Another Battery Question

[MtB]

2 hours ago, mrsmelly said:

Correct. You have deffo something of a problem. For instance we left mooring last week and went offline for 3 nights. We have four 110 a/h batteries. Our inverter is NEVER turned off neither is our fridge, or seperate freezer. We go out around 6pm with fully charged batts and next morning depending on what we did when we returned later in the evening our batts are somewhere between 12.2 and 12.4 at 8 am. These are mains units so superior to tinny 12 volt stuff. Fit new batteries and keep em charged I reckon.

 

 

Bear in mind Mrsmelly runs his engines 26 hours per day to keep his batts properly charged, much to the delight of his neighbours....

 

 

[Johny London]

Ah ha. So "overnite" is really a lot more than just that - it's your whole late afternoon and evening of whatever entertainment you are using.

 

If Mr Smellys batteries are down to 12.2 he's used about 160ah (if his bank is healthy and the usual 4x 100ah which I believe is the case) which is considerable.

 

Personally I never put my tv/hard drive on till 9pm or later - so only three hours use, and with some lighting and my 12v fridge on through the nite that's about all I use, prolly 40a ("overnite"). 

 

Options: Cut down your power usage when off grid. Get some solar. It's still likely the current batteries are fritzed but as you say, see how they are after another recharge from shore power. Replacing without improving your regime will result in the same.

[TheBiscuits]

10 minutes ago, Mike the Boilerman said:

 

 

Bear in mind Mrsmelly runs his engines 26 hours per day to keep his batts properly charged, much to the delight of his neighbours....

 

 

They are all pig sick of his behaviour, apart from the sheepish ones ...

[Dr Bob]

2 hours ago, mrsmelly said:

 

I told you before. I get bored easily.

[Alan de Enfield]

11 minutes ago, Dr Bob said:

I told you before. I get bored easily.

[Guest]

11 hours ago, Nick D said:

Thanks Alan, I did wonder if they are reaching the end of their life although they are only a year old and I think I have managed them appropriately I.e always on a shore line/charger when in the marina, and charged fully each day when we are out.  

 

I don't have a 3a drain when nothing switched on. Overnight, with the inverter, fridge and cooler on it varies between 3-6amps.

My batteries died this week after about 15 months of full time liveaboard use. I was not best pleased as I have looked after them well. They pretty much did a sudden death thing and were not keeping the fridge going overnight as they once did; I suspect a shorted cell in one but my life is too precious to be peeing around with old batteries. The difference with new batteries is amazing and makes me realise how knackered the others had got. It is like fitting new brakes on a car; you thought the old ones were good until you try the new ones..... 

[Guest]

12 hours ago, mrsmelly said:

It could well be your inverter even on standby taking 3 amps without the fridge compressor or owt else running? I had the misfortune on one boat for a short time till I disposed of it of having a stirling combi that sat drawing 4 amps whilst powering nowt. A good inverter sits at around one amp. My present combi sits at 0.3 of an amp until instantly firing up when asked by the fridge or somett. I never turn my combi off and always buy mains stuff. This boat had a 12 volt fridge and a 12 volt freezer fitted on purchase, both working well and now both doing good work on other forum members boats as I replaced with new mains units,  they use less leccy and are bigger and mooooooooooooooooooooooooooocho cheaper to buy. You will find the first twenty years of living aboard are a learning curb re all things living aboard. We found the last ten much better so far as its all fallen into place ?

Never was a truer word spoken.
You quickly find any weaknesses in your boat once you live on it!
I fitted our boat out 15 years ago with a view to living on it one day and thought I had done everything reasonably well. I would do a few things differently if I did another fit out.

[mrsmelly]

8 minutes ago, catweasel said:

Never was a truer word spoken.
You quickly find any weaknesses in your boat once you live on it!
I fitted our boat out 15 years ago with a view to living on it one day and thought I had done everything reasonably well. I would do a few things differently if I did another fit out.

You have hit the nail on the head there Stan. We have lived on 8 boats 3 of which were specificaly built as liveaboards before the present one. The present one was built by people who actualy really did know what they were doing as a full time liveaboard and the attention to detail regarding real life living is superb. No fancy brass or chrome etc but a briliant fitout for living on full time.

[Guest]

7 minutes ago, mrsmelly said:

You have hit the nail on the head there Stan. We have lived on 8 boats 3 of which were specificaly built as liveaboards before the present one. The present one was built by people who actualy really did know what they were doing as a full time liveaboard and the attention to detail regarding real life living is superb. No fancy brass or chrome etc but a briliant fitout for living on full time.

Pump out or cassette? NO! JUST KIDDING!  
It is quite a learning curve, especially when you have been used to having loads of clobber in one of those house things that we sail past these days.  I am learning to become an essentialist ( I hate the word "minimalist") and disposing of items that are redundant. 

[Nick D]

Out of the last four nights, including tonight, two have been on hook up so too early to tell, but I will report back with findings.  Probably need to give it two or three days offshore to see if a peters emerges.

