Charging batteries

[Kalapattar]

Hi! According to my battery monitor reading my 75a alternator is charging at 12.8v and 0.1 amp! Is that ok? Ta!

[LadyG]

Are your batteries stuffed full?

As I understand it the batteries make their demand on the alternator, which can never output the maximum, eg 75amp, if the batteries are reasonably healthy. 

Others willbe along soon.

They will want to know what charging arrangements you have and how much you are using, also battery configuration etc etc.

Edited November 28, 2020 by LadyG

[Kalapattar]

I’m going to replace my batteries asap!

 

Thanks for your reply!?

[Chewbacka]

My alternator is manufactured to give a max voltage of 14.4v, and does not reduce back to a float voltage once the batteries are full.  So a voltage as low as 12.8v sounds like you either have some form of smart alternator controller which has a very low float voltage or more probably a knackered alternator.

[Slim]

No, not right. First impression is that your alternator is just not charging. When you start your engine and you give it a few revs, say 1500 to 2000 for a few seconds does your charge (ignition) light go out? It's a starting point

[Bod]

What is your battery monitor?

Do you have any other means of checking the battery voltage.  Both whilst the engine is running and not running?

Do you have any solar power arrangements?

All questions that need answers, to allow correct advice to be given.

 

Bod.

[Richard10002]

1 hour ago, Kalapattar said:

Hi! According to my battery monitor reading my 75a alternator is charging at 12.8v and 0.1 amp! Is that ok? Ta!

I’ll repeat the question regarding your battery monitor.

 

What is the make and model?

 

The concern is that it might not be a “battery monitor”.... it might be a solar controller, or a reading on an inverter, or something else that isn’t a battery monitor.

[Kalapattar]

1 hour ago, Chewbacka said:

My alternator is manufactured to give a max voltage of 14.4v, and does not reduce back to a float voltage once the batteries are full.  So a voltage as low as 12.8v sounds like you either have some form of smart alternator controller which has a very low float voltage or more probably a knackered alternator.

I have an Adverc 

[Tony Brooks]

As long as the amps reading is correct then I agree with those who said it sounds like the alternator has a problem - blown diodes.

[ditchcrawler]

Back to basics, When you turn the key on before starting the engine is the "ignition" or charge indicator light on.  Once the engine is running does this light go out?

[dmr]

14.8v is maybe just a little high, but totally normal if you have Trojans or other "proper" batteries. Also the Adverc (alternator controller) does temperature compensation so a higher voltage is expected in cold weather.

The 0.1amp is wrong, how are you measuring this?....do you mean the Adverc current/voltage DCM thing? Either the alternator is wrong or your current monitor is wrong. Its unlikely to be a battery fault, but if they are not getting charged they will be unhappy. Do your lights and other 12 volt stuff work ok?

 

.................Dave

[Richard10002]

8 hours ago, Kalapattar said:

I have an Adverc 

From your previous post on batteries, earlier this month, it looks like you dont have a battery monitor, you were expecting solar to keep up with your use, and you suggested that you were running your engine for a couple of hours each day, to keep them full. Whilst there is probably something wrong with the reading of 0.1A, it is entirely possible that your batteries are as flat as a pancake, and as dead as a dodo.

 

It will still be interesting to know what is providing you with the voltage and Current flow information?

 

For reference, at some stage, you will need to spend about a hundred quid on a NASA BM1 or BM2, or almost £200 on a Victron BM712, or similar. With a proper monitor and a bit more knowledge, you will keep running into power supply issues.

[blackrose]

14 hours ago, Kalapattar said:

I’m going to replace my batteries asap!

 

Thanks for your reply!?

 

Don't do that until you've fingered out what's going on and you have a reliable way of monitoring the batteries. Otherwise you might just knacker the new set straight away.

Edited November 29, 2020 by blackrose

[Tony Brooks]

6 hours ago, Richard10002 said:

From your previous post on batteries, earlier this month, it looks like you dont have a battery monitor, you were expecting solar to keep up with your use, and you suggested that you were running your engine for a couple of hours each day, to keep them full. Whilst there is probably something wrong with the reading of 0.1A, it is entirely possible that your batteries are as flat as a pancake, and as dead as a dodo.

