What have i done to my batteries?

[Murflynn]

I surprised myself the other week. 

 

I have 4 x 110Ah lead acid leisure batteries on my electric powered launch which I keep charged by a PACO automatic '7 stage' 20A charger.  When I'm cruising I watch the charger's 7 stage status indicator LEDs, and the batteries achieve the final stage that is described as 'fully charged' after about 12 hours. 

 

Over the winter the battery volts have been regularly dropping to 12.2v within a week or so, and I have used the charger typically for 24 hours to get back up to float at 13.5v.  I expected to have to replace the batteries in the spring.  

 

The last time I charged up I left the charger on for 4 days and, when I checked both the voltmeters on the boat, they were reading 16.1v. 

 

I have never seen the volts rise above 14.6v before with this charger.   The charger is described as 'fit and forget' and is recommended for keeping motorhome batteries charged up over the winter.

 

The upside is that the batteries have held at 12.8v for 2 weeks already so I assume they are in good condition.

 

Any comments?

[dmr]

5 hours ago, Mike the Boilerman said:

 

"Volterage" would be the equivalent, Shirley?

Voltaireage would be more historically accurate ?

 

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

[cuthound]

1 hour ago, Murflynn said:

I surprised myself the other week. 

 

I have 4 x 110Ah lead acid leisure batteries on my electric powered launch which I keep charged by a PACO automatic '7 stage' 20A charger.  When I'm cruising I watch the charger's 7 stage status indicator LEDs, and the batteries achieve the final stage that is described as 'fully charged' after about 12 hours. 

 

Over the winter the battery volts have been regularly dropping to 12.2v within a week or so, and I have used the charger typically for 24 hours to get back up to float at 13.5v.  I expected to have to replace the batteries in the spring.  

 

The last time I charged up I left the charger on for 4 days and, when I checked both the voltmeters on the boat, they were reading 16.1v. 

 

I have never seen the volts rise above 14.6v before with this charger.   The charger is described as 'fit and forget' and is recommended for keeping motorhome batteries charged up over the winter.

 

The upside is that the batteries have held at 12.8v for 2 weeks already so I assume they are in good condition.

 

Any comments?

 

Many "smart" chargers incorporate a periodic equalising charge function (perhaps for 1 hour per month at 15.5 to 16 volts). Maybe yours has this feature?

[WotEver]

On 08/03/2020 at 11:34, dmr said:

My old man was an electrician and always used the term amperage

That don’t make ‘im right

19 hours ago, cuthound said:

 

Many "smart" chargers incorporate a periodic equalising charge function (perhaps for 1 hour per month at 15.5 to 16 volts). Maybe yours has this feature?

That would certainly be my guess. 

[dmr]

1 minute ago, WotEver said:

That don’t make ‘im right

You measure volts with a voltmeter and amps with an ammeter, NOT a currentometer ?

 

Where did the P go in ammeter?

 

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

[WotEver]

3 minutes ago, dmr said:

You measure volts with a voltmeter

Voltage Shirley. 

[dmr]

4 minutes ago, WotEver said:

Voltage Shirley. 

you mean voltage as in amperage ?

 

and remember that voltage divided by amperage is ohmage.,

 

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

[WotEver]

49 minutes ago, dmr said:

you mean voltage as in amperage ?

 

and remember that voltage divided by amperage is ohmage.,

 

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

And some multiplication gets you wattage. 

[Murflynn]

20 hours ago, cuthound said:

 

Many "smart" chargers incorporate a periodic equalising charge function (perhaps for 1 hour per month at 15.5 to 16 volts). Maybe yours has this feature?

 

yep, thanks  - found it:

 

https://www.pacopower.com/automatic-charging-12v-20a-7-stage-battery-charger-15.html

 

pity the manual didn't explain. 

[cutandpolished61]

On ‎08‎/‎03‎/‎2020 at 11:16, Mike the Boilerman said:

 

This is the root of your problem, especially given the incorrect calibration of the battery charger means you were stopping charging when the charge voltage was at 13.8V.

 

Received wisdom on this board is that you should set your charger to charge at 14.4V to 14.8V then monitor the charge current. When the 14.4V is reached you must CONTINUE CHARGING until the charge current falls to a value which is 1% of the battery badge capacity. (I know the units/dimensions don't match but ignore that. 400AH capacity, charge until the current has fallen to 4A.)

