the scale. Was a faulty voltage regulator. Got the alternator replaced under warranty.

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In order to move the boat, I would try turning on as much load as possible (all interior lights, tunnel light, tv etc) and then start the engine and check the voltage. But if it stays up above 14.6v or so I would stop the engine and get someone out to test and service the alternator.

 

clapping.gif

 

Got back to the boat and did exactly as you had advised - also regained my sense of humor as we oh-so-assiduously made sure we were low power on everything i only managed to muster about 24A, including the slow cooker - no TV - just low powered laptops!

 

Sparked up the engine and she settled at 1200rpm at 14.7v... (charging at 3.2a on average) Will we get away with that?

 

Will have a scout around for more power-hungry stuff.

 

Oh.... the irony! laugh.png

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clapping.gif

 

Got back to the boat and did exactly as you had advised - also regained my sense of humor as we oh-so-assiduously made sure we were low power on everything i only managed to muster about 24A, including the slow cooker - no TV - just low powered laptops!

 

Sparked up the engine and she settled at 1200rpm at 14.7v... (charging at 3.2a on average) Will we get away with that?

 

Will have a scout around for more power-hungry stuff.

 

Oh.... the irony! laugh.png

If you have an Irony, plug that in too! don't burn yourself though!

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If you have an Irony, plug that in too! don't burn yourself though!

Sat in car pmsl! Sadly we only have a 600w inverter...

 

A heartfelt thanks to all, was feeling a bit lost with this earlier..... :-)

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clapping.gif

 

Got back to the boat and did exactly as you had advised - also regained my sense of humor as we oh-so-assiduously made sure we were low power on everything i only managed to muster about 24A, including the slow cooker - no TV - just low powered laptops!

 

Sparked up the engine and she settled at 1200rpm at 14.7v... (charging at 3.2a on average) Will we get away with that?

 

Will have a scout around for more power-hungry stuff.

 

Oh.... the irony! laugh.png

Headlamp should use a fair bit. And blow the horn all the way. 14.7 should be fine.

Edited by bizzard
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