Equalisation charge - is it a waste of time?

[tree monkey]

On 06/06/2019 at 20:50, cuthound said:

 

Yes, my first car was a Riley Elf. Walnut dashboard, leather seats and a bigger boot compared to the Mini.

 

In my opinion, the extra weight of the boot improved the already good handling of the Mini, but of course took its toll on performance.

Not saying much really is it, a min boot is smaller than a small thing left in a boil wash for too long. 

 

Saying that I did lose a can of beans under the spare wheel in a mini boot once, caused me no end of sleepless nights wondering what the noise was

[cuthound]

50 minutes ago, tree monkey said:

Not saying much really is it, a min boot is smaller than a small thing left in a boil wash for too long. 

 

Saying that I did lose a can of beans under the spare wheel in a mini boot once, caused me no end of sleepless nights wondering what the noise was

 

Well it did mean you could carry a squishy bag and a can of petrol, rather than having to choose ?

[Tom and Bex]

On 04/06/2019 at 12:16, Alan de Enfield said:

I think these 'modern calcium' batteries are more prone to a short life than the 'old' FLA batteries.

 

Discuss.

That's definitely our experience, although charging at a much higher voltage (15v) does seem to mitigate that to some degree. We only got just over a year out of our last set, hence the decision to go lithium.

 

On 04/06/2019 at 13:54, cuthound said:

 

Until we know the actual life expectancy (as opposed to predicted lifespan) of lithium ion batteries in a boating environment I would avoid those too, as they could also prove to be an expensive mistake.

There is plenty of real life experience of these batteries in sea going boats in the states, and experience points to life expectancy of 10yrs plus and 5000+ cycles in low charge and discharge usage. I agree they're not for everyone though and over charge or discharge will kill them quicker than lead acid!

 

On 03/06/2019 at 23:16, Richard10002 said:

What make and model of old style car charger was it? Were you able to set the voltage,Mir was it designed that way.

Not sure on make - just an old 10a car charger with transformer and no fancy controls! Voltage keeps rising slowly as current falls so ideal for equalization etc.

[blackrose]

I've bought a bench power supply and I want to do a monthly equalisation charge of 15.3v / 3.5a on my new bank of Trojan T1275s to keep them maintained. My charger doesn't have this facility.

 

If possible I'd like do the whole bank together rather than disconnecting everything. Is that ok?

 

Also do I need to disconnect the batteries from my battery charger (which only puts out 14.8v and not rated for higher voltages) and my semi-sine wave inverter to prevent any damage?

[Alan de Enfield]

1 hour ago, blackrose said:

Also do I need to disconnect the batteries from my battery charger (which only puts out 14.8v and not rated for higher voltages) and my semi-sine wave inverter to prevent any damage?

Not a recommendation, but, I have never disconnected anything and the charger and inverter still (for now) work.

[Momac]

The equalisation charge has done no good . I will be needing new batteries.

Currently pondering whether to repeat the last cheap order and expect 4 year battery life again.

[blackrose]

19 minutes ago, Alan de Enfield said:

Not a recommendation, but, I have never disconnected anything and the charger and inverter still (for now) work.

 

Thanks. It's only 0.5v above what they would normally be subjected to so I'm sure it will be ok.

[WotEver]

1 hour ago, MartynG said:

The equalisation charge has done no good . I will be needing new batteries.

Currently pondering whether to repeat the last cheap order and expect 4 year battery life again.

4 years is pretty good going.

[Dr Bob]

On 08/06/2019 at 10:28, Tom and Bex said:

That's definitely our experience, although charging at a much higher voltage (15v) does seem to mitigate that to some degree. We only got just over a year out of our last set, hence the decision to go lithium.

 

There is plenty of real life experience of these batteries in sea going boats in the states, and experience points to life expectancy of 10yrs plus and 5000+ cycles in low charge and discharge usage. I agree they're not for everyone though and over charge or discharge will kill them quicker than lead acid!

 

I hadnt seen this thread before

 

http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069.html

 

but it is interesting that the lumpy water boaters have been using LiFePo4s for quite a while. Beware, this thread has nearly as many pages as the Brexit thread...and it started in 2011 so 8 years experience. It is interesting that there are not many negative experiences of batteries failing...although I have only scanned 20% of the pages. The last 40 pages refer to the 'memory' effect and a number of threads have spawned off this linked one on charging and memory etc. Yea, life expectancy is 10 years plus. The mechanical issues do not seem to be the problem that I worried about in my previous posts.

[Momac]

23 minutes ago, WotEver said:

4 years is pretty good going.

I am reassured by that thought.

 

Higher quality batteries would be as much as  double the cost (or more) but I am not sure they would last longer in terms of £ per year .

 

[WotEver]

33 minutes ago, MartynG said:

I am reassured by that thought.

 

Higher quality batteries would be as much as  double the cost (or more) but I am not sure they would last longer in terms of £ per year .

They might, but are you likely to keep the boat long enough to appreciate the saving?

[Keeping Up]

On 04/06/2019 at 12:16, Alan de Enfield said:

I think these 'modern calcium' batteries are more prone to a short life than the 'old' FLA batteries.