 

It will still be interesting to know what is providing you with the voltage and Current flow information?

 

For reference, at some stage, you will need to spend about a hundred quid on a NASA BM1 or BM2, or almost £200 on a Victron BM712, or similar. With a proper monitor and a bit more knowledge, you will keep running into power supply issues.

I thought that Adverk marketed a battery monitor under their own name so after the OP was asked about his battery monitor he replied that it was an Adverk. I took this at face value. If he really meant he has an Adverk alternator controller then we need to know has the original alternator controller been left working or has it been removed/disabled. I understand from posters here that it can totally replace the normal regulator.

 

If the normal regulator is still in place and working then my original answer stands, most likely a diode or two down. If the Adverk is doing all the work then I still feel its diodes but am far less sure because i have no experience of that setup.

 

If the OP is using a multimeter to measure amps and its not a clamp type I suspect its operator error and possibly the meter's internal shunt has been burned out.

 

If he has an onboard ammeter I suspect it may be measuring engine battery charging current, not alternator output or domestic battery charging current. If so the OP's diagnosis of faulty batteries may well be correct and the domestic charging current has not been measured or reported.

 

[Slim]

1 hour ago, Tony Brooks said:

I thought that Adverk marketed a battery monitor under their own name so after the OP was asked about his battery monitor he replied that it was an Adverk. I took this at face value. If he really meant he has an Adverk alternator controller then we need to know has the original alternator controller been left working or has it been removed/disabled. I understand from posters here that it can totally replace the normal regulator.

 

If the normal regulator is still in place and working then my original answer stands, most likely a diode or two down. If the Adverk is doing all the work then I still feel its diodes but am far less sure because i have no experience of that setup.

 

If the OP is using a multimeter to measure amps and its not a clamp type I suspect its operator error and possibly the meter's internal shunt has been burned out.

 

If he has an onboard ammeter I suspect it may be measuring engine battery charging current, not alternator output or domestic battery charging current. If so the OP's diagnosis of faulty batteries may well be correct and the domestic charging current has not been measured or reported.

 

Back in post 5 I asked a basic question regarding the charge (ignition) light. Ditchcrawler asked a similar one in post 9. To date no answers.

I assumed the OPs reference to an Adverc was to a charge controller not a meter. I have an Adverc charge controller and if wired according to the manufacturers instructions the original regulator is left in place and remains as a fall back. All the wiring goes back to the Adverc via a multipin connector. If this plug is removed or if the unit fails control reverts to the alternators built in control (assuming A127 or similar.)

At the beginning of the year I had a very similar problem. Charge light stayed on with readings of 12.8v  0a. It was no more than a disconnected ignition warning light wire from the alternator.   

[ditchcrawler]

If the OP is reading the voltage and current from the solar controller with the engine running the reading of current is probably correct as the solar charging would have shut down due to the high voltage from the alternator and the alternator current doesn't flow through the solar controller 

[Chewbacka]

5 minutes ago, ditchcrawler said:

If the OP is reading the voltage and current from the solar controller with the engine running the reading of current is probably correct as the solar charging would have shut down due to the high voltage from the alternator and the alternator current doesn't flow through the solar controller 

No matter the charging method, a battery voltage of 12.8v is too low for charging.  Something is wrong.

Edited November 29, 2020 by Chewbacka

[enigmatic]

1 hour ago, Slim said:

At the beginning of the year I had a very similar problem. Charge light stayed on with readings of 12.8v  0a. It was no more than a disconnected ignition warning light wire from the alternator.   

I had that problem this week! As soon as I put the warning light bulb properly into its slot the alternator started easily, with a nice big voltage jump showing on voltemeters, solar controllers etc

 

1 hour ago, Chewbacka said:

No matter the charging method, a battery voltage of 12.8v is too low for charging.  Something is wrong.

Presumably the OP also sees around 12.8v when their engine is not running...

[Richard10002]

6 hours ago, Tony Brooks said:

I thought that Adverc marketed a battery monitor under their own name so after the OP was asked about his battery monitor he replied that it was an Adverk. I took this at face value.