 

Having said all that, it take about 8 hours to do this so few people actually do it. Those who do, make a bloody nuisance of themselves out on the cut running their engines or gennies for hours on end and ruining a nice sunny peaceful day for everyone else, so maybe just buy new batteries every year or two.

 

 

 

 

Problem with my charger is that I can't set a maximum charge. This thing keeps on bulk charging. So i'm forced to switch it off before the float start charge to avoid cooking them.

[dmr]

3 minutes ago, cutandpolished61 said:

Problem with my charger is that I can't set a maximum charge. This thing keeps on bulk charging. So i'm forced to switch it off before the float start charge to avoid cooking them.

It don't work like that. Bulk charge is not (usually) an option that the charger controls, it just means that the batteries can take all the current the charger can produce.

As the batteries get fuller they can accept less current and at some stage can take less than the charger can produce and so the charger now just provides whatever current is needed at a fixed voltage. The current should fall to very little once the batteries are fully charged, if it doesn't then there is a bad battery.

 

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

[ditchcrawler]

21 minutes ago, cutandpolished61 said:

Problem with my charger is that I can't set a maximum charge. This thing keeps on bulk charging. So i'm forced to switch it off before the float start charge to avoid cooking them.

How do you decide when they are charged and switch them off. Are you on a shore supply

[cutandpolished61]

15 minutes ago, ditchcrawler said:

How do you decide when they are charged and switch them off. Are you on a shore supply

I charge them with a 40 amp battery charger powered by a generator.

32 minutes ago, dmr said:

It don't work like that. Bulk charge is not (usually) an option that the charger controls, it just means that the batteries can take all the current the charger can produce.

As the batteries get fuller they can accept less current and at some stage can take less than the charger can produce and so the charger now just provides whatever current is needed at a fixed voltage. The current should fall to very little once the batteries are fully charged, if it doesn't then there is a bad battery.

 

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

Thanks Dave but how do I avoid accidentally overcharging the batteries.

[Alan de Enfield]

4 minutes ago, cutandpolished61 said:

Thanks Dave but how do I avoid accidentally overcharging the batteries.

If you have a 'smart' charger then it cannot overcharge.

The battery demands a certain current and the charger supplies it.

As the battery becomes 'more charged' the battery demands less and the charger supplies a lower current,

The battery become even 'more charged', demands less so the charger provides less.

 

There is nothing for you to do, BUT, your problem is that you are using a generator and I'm sure you don't run it for 4 or 5 hours every day and 8 hours at weekends (which is quite probably what you need to do)

[cutandpolished61]

4 minutes ago, Alan de Enfield said:

If you have a 'smart' charger then it cannot overcharge.

The battery demands a certain current and the charger supplies it.

As the battery becomes 'more charged' the battery demands less and the charger supplies a lower current,

The battery become even 'more charged', demands less so the charger provides less.

 

There is nothing for you to do, BUT, your problem is that you are using a generator and I'm sure you don't run it for 4 or 5 hours every day and 8 hours at weekends (which is quite probably what you need to do)

Röhr Car Battery Charger 45 Amp 12V / 24V Dfc-50P Intelligent Turbo/Trickle    This is the charger i'm using. It says overcharging protection on the tin.

[ditchcrawler]

17 minutes ago, cutandpolished61 said:

I charge them with a 40 amp battery charger powered by a generator.

 

But how do you decide they are full and switch it off?

 

[Alan de Enfield]

2 minutes ago, cutandpolished61 said:

Röhr Car Battery Charger 45 Amp 12V / 24V Dfc-50P Intelligent Turbo/Trickle    This is the charger i'm using. It says overcharging protection on the tin.

That is not what you need it is only "low" or "High" charge rate

 

You need something that alters the output current to suit and is adjustable to suit your type of batteries (FLA / Sealed / Unsealed/ GSM etc etc =-- they all require slightly different voltages)

Not suggesting this particular one, but something like it :

 

https://www.marinesuperstore.com/batteries-power-chargers/alternators-chargers/sterling-pro-charge-ultra?variant=99314781&utm_source=google_shopping&utm_medium=pcn&utm_term=PRO+CHARGE&utm_campaign=MSS&gclid=Cj0KCQjw9ZzzBRCKARIsANwXaeJZFnG6-ScWVf4NYhjZxrgpjnxN5fTtHEK53FeJ7tbuxzFuCZbiD7MaApi8EALw_wcB

 

 

[dmr]

21 minutes ago, cutandpolished61 said:

I charge them with a 40 amp battery charger powered by a generator.