 

Discuss.

Agreed. One reason is that the calcium inhibits gassing, hence promoting sulphation. Our previous set of batteries, Varta Hobby series, didn't start gassing until almost 16 volts which made it difficult to do an equalisation/desulphation charge - not only was it difficult to produce the requisite voltage (I eventually bought a cheap variable-voltage power supply unit) but also I had to be careful to disconnect them properly as many items of the boat electrical system are rated at a maximum of 15v or 15.5v.

[Momac]

57 minutes ago, WotEver said:

They might, but are you likely to keep the boat long enough to appreciate the saving?

Possibly. 

It's a nice (lumpy water) boat,ticks most of the boxes .

The next step up in size would need to be newer to suit the chief officer making the price of a  battery or two look like pocket change.

 

[Richard10002]

6 hours ago, blackrose said:

I've bought a bench power supply and I want to do a monthly equalisation charge of 15.3v / 3.5a on my new bank of Trojan T1275s to keep them maintained. My charger doesn't have this facility.

 

If possible I'd like do the whole bank together rather than disconnecting everything. Is that ok?

 

Also do I need to disconnect the batteries from my battery charger (which only puts out 14.8v and not rated for higher voltages) and my semi-sine wave inverter to prevent any damage?

I know they’re not the same, but I’m reasonably sure that 6v T105s have a 16.2v equalisation charge..(ETA)...for a 12v pair .. is 15.3v going to be enough?

Edited July 31, 2019 by Richard10002

[MtB]

13 minutes ago, Richard10002 said:

I know they’re not the same, but I’m reasonably sure that 6v T105s have a 16.2v equalisation charge.... is 15.3v going to be enough?

 

I think it's more likely to be 8.1V... 

 

[Richard10002]

54 minutes ago, Mike the Boilerman said:

 

I think it's more likely to be 8.1V... 

 

You are, of course, correct.

 

Edited to add "for a 12v pair".  

[blackrose]

My power supply instructions say that when using it for high demand the negative output should be connected to the ground post to reduce output voltage ripple.

 

Should I connect them to do an equalisation charge?

[WotEver]

I can’t think of any reason why not. Mind you, a bit of ripple isn’t going to affect the batteries anyway. 

[blackrose]

Why isn't it connected by the manufacturer if it's important?

[dmr]

I usually equalise at 15.5 volts and it works ok. When there was quite a bit of sulphation I have gone to 16 volts.

The 3.5 amps sounds a bit optimistic, what is the max current output of the bench power supply?

As the batteries age the tail current goes up. I have 6 T105s and never get a tail current below about 5 amps, usually more like 8.

I start to equalise when the tail current is less than about 20amps, I do it from the alternators and there is just not enough time to wait for a really low tail current..

 

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

[blackrose]

10 minutes ago, dmr said:

I usually equalise at 15.5 volts and it works ok. When there was quite a bit of sulphation I have gone to 16 volts.

The 3.5 amps sounds a bit optimistic, what is the max current output of the bench power supply?

 

5 amps.

 

But I'm on shore power with fully charged batteries. I'm only going to do an equalisation charge from that starting point. Is that feasible?

 

If I switch my charger off and back on the tail current is below 5 amps within a minute.

 

I was just going by what Alan said in his posts earlier about using 3.5amps.

Edited July 31, 2019 by blackrose

[dmr]

6 minutes ago, blackrose said:

 

5 amps.

 

But I'm on shore power with fully charged batteries. I'm only going to do an equalisation charge from that starting point. Is that feasible?

 

If I switch my charger off and back on the tail current is below 5 amps within a minute.

That will probably be ok, but you might hit problems as the batteries get older. How many have you got?

 

If you are on shore power long term and can charge at 14.8volts then I suspect you will hardly ever need to equalise.

 

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

[blackrose]

5 minutes ago, dmr said:

That will probably be ok, but you might hit problems as the batteries get older. How many have you got?

 

If you are on shore power long term and can charge at 14.8volts then I suspect you will hardly ever need to equalise.

 

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

 

3 x 150 amp hour. What sort of problems? It's when they get older that I will need equalisation/desulphation.

 

If the tail current of the batteries is 10amps will the 5amp bench power supply just not work? 

 

Should I have bought a bigger max output bench power supply?

Edited July 31, 2019 by blackrose

[Richard10002]

7 minutes ago, blackrose said:

 

3 x 150 amp hour. What sort of problems? It's when they get older that I will need equalisation/desulphation.

 

If the tail current of the batteries is 10amps will the 5amp bench power supply just not work? 

 

Should I have bought a bigger max output bench power supply?

The picture of Alans', (de Enfield), power supply, only seems to go up to 3.5A, and it's in the red from 3.0A. So I'd guess that your 5A will be fine.

Edited July 31, 2019 by Richard10002

[blackrose]

Just now, Richard10002 said:

The picture of Alans', (de Enfield), power supply only seems to go up to 3.5A, and it's in the red from 3.0A. So I'd guess that your 5A will be fine.

Ok thanks