16.8V charger for equalising Trojans?

[Richard10002]

3 minutes ago, smileypete said:

How many Trojans? Can you say, isolate and eq half of them while leaving the other half connected?

That would open things up to cheaper and more effective options.

4 x Trojan T105. I guess I could isolate 2 of them, but it would be a PIA.

Having said that, what would be a more effective option, (the £200 +/- cost of the Victron ip22 Smart Charger is fine in terms of the cost of a solution).

[WotEver]

3 minutes ago, Sea Dog said:

Ah.  I thought the gassing separated the Lead Sulphate coating from the plates.

The gassing is actually counter-productive. The more gas bubbles, the less the electrolyte is actually in contact with the plates. Gassing is an ‘unwanted’ but inevitable by-product of the high voltage required for desulphation. 

[nicknorman]

Just picking up on the original post, Sterling seems very remiss in not having a setting on the Combi which disallows the inverter to kick in if shore power fails. Mastervolt and Victron have a “charger only” setting.

[Sea Dog]

3 minutes ago, WotEver said:

The gassing is actually counter-productive. The more gas bubbles, the less the electrolyte is actually in contact with the plates. Gassing is an ‘unwanted’ but inevitable by-product of the high voltage required for desulphation. 

Appreciate that.  Explains the reasoning behind a max 1 hour equalisation charge which terminates early when the voltage is reached.  Somehow I'd picked up there was a bit of crud shedding usefulness in small doses too. 

[Richard10002]

5 minutes ago, nicknorman said:

Just picking up on the original post, Sterling seems very remiss in not having a setting on the Combi which disallows the inverter to kick in if shore power fails. Mastervolt and Victron have a “charger only” setting.

I asked Sterling about it shortly after I bought. His response was expectedly terse, along the lines of next years model being modified in this way - “tough”

[cuthound]

5 minutes ago, Sea Dog said:

Appreciate that.  Explains the reasoning behind a max 1 hour equalisation charge which terminates early when the voltage is reached.  Somehow I'd picked up there was a bit of crud shedding usefulness in small doses too. 

That is why several short equalisations, stopping after just 2 or 3 minutes, often helps with very heavily sulphated batteries.

[Dr Bob]

49 minutes ago, Richard10002 said:

Agreed, but not everyone has a 175A alternator. Mine reaches a max of about 30A... which is fine for a good charge on a day trip, but not so good when idling at the mooring.

 

Ours was like that, a 90A 2002 vintage. I bought a Sterling AtoB and everything is fine now. Lots of voltage, lots of amps.

When we are out and about our Amps in is usually down to less than 30A within an hour of start up although we tend to keep our batteries 'fullish' ie 660Ahr bank and use say 100Ahr overnight. That's why I think a 30A charger will be fine for when we arrive back on shore power, and like you said you can always switch back to the combi if you do need more ooomph.

[Dr Bob]

42 minutes ago, Sea Dog said:

Appreciate that.  Explains the reasoning behind a max 1 hour equalisation charge which terminates early when the voltage is reached.  Somehow I'd picked up there was a bit of crud shedding usefulness in small doses too. 

Can anyone explain the 'crud shreading'. I have seen references to the plates sheading material which weakens them and damages them. I understand the basic chemistry of the batteries but what chemical reactions are taking place in the shreading or is it simply a physical breakdown. Also a daft question - to what extent does equalisation extend the lifetime of a battery? Obviously it gets rid of the sulphate crystals which restores the 'active sites' on the plates so increases capacity back towards the original, but does it weaken the plate structure to the point where lifetime is reduced? Anyone who is equalising hasnt followed the 'rules' so the battery is not fully healthy but does equalising bring it back to fully healthy or is it just a temporary respite with the reduced 'strength' of the plates just as much a problem as heavy sulphation?

I am not sure how you will answer this question but I would be convinced if someone can say they have Trojans that are 10 years old and are regularly equalised.

[smileypete]

1 hour ago, Richard10002 said:

4 x Trojan T105. I guess I could isolate 2 of them, but it would be a PIA.

Having said that, what would be a more effective option, (the £200 +/- cost of the Victron ip22 Smart Charger is fine in terms of the cost of a solution).

I guess the PIA would be adding another isolator and moving everything to the non battery side of the isolators.

Maybe try the more conventional route and measure how much it improves things.