 

You are, of course, correct

 

https://adverc.co.uk/collections/adverc-battery-systems/products/adverc-dcm

 

Like others, I didn't know that Adverc sell a monitor, so assumed he was referring to a controller. I also wonder if he is getting his info from an inverter display, or a solar controller, or something else that isnt an actual battery monitor.

 

The OP is sparse with info, which makes it difficult to help him.

[Tony Brooks]

2 hours ago, Richard10002 said:

You are, of course, correct

 

https://adverc.co.uk/collections/adverc-battery-systems/products/adverc-dcm

 

Like others, I didn't know that Adverc sell a monitor, so assumed he was referring to a controller. I also wonder if he is getting his info from an inverter display, or a solar controller, or something else that isnt an actual battery monitor.

 

The OP is sparse with info, which makes it difficult to help him.

Your last sentence sums it all up. Ask for help, get asked to provide more info so a sensible answer can be given and then either ignore the requests or refuse to answer. Even "I don't really know" would be better than silence.

 

If this is a single alternator boat its even possible its a charge splitter fault or the bug switch is in the wrong position.

[Chewbacka]

15 minutes ago, Tony Brooks said:

Your last sentence sums it all up. Ask for help, get asked to provide more info so a sensible answer can be given and then either ignore the requests or refuse to answer. Even "I don't really know" would be better than silence.

 

If this is a single alternator boat its even possible its a charge splitter fault or the bug switch is in the wrong position.

I have noticed that many ‘new’ people don’t realise how quick this place is, and they sometimes take a day or two before looking again.  Probably best if we quietly wait, as if there are too many ‘observations’ that the op is not answering they be frightened away.......

[Kalapattar]

Hi! Thanks for all your replies! I’m going to change drive belt. It may be that.

in have nasa monitor and Adverc

my output isn’t much as I only use it for lights , water pump and light on fridge which I run on gas

[LadyG]

16 hours ago, Chewbacka said:

I have noticed that many ‘new’ people don’t realise how quick this place is, and they sometimes take a day or two before looking again.  Probably best if we quietly wait, as if there are too many ‘observations’ that the op is not answering they be frightened away.......

Well now we know, OP had a plan all along.

[Tony Brooks]

13 minutes ago, Kalapattar said:

Hi! Thanks for all your replies! I’m going to change drive belt. It may be that.

in have nasa monitor and Adverc

my output isn’t much as I only use it for lights , water pump and light on fridge which I run on gas

 

And on the basis of what you have told us it may well not be that unless you have declined to tell us how slack the belt is or how badly its shredding.

 

The following is not supposed to be critical of the OP (apart from not answering questions) but is intended to explain the fault finding process. its not the OP's fault if at the moment he does not have much idea about the info we need or how his system works

 

It seem to me that you are taking the "lets change random items and hope it cures the problem" approach to fault finding rather than getting to understand the system and working out a logical test sequence. If I am correct your way leads to unnecessary expense - batteries and now drive belt. What next? New alternator, new monitor, new warning lamp bulb - oh dam, I just found this wire has fallen off.

 

You have been asked about the charge warning lamp - twice I think, yet no answer. That is the first step of charge system fault finding.

 

Only late in the topic do we find you are probably using a battery monitor plus and alternator controller and that the amps and volts reading probably come from a reliable on these scales monitor.

 

If the warning lamp is operating normally and the belt is in fair condition and tension then I still think the problem is likely to be the alternator but can't be sure unless a test sequence is followed. Certainly the current quoted suggests very fully charge batteries or a faulty alternator/drive while the voltage suggests exceptionally discharged batteries. Obviously both state of charge conclusions can't be correct so the state of charge should be ignored and the fault looked for else where - hence alternator or belt. I hope its the belt but fear it may not be.

 

 

[Kalapattar]

Oops! Sorry I didn’t reply over the weekend! I tend to leave my messaging, Facebook etc alone at weekends and see what else is out there.

my lights do go out suggesting alternator is working ok! It is a process of elimination, just how the way engines and electrics work. However, I’m not an electrician! What does  0.1 amp suggest on my nasa monitor please?