13.1v - indication of problems or good news?

duncan

duncan

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Not having used the boat for some time I put the main battery onto a 20A 'smart charger' for a couple of days.

It is basically a coach battery - 1000CCA, 180Ahr calcium technology designed for heavy loads and cycles.

Returning I was told it was fully charged.

On the boats instruments it was showing 13.1v, which I put down to it being 'hot' and expected it to drop back to 12.8v over the next few hours. Instantly started the engine, ran a couple of hours to Yarmouth and it still showed 13.1v.

Next morning it still showed 13.1v........

Has the charger done a really good job.......or is this an indication of a problem?

(I trust the instrument readings - more than one say the same thing and have been accurate for years).
 
13.1v is about right for a fully charged battery.... I think. Sounds like you have a good battery there. Our instrument panel meter shows 1.2v less than the battery terminals.
 
A suitable disclaimer

13.1v is about right for a battery in 'good health'...If you are concerned about any of your frail electronics then worry not...you are in absolutely no danger of 'frying' anything.....but then, of course, this is not my boat !!
 
[QUOTE=jonic;3095727]I have spent most of my cruising life trying to get my batteries to 13.1.



...had you been charging the battery ,as per post, from the mains for the past few days or relying on your on-board system? A 'new' battery is designed to produce in excess of 13 volts...end of story...I'm not sure why the original poster even worries about this...12v...13v..great! if it showed 7v then that's a worry..

Don't know why am I even bothering to type this drivel.....
 
pvb said:
Really?
Click to expand...

yup...read this...quickly copied from a website chosen totally at random...

he hybrid battery is more resistant to deep cycling than the lead/calcium, but is still not as good in this respect as the original lead/antimony style. Most cars supplied with hybrid batteries have their voltage regulators set to 14.3 volts, although it is reported that the higher 14.8 volt setting of GM cars does no harm if the water level is checked regularly.

A fourth type, the "gel cell", has appeared in automotive use. Early reports were that its manufacturer recommended charging at 13.8 to 14.1 volts (2), suggesting it used hybrid chemistry. However, it also does not allow the user to add water, so it may indeed be lead/calcium.

Older vehicles with voltage regulators set at about 14.0 volts simply will not fully charge lead/calcium or hybrid batteries. Stories abound of cars with older regulators leaving their owners stranded on cold mornings shortly after a "new, improved, maintenance-free" battery was installed. Even two weeks of sitting in the garage, with no load other than the electric clock and burglar alarm, can discharge a battery if the voltage regulator prevented it from being properly charged.

The challenge is particularly severe in the case of foreign manufacturers. Many firms are so certain, and so proud, of their engineering expertise that they have declined to modernize their specifications to meet present battery specifications. Bosch, for example, still teaches its "factory-trained" service technicians that 13.8 volts is enough. As late as 1992 the Product Support Manager of their Automotive Service Division wrote (3) that "13.6-13.8 VDC may in fact be adequate", and that "a fully charged battery cannot be charged with 14 VDC or higher. Doing so will cause the battery to be overheated and damaged".

Only slightly contradicting him is a statement from Bosch's Customer Relations Representative (4) that "the alternator and voltage regulator should charge between 13.8 and 14.2 volts". This representative also recommended a local Bosch Authorized Service Center, who assured me that "13.7 volts is enough".

 
Applescruffs said:
yup...read this...quickly copied from a website chosen totally at random...

he hybrid battery is more resistant to deep cycling than the lead/calcium, but is still not as good in this respect as the original lead/antimony style. Most cars supplied with hybrid batteries have their voltage regulators set to 14.3 volts, although it is reported that the higher 14.8 volt setting of GM cars does no harm if the water level is checked regularly.

A fourth type, the "gel cell", has appeared in automotive use. Early reports were that its manufacturer recommended charging at 13.8 to 14.1 volts (2), suggesting it used hybrid chemistry. However, it also does not allow the user to add water, so it may indeed be lead/calcium.

Older vehicles with voltage regulators set at about 14.0 volts simply will not fully charge lead/calcium or hybrid batteries. Stories abound of cars with older regulators leaving their owners stranded on cold mornings shortly after a "new, improved, maintenance-free" battery was installed. Even two weeks of sitting in the garage, with no load other than the electric clock and burglar alarm, can discharge a battery if the voltage regulator prevented it from being properly charged.