Reading in between the lines, seems you'd prefer an off the shelf type solution, then go for new batts if the improvement is too marginal.

Having a split bank would allow lots of short periods of eq to be applied automatically for greater gains, but it really needs to be done in summertime with plenty of solar, and it's by no means 'off the shelf'

Edited December 23, 2017 by smileypete

[smileypete]

23 hours ago, dmr said:

15.5v should be adequate for equalising Trojans unless you have let them get really badly sulphated, and a whole lot easier. Most electrical stuff on the boat will be ok with 15.5 volts but at 16.8 I am not so sure.

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

I expect that during EQ - and to a similar extent at end of a normal winter time charge - you want the Trojans to bubble nicely.

The voltage needed is going to depend on temperature and to some extent battery condition.

[smileypete]

15 hours ago, OldGoat said:

Isn't the whole problem of battery charging/ management / et al all part of the fact that 'most' users are using the wrong type of batteries?

Folks start with simple requirements - then graduate to requiring many of the demands of a land based life - but are unwilling / unable to upgrade their power source to an appropriate type of storage device. Reading through some of the threads where folks specify  their needs, it's clear to me that they need a resilient power source. At the upper end that cannot be satisfied by anything less that full traction batteries. Slightly lower down the expense / resilience  scale are semi traction batteries, but they need some care in management. That's a complete pain for newcomers who want (and why not) a fit and forget regime.

It ain't going to happen.

There's no middle course. Fiddle with the equipment, monitor every day top up regularly, replace the batteries at frequent intervals - it works. However, do people really want to do that?

OR spend a lot more and get it right from the start?

Would have thought decent leisures (eg Varta, Banner, maybe Numax) would be resilient enough for most use and largely fit and forget for part time use where the boat returns to a shoreline supplied mooring, though the cycle life is bound to be lower than tractions or the golf cart type batts.

I came up with three main scenarios on another topic, which I'd consider to be largely tue to life:

"Somewhere in another topic I suggested three main scenarios for batt ownership:

    Plan A for most (95%?) of boaters would be decent brand leisure batts.

    Plan B would be Trojans but only if they can be provided with the correct charge and EQ voltages, and required maintenance and monitoring. I expect this needs a genuine long term interest, hmmm...

    Plan C is to use a less common battery make/type/chemistry/desulphators etc, but then you may be the guinea pig on that one.

I guess most second home type boats fall into Plan A, and most off grid liveaboards move towards Plan B at some point."

What the above tends to assume is that the electrical needs of the boater are pretty average, I s'pse those in Plan A with very high expectations or needs will hit a steep learning curve sooner or later.

Edited December 23, 2017 by smileypete

[dmr]

31 minutes ago, smileypete said:

Would have thought decent leisures (eg Varta, Banner, maybe Numax) would be resilient enough for most use and largely fit and forget for part time use where the boat returns to a shoreline supplied mooring, though the cycle life is bound to be lower than tractions or the golf cart type batts.

I came up with three main scenarios on another topic, which I'd consider to be largely tue to life:

"Somewhere in another topic I suggested three main scenarios for batt ownership:

    Plan A for most (95%?) of boaters would be decent brand leisure batts.

    Plan B would be Trojans but only if they can be provided with the correct charge and EQ voltages, and required maintenance and monitoring. I expect this needs a genuine long term interest, hmmm...

    Plan C is to use a less common battery make/type/chemistry/desulphators etc, but then you may be the guinea pig on that one.

I guess most second home type boats fall into Plan A, and most off grid liveaboards move towards Plan B at some point."

 

I would add a D, a set of proper 2v tractions, though you could say this is really B++. However I have a slight concern about the lack of redundancy for liveaboards with a single bank of 2v tractions.

Plan E (which you could maybe say is part of your C) is a set of Lithiums. These look really good, especially for the better charging characteristic, but are just too expensive at present.

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

 

[WotEver]

4 hours ago, Dr Bob said:

Can anyone explain the 'crud shreading'. I have seen references to the plates sheading material which weakens them and damages them. I understand the basic chemistry of the batteries but what chemical reactions are taking place in the shreading or is it simply a physical breakdown. Also a daft question - to what extent does equalisation extend the lifetime of a battery? Obviously it gets rid of the sulphate crystals which restores the 'active sites' on the plates so increases capacity back towards the original, but does it weaken the plate structure to the point where lifetime is reduced? Anyone who is equalising hasnt followed the 'rules' so the battery is not fully healthy but does equalising bring it back to fully healthy or is it just a temporary respite with the reduced 'strength' of the plates just as much a problem as heavy sulphation?

