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Battery charging


Timx

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Hi,in lock down and now in front of a stoppage  I usually charge my batteries by an hour or so a day, using the engine, them after two or three days go for a cruise slowly to empty rubbish , pump out maybe, get water etc, and that takes batteries to 90 percentish , then once a week, go on a marina electric bollard for an overnight charge, taking my amps down to less then 1 percent.

I have three 230 ah AGM batteries, which are about four years old now, so I thought all this idling around, I usually cruise cruise cruise as a cc, I would get a generator to stop running the engine for no reason. Eventually got one off e bay for £575.  EU 201 , 

tried it for first time yesterday, it sounded quite loud at first, but gradually got quieter, until so quiet, I checked outside it was still there!

however the voltage kept rising as to be expected , but it started going over 14.7 volts charging. But it had been charging for nearly two hours so I stopped it probably 90 pc charged, 24 amps going in on 690ah batteries.

I have never really noted the voltage when charging through land line, but as I am now doing my weekly land line charge, I am noticing differences.

when the amp counter goes to around 25 amps the charger usually goes to float, but as I write it has only just gone to float, at 6amps?

I have a victron 120 amp charger.

is it safe to charge my AGMs over 14.7 v, ? And why on landline does it not go that high, 14.6 this time but not checked before

is the power supply irreverent, ie second hand Honda generator 

will my charger inverter regulate any irregular input.

Can I knacker my batteries by using a generator through my victron charger if it goes above 14.7 v

Should I just trust the charger and forget it.

on float now and voltage decreasing.

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My AGMs are charged at 14.8v. That’s what my victron solar controller was set to by Kevin at onboard energy when he fitted the system. It also states 14.8v on a sticker on the batteries which are 125ah of which I have four.

 

 

edited to reflect Tony’s comment below.

Edited by Jinna
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3 minutes ago, Jinna said:

AGMs should be charged at 14.8v. That’s what my victron solar controller was set to by Kevin at onboard energy when he fitted the system. It also states 14.8v on a sticker on the batteries which are 125ah of which I have four.

Be a bit wary of that advice. Whilst its true that at least one supplier says this there are or was an AGM technology that had a lower maximum voltage. The advice shoudl be to use the value state by the battery manufacturer.

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13 hours ago, Timx said:

 

is it safe to charge my AGMs over 14.7 v, ? And why on landline does it not go that high, 14.6 this time but not checked before Check the battery manufacturer's spec

is the power supply irreverent, ie second hand Honda generator I would have thought the power supply is irrelevant when it comes to 12v charger output

will my charger inverter regulate any irregular input. I use a honda generator direct to a standalone Sterling battery charger and it's fine, so if you're going through a Victron inverter it should smooth out any irregularities - but I guess it depends on the Victron - you don't say what model it is? Have you set the victron charger for your battery type?

Can I knacker my batteries by using a generator through my victron charger if it goes above 14.7 v That would depend on the max charge voltage stated by the battery manufacturer.

Should I just trust the charger and forget it. No, do your homework.

 

 

The other things you might need to consider (if you haven't) are storage of petrol and also the generator when it's still got fuel in the tank. Where are you storing them? Also the risk of CO. Where are you running the generator? 

Edited by blackrose
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14 hours ago, Timx said:

 

is the power supply irreverent, ie second hand Honda generator 

will my charger inverter regulate any irregular input.

Can I knacker my batteries by using a generator through my victron charger if it goes above 14.7 v

 

Generator or shore power shouldnt make any difference.

 

Your charger will be set to a particular charging profile, and should regulate to this profile.

 

You might knacker your batteries if they are being charged at too high a voltage.

 

What brand and model are your batteries? This info might help someone identify the correct charge profile.

 

Where are you getting the voltage and amps readings from? The charger inverter screen? A battery monitor? Which make and model? or could it be a solar charge controller/monitor?

 

I ask because when my 240V charger screen shows 14.8V but, because of voltage drop, the actual voltage at the batteries is 14.5V, (or so). 

 

My understanding was that AGMs generally shouldn't be charged above about 14.4V, (I could be wrong based on some of the above advice/info).

 

Do you know how to change the charge profile on your Victron... which model is it?