Thanks Dave but how do I avoid accidentally overcharging the batteries.

Its pretty hard to overcharge batteries, under charging is the usual problem.  If you are out cruising its extremely  unlikely that you will overcharge. If you are connected to full time mains electricity then you will need a charger that goes into float mode when it feels the batteries are fully charged. If you have a way of measuring current then you can confirm this is working ok. Charge current should fall to slowly to few amps then the charger should indicate float (a LED of sort sort) and the current should fall to almost zero. Float mode puts in just enough to keep them topped up (with a bit of luck)

 

Most chargers don't get the float thing exactly right so when you go cruising you will likely find the charger going into float before the batteries are fully charged resulting in under-charging.

 

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

[cutandpolished61]

8 minutes ago, Alan de Enfield said:

That is not what you need it is only "low" or "High" charge rate

 

You need something that alters the output current to suit and is adjustable to suit your type of batteries (FLA / Sealed / Unsealed/ GSM etc etc =-- they all require slightly different voltages)

Not suggesting this particular one, but something like it :

 

https://www.marinesuperstore.com/batteries-power-chargers/alternators-chargers/sterling-pro-charge-ultra?variant=99314781&utm_source=google_shopping&utm_medium=pcn&utm_term=PRO+CHARGE&utm_campaign=MSS&gclid=Cj0KCQjw9ZzzBRCKARIsANwXaeJZFnG6-ScWVf4NYhjZxrgpjnxN5fTtHEK53FeJ7tbuxzFuCZbiD7MaApi8EALw_wcB

 

 

Had a look at these ones yesterday and might get one. Will the charge rate reduce with the one i'm using now when the battery is full or will it keep charging until they pop

[mrsmelly]

5 minutes ago, cutandpolished61 said:

Had a look at these ones yesterday and might get one. Will the charge rate reduce with the one i'm using now when the battery is full or will it keep charging until they pop

They won't go pop but will remain undercharged. 

Short answer is you need all at once

A new set of batteries

A decent fit for purpose charger, and thirdly and of paramount importance a battery monitoring system. My favourite is a nasa bm2 but others are available. Then immediately instigate a good charging regime. 

[Alan de Enfield]

45 minutes ago, mrsmelly said:

They won't go pop but will remain undercharged. 

Short answer is you need all at once

A new set of batteries

A decent fit for purpose charger, and thirdly and of paramount importance a battery monitoring system. My favourite is a nasa bm2 but others are available. Then immediately instigate a good charging regime. 

 

And, either cruise 4+ hours per day, or get a mooring with a shore-line connection, or buy shares in a petrol company to allow you to run the generator for sufficient hours per day, or invest in 500w of solar panels, or, do a bit of everything.

[cutandpolished61]

3 minutes ago, Alan de Enfield said:

 

And, either cruise 4+ hours per day, or get a mooring with a shore-line connection, or buy shares in a petrol company to allow you to run the generator for sufficient hours per day, or invest in 500w of solar panels, or, do a bit of everything.

Will go definitely for over the top solar, hate this genny running twice a week.

 

Currently running for 5 hrs and showing 14.4 volt.

[Alan de Enfield]

1 minute ago, cutandpolished61 said:

Will go definitely for over the top solar, hate this genny running twice a week.

 

Currently running for 5 hrs and showing 14.4 volt.

Running the Jennifer twice a week is not enough.

 

14.4 volts (measured on which device ? & is it accurate ?) and at what current ?

[mrsmelly]

As Alan says, 14.4 voltage is good but you need the amps to be down around 4 for about an hour also. The only easy way to find that out is invest in a bit of kit such as a nasa bm or victron 700 series or similar. Or a decent voltmeter thingy and amp meter thingy. 

Edited March 10, 2020 by mrsmelly

[cutandpolished61]

39 minutes ago, mrsmelly said:

As Alan says, 14.4 voltage is good but you need the amps to be down around 4 for about an hour also. The only easy way to find that out is invest in a bit of kit such as a nasa bm or victron 700 series or similar. Or a decent voltmeter thingy and amp meter thingy. 

Thanks for all your advice this afternoon. Much appreciated.