[Dr Bob]

3 hours ago, Nick D said:

Out of the last four nights, including tonight, two have been on hook up so too early to tell, but I will report back with findings.  Probably need to give it two or three days offshore to see if a peters emerges.

Wots Peter got to do with this?

Dont start blaming him!

[TheBiscuits]

1 minute ago, Dr Bob said:

Wots Peter got to do with this?

Dont start blaming him!

I reckon autocolin got to him ...

[Dr Bob]

1 minute ago, TheBiscuits said:

I reckon autocolin got to him ...

We could have done with some autocoolin on the bote today!

[peterboat]

9 hours ago, Dr Bob said:

Wots Peter got to do with this?

Dont start blaming him!

Nowt to do with me Bob I have been away on boat for weekend, got back with 81% left in drive batteries, sun was shining for most of the way back

[MtB]

3 hours ago, peterboat said:

Nowt to do with me Bob I have been away on boat for weekend, got back with 81% left in drive batteries, sun was shining for most of the way back

 

 

Fair weather boater eh?? ?

 

[peterboat]

5 hours ago, Mike the Boilerman said:

 

 

Fair weather boater eh?? ?

 

In my centrally heated, insulated and  double glazed wheelhouse, yup ?

[Nick D]

 

So if I do end up needing to buy anew set of batteries, what is a safe level of voltage beyond which they should not drop?  I can then set a warning alarm on the BMV

[Alan de Enfield]

23 minutes ago, Nick D said:

 

So if I do end up needing to buy anew set of batteries, what is a safe level of voltage beyond which they should not drop?  I can then set a warning alarm on the BMV

There is no correct answer.

 

Everything is a balance of cost of batteries vs life of batteries, vs amount of Ah used vs cost of running your engine to recharge them.

 

The general consensus is that not going below 50% SoC is probably the most economic option.

Do not let your batteries goes below 12.2 volts, and them charge them immediately to as a high a state of charge as you can then with 8+ hours running every few days to get them back to somewhere near 100% SoC

Edited July 8, 2019 by Alan de Enfield

[MtB]

16 minutes ago, Alan de Enfield said:

There is no correct answer.

 

Everything is a balance of cost of batteries vs life of batteries, vs amount of Ah used vs cost of running your engine to recharge them.

 

The general consensus is that not going below 50% SoC is probably the most economic option.

Do not let your batteries goes below 12.2 volts, and them charge them immediately to as a high a state of charge as you can then with 8+ hours running every few days to get them back to somewhere near 100% SoC

 

In addition, the terminal voltage drop according to how much load the batteries are supplying. So setting an alarm at say 12.2v is quite likely to result in the alarm sounding whenever the Webasto starts its pre-heat cycle....

 

 

[Nick D]

1 hour ago, Alan de Enfield said:

There is no correct answer.

 

Everything is a balance of cost of batteries vs life of batteries, vs amount of Ah used vs cost of running your engine to recharge them.

 

The general consensus is that not going below 50% SoC is probably the most economic option.

Do not let your batteries goes below 12.2 volts, and them charge them immediately to as a high a state of charge as you can then with 8+ hours running every few days to get them back to somewhere near 100% SoC

So before I had the BMV I was using an analogue voltmeter.  It was very difficult to judge whether the reading was 12v, 12.2v or even 11.8v.  If they were actually regularly going down to 12v could that be the reason they are now failing, notwithstanding that it seems that my regime is fully charging the next day?

Edited July 8, 2019 by Nick D

[Dr Bob]

19 minutes ago, Nick D said:

So before I had the BMV I was using an analogue voltmeter.  It was very difficult to judge whether the reading was 12v, 12.2v or even 11.8v.  If they were actually regularly going down to 12v could that be the reason they are now failing, notwithstanding that it seems that my regime is fully charging the next day?

But without a BMV, how were you checking they were full?

[Nick D]

Since I’ve had the BMV it appears that they are being fully charged by my cruising hours etc..  This pattern has always been the same before so I think it’s fairly safe to say they If they are being charged now, they were being charged then. Could be wrong tho!

[mrsmelly]

Just been thinking about this topic. To reiterate we have 4 110 ah sealed jobbies. Now two plus years old with fifty fifty plugged in/off grid. Moored up at 6pm yesterday had tv on and all usual stuff. The mains fridge and seperate mains freezer are never off. We have used leccy all morning with tv and pumps etc. I just nipped and looked at my monitor and with 0.3 amp being drawn by the combi by batteries are now sat at 12.6. No solar whatsoever. Even in this hot weather my mains fridge and freezer work very well and are not running often.

[Nick D]

This makes me pretty sure that my batteries must be on their way out. In that situation we’d be around 12.2 mark

[Dr Bob]

1 hour ago, Nick D said:

This makes me pretty sure that my batteries must be on their way out. In that situation we’d be around 12.2 mark

Yea, but Smelly said his were at 12.6 with a very light load. IF that was my system it says he would be at 90% SoC ish so has used only  45Ahr ish since yesterday evening. That seems a bit light. With TV's. fridges etc we use 100Ahr+ overnight. So on 440Ahrs capacity, you would be down to 12.4-12.5 ish.