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16 hours ago, Timx said:


Hi,in lock down and now in front of a stoppage  I usually charge my batteries by an hour or so a day, using the engine, them after two or three days go for a cruise slowly to empty rubbish , pump out maybe, get water etc, and that takes batteries to 90 percentish , then once a week, go on a marina electric bollard for an overnight charge, taking my amps down to less then 1 percent.

I have three 230 ah AGM batteries, which are about four years old now, so I thought all this idling around, I usually cruise cruise cruise as a cc, I would get a generator to stop running the engine for no reason. Eventually got one off e bay for £575.  EU 201 , 

tried it for first time yesterday, it sounded quite loud at first, but gradually got quieter, until so quiet, I checked outside it was still there!

however the voltage kept rising as to be expected , but it started going over 14.7 volts charging. But it had been charging for nearly two hours so I stopped it probably 90 pc charged, 24 amps going in on 690ah batteries.

I have never really noted the voltage when charging through land line, but as I am now doing my weekly land line charge, I am noticing differences.

when the amp counter goes to around 25 amps the charger usually goes to float, but as I write it has only just gone to float, at 6amps?

I have a victron 120 amp charger.

is it safe to charge my AGMs over 14.7 v, ? And why on landline does it not go that high, 14.6 this time but not checked before

is the power supply irreverent, ie second hand Honda generator 

will my charger inverter regulate any irregular input.

Can I knacker my batteries by using a generator through my victron charger if it goes above 14.7 v

Should I just trust the charger and forget it.

on float now and voltage decreasing.

 

Very much depends on the brand of AGM.

 

My Lifeline AGMs can be equalised at up to 15.5 volts, but they are very much a premium brand.

 

Best to look at the manufacturers information to se what voltages to charge and float at.

 

With regard to charging on a generator rather than the mains, providing the charger will.accept the generators output, the charger should behave in exactly the same way.

Edited by cuthound
Clarification
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1 minute ago, Tony Brooks said:

I am not sure the OP has specifically stated that he is using the  generator to power the mains charger. Its just possible he is using the 12V DC output and that is unregulated and will reach 20 volts or more as the charging current drops. not a good idea.

This seems unlikely bearing in mind the sort of charging currents he mentions, and he does specifically say he’s using the Victron charger.

 

To the OP, don’t forget that if it has a temperature sensor, the charger will adjust the charging voltage according to the battery temperature - cold batteries = higher charge voltage. When you run the engine to charge, this probably warms the batteries so that towards the end of the charge, they are warmish. With an external generator the batteries will be stone cold and thus a somewhat higher charge voltage can be expected.

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3 minutes ago, Tony Brooks said:

I am not sure the OP has specifically stated that he is using the  generator to power the mains charger. Its just possible he is using the 12V DC output and that is unregulated and will reach 20 volts or more as the charging current drops. not a good idea.

I'm not sure that he would get 20-30 amps vout of the 12v output on the generator.

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8 hours ago, Tony Brooks said:

Be a bit wary of that advice. Whilst its true that at least one supplier says this there are or was an AGM technology that had a lower maximum voltage. The advice shoudl be to use the value state by the battery manufacturer.

Agree my leoch AGM's say 14.4 v max. 

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5 minutes ago, Alan de Enfield said:

From Alpha batteries

 

 

 

Screenshot (95).png

Sorry Alan,

 

You seem to be suggesting that Detlings batteries can be charged up to 14.6V, according to Alpha. However, unless you know something that some of us may not know, that may, or may not, be correct. Particularly as his batteries "say" 14.4V. My guess is that this is printed on the battery label, (but it's only a guess).

 

For clarity, my post about limiting the voltage to 14.4V was directed to the OP, although I would agree that it was a reply to Detling, so possibly confusing.

 

Are all Pure Lead Carbon batteries AGMs?

 

Are Detlings Leoch AGMs Pure Lead Carbon?

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Thanks for replies, they are Leoch 230 AGM,s had them for 4 years, first time I have used a generator. I went into a marina last night to give them a good charge, and victron bmv 7.2  showed not going over 14.6 v, to charge them down to 1 amp over night. I was worried when after two hours charging with the Honda generator240 outlet it started going over 14.7 v, but it was charged enough for me then anyway. But if I got iced in could I do a long charge, and would it harm the batteries, would the charger regulate it. Should I disconnect at 12.7v or leave it till 12.8v 

Lots  of differing advice

BA2BCD77-0FC5-4EB8-81E0-CA899EAFF0E0.jpeg

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Maybe this will help.