The challenge is particularly severe in the case of foreign manufacturers. Many firms are so certain, and so proud, of their engineering expertise that they have declined to modernize their specifications to meet present battery specifications. Bosch, for example, still teaches its "factory-trained" service technicians that 13.8 volts is enough. As late as 1992 the Product Support Manager of their Automotive Service Division wrote (3) that "13.6-13.8 VDC may in fact be adequate", and that "a fully charged battery cannot be charged with 14 VDC or higher. Doing so will cause the battery to be overheated and damaged".

Only slightly contradicting him is a statement from Bosch's Customer Relations Representative (4) that "the alternator and voltage regulator should charge between 13.8 and 14.2 volts". This representative also recommended a local Bosch Authorized Service Center, who assured me that "13.7 volts is enough".

Click to expand...

That all relates to charging voltages which, as any sensible person knows, bear no relation to the resting voltage of a regular lead/acid battery.
 
13.1V is fine if taken off charge not long before.
It's a bit high if still at that after overnight without a charger connected, if that's what you are saying. 12.8V would be good.
Lots of things can cause low voltage but high voltage can really only come from high temperature and/or high electrolyte specific gravity.
Is it in a warm place? 35 deg would add about 0.2V.
Alternatively 13.1V at 25 deg suggests s.g of 1.300 which is very high. Most batteries are 1.260-1.280.
Can you check the s.g. do you have a hydrometer?
Have you let the electrolyte level get very low? That increases the s.g.
Much nicer situation than low voltage anyway!
 
[QUOTE=pvb;3095760]That all relates to charging voltages which, as any sensible person knows, bear no relation to the resting voltage of a regular lead/acid battery.[/QUOTE]


You think I'm a sensible person?? "how very dare you !" ;¬)

Let's leave it as 13.1v is better than 3.1v eh ??
 
Applescruffs said:
So where does that leave our original poster?

Confused?...not arf !!!
Click to expand...

Probably. So do you think your contribution based on misreading a website has helped?
There seems to be something about batteries that makes everyone think they can be an expert. I had 10 years in a technical function with a major L/A battery manufacturer and there is still plenty I don't know, but some of the b*lls spouted on here makes me despair!
Not particularly you, you just picked the wrong moment to add the last straw! :o
 
I would not worry too much about a .1 or .2
If you want to be really pedantic about it you have to use an industrially accurate meter and check each cell individually for acid content and specific gravity and a voltage of 2.109 to 2.201 volts.
Which on a standard run of the mill boat battery of course you can't.
If with a Good and to get a good meter you will have to pay £60 or more.
Any where between 12.6 and 12.9v after it has been left isolated for 6 hours is a "good Battery and it will do the job if it doesn't then Simples it not taking/holding a good charge get rid and re- place.
And if it was a good I mean by good make it will still perform.
Just don't expect too much.
ie run all your lights and TV and gizmo's for 6 to 8 hrs over evening and night and then expect it to start a 6cyl 300hp turbo diesel at 10am the next day.:rolleyes:
 
Sorry for being a downer but...
I'm afraid I picked this particular post to make an experiment and to make a point and play devils advocate....

In good faith someone will post a problem and then ,someone like me, will Google a reply and post it as gospel..the original poster will have no clue as to who is genuine , as you appear to be, and who is not , obviously me!.

I have followed many similar posts and they all follow exactly the same pattern, usually ending up with two people debating the minutiae of some totally insignificant issue and completely ignoring the point of the original post...sounding familiar?

I question who these forums are actually benefiting? Do any of the original posters actually take any advice given..or just get so totally confused and p*ssd off that they go else where. That's my next study...

Sorry that you had to met me in this way... but I hope that you can see my point.

All the best and no bad feelings?

R.
 
duncan said:
Not having used the boat for some time I put the main battery onto a 20A 'smart charger' for a couple of days.

It is basically a coach battery - 1000CCA, 180Ahr calcium technology designed for heavy loads and cycles.

Returning I was told it was fully charged.

On the boats instruments it was showing 13.1v, which I put down to it being 'hot' and expected it to drop back to 12.8v over the next few hours. Instantly started the engine, ran a couple of hours to Yarmouth and it still showed 13.1v.

Next morning it still showed 13.1v........

Has the charger done a really good job.......or is this an indication of a problem?

(I trust the instrument readings - more than one say the same thing and have been accurate for years).
Click to expand...


Happy Days!
 
Applescruffs said:
Sorry for being a downer but...
I'm afraid I picked this particular post to make an experiment and to make a point and play devils advocate....

I question who these forums are actually benefiting? Do any of the original posters actually take any advice given..or just get so totally confused and p*ssd off that they go else where. That's my next study

R.
Click to expand...

They have helped me many, many times. But then I've been getting good advice here for about seven years, rather than your seven months. So hang around, you may learn something :eek:
 
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