I have 4 x 130 Leoch AGMs and have just dug out the manufacturers spec sheet that I downloaded from the official Website.

"Initial charging current less than 27.0 A at voltage 14.4 - 15.0 V @ 25 degrees coefficent   -30mV / degree c."

Forgive typing but need to do something urgently. Will return to topic later if you have any questions

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12 minutes ago, Slim said:

Maybe this will help.

I have 4 x 130 Leoch AGMs and have just dug out the manufacturers spec sheet that I downloaded from the official Website.

"Initial charging current less than 27.0 A at voltage 14.4 - 15.0 V @ 25 degrees coefficent   -30mV / degree c."

Forgive typing but need to do something urgently. Will return to topic later if you have any questions

That suggests constant current charging as I would expect for the first charge but we tend to do constant voltage charging even if chargers mess with it. If its not on the data sheets I would be onto Leoch and asking for the maximum routine charging voltage.

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Ok I have same victron the agm charge profiles are set up for victron agm batteries , there are 2 options either 14.7 v absorb or 14.4 v absorb these are set either by puter via usb link or by dip switches inside the case on upper right . Check the profile of your battery and whether your victron has temp compensation , victron agms should have 14.4 for shallow cycles or if new non compensated , 14.7 is good this time of year if no temp compensation. Some agm like full river want 14.7 nominal.

 

Leoch ones prob 14.4 nominal but this time of year with low temps then 14.7;is good if you don’t have temp compensation. . If you have temp compensation the. 14.4 is prob best , those two options are the only ones for agm , if you need a different voltage you will need to play with other batteries settings unless newer unit which has more options 

 

 

Edited by RufusR
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The manuals for the 12/3000/120 with particular firmwares, (xxxx4xx or xxxx1xx) have tables at 5.5.2 to show the dipswitch settings for the 4 charging profiles available:

 

https://www.victronenergy.com/upload/documents/Manual-MultiPlus-3k-230V-16A--50A-(firmware-xxxx1xx)a-EN-NL-FR-DE-ES-SE.pdf

 

https://www.victronenergy.com/upload/documents/Manual-MultiPlus-3k-230V-16A-50A-(firmware-xxxx4xx)-EN-NL-FR-DE-ES-SE.pdf

 

The 4 Absorption Voltages are 14.1V, 14.7V, 14.4V, and 15.0V

 

It would seem that the OPs charger is set for the 14.7V absorption voltage.

 

He could, if he wishes, change this to 14.4V

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39 minutes ago, ditchcrawler said:

I am not sure how you are going to know if they are 12.7 or 12.8 without disconnecting them

Thanks but I meant whilst-charging ,the voltage creeps up and went over 14.7 v and I wasn’t sure if that was harming the batteries, from other answers it looks like I can charge up to 14.8 v. What made me think twice is that when on once a week hook up the v charge doesn’t  go above 14.6v 

 

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3 hours ago, Tony Brooks said:

That suggests constant current charging as I would expect for the first charge but we tend to do constant voltage charging even if chargers mess with it. If its not on the data sheets I would be onto Leoch and asking for the maximum routine charging voltage.

Think I've found it (in graph form) Continuous charge at around 25 degrees 2.4 v (x 6) = 14 .4v

For info.  Float @ 25 degrees 13.5 -13.8 v

Edited by Slim
incorrect figure quoted
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Thanks for all answers, still not sure, will keep below 14.7 to be safe, when I bought boat, he never went into a marina, and did have a generator, the batteries were , as the boat, seven years old, but the batteries were ballooned and had to be replaced once I started learning things.

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  • 2 weeks later...
19 minutes ago, blackrose said:

I topped up my Trojans today and charged them back up. I was thinking of doing an equalization charge but is now a good time to do it - after topping them up?

 

I think I last did an equalisation charge about 3 months ago.

It would certainly mix the electrolyte up because at the moment its probably suffering a degree of stratification but agood ordinary charge would probably do it as well.

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