I am not sure how you will answer this question but I would be convinced if someone can say they have Trojans that are 10 years old and are regularly equalised.

Gentle discharging and gentle charging will maximise battery life. Heavy charging and discharging physically damages the plates (they twist and bend), Plus the lead paste softens, all of which causes the paste to fall off (shedding). The better built the battery the more they can resist this. Equalising is just a higher-voltage charge so causes damage as above but it’s less harmful than having the plates covered in hard lead sulphate. 

Removing sulphate is permanent (unless you repeat the poor charging that caused it in the first place of course!). 

As with all things battery related, it’s a compromise. 

Obviously the above is with reference to lead acid Batteries. 

Edit to add: I should have pointed out above that shedding is more properly known as ‘plate corrosion’ but it amounts to the same thing. 

Edited December 23, 2017 by WotEver

[Sea Dog]

6 hours ago, WotEver said:

The gassing is actually counter-productive. The more gas bubbles, the less the electrolyte is actually in contact with the plates. Gassing is an ‘unwanted’ but inevitable by-product of the high voltage required for desulphation. 

 

5 hours ago, smileypete said:

I expect that during EQ - and to a similar extent at end of a normal winter time charge - you want the Trojans to bubble nicely.

Not the easiest subject this, is it!

[smileypete]

1 hour ago, Sea Dog said:

Not the easiest subject this, is it!

'4. Can I reduce my maintenance by not gassing my flooded batteries?
You will reduce the frequency of watering, but will cause a condition known as stratification where the specific gravity of the electrolyte is light at the top of the battery and heavy at the bottom. This condition results in poor performance and reduced battery life.'

http://www.trojanbattery.com/tech-support/faq/

I really do hate to say this, but I'd take some of WotEver says with a pinch of salt, it seems to come from the Gibbo school of 'misleading expertise'.

There's plenty of good information at the websites of The Battery FAQ, Trojan Battery and U.S. Battery.

[nicknorman]

5 minutes ago, smileypete said:

'4. Can I reduce my maintenance by not gassing my flooded batteries?
You will reduce the frequency of watering, but will cause a condition known as stratification where the specific gravity of the electrolyte is light at the top of the battery and heavy at the bottom. This condition results in poor performance and reduced battery life.'

http://www.trojanbattery.com/tech-support/faq/

I really do hate to say this, but I'd take some of WotEver says with a pinch of salt, it seems to come from the Gibbo school of 'misleading expertise'.

There's plenty of good information at the websites of The Battery FAQ, Trojan Battery and U.S. Battery.

 I think stratification is a bit of a myth for something like a boat with vibration, motion, and daily charges. Stratification is an issue with immediate bike batteries that are left for very little no periods on float.

All charging creates some gassing, it is just a question of how much. A bit of gassing is probably a good thing. Certainly for Trojans. A lot of gassing is no better and can cause a little bit of long term damage. Which is why batteries are best kept on float voltage not on absorb voltage. But in the battle between sulphation and plate erosion, it is just a matter of compromise.

 

[smileypete]

21 minutes ago, nicknorman said:

 I think stratification is a bit of a myth for something like a boat with vibration, motion, and daily charges. Stratification is an issue with immediate bike batteries that are left for very little no periods on float.

All charging creates some gassing, it is just a question of how much. A bit of gassing is probably a good thing. Certainly for Trojans. A lot of gassing is no better and can cause a little bit of long term damage. Which is why batteries are best kept on float voltage not on absorb voltage. But in the battle between sulphation and plate erosion, it is just a matter of compromise.

A narrowboat is essentially a stationary application with negligible acceleration,  braking and cornering forces.

Even car starting batts with very shallow cycles and vastly more movement can suffer stratification:

https://www.google.co.uk/search?q=car+battery+stratification

https://www.google.co.uk/search?q=site%3Ajgdarden.com+stratification

I think it may help to explain why leisure batts developed for the motor home market can fail quite badly on narrowboats.

Edited December 23, 2017 by smileypete

[WotEver]

3 hours ago, Sea Dog said:

Not the easiest subject this, is it!

But you quote two extremes

Pete said ‘at the end of a normal charge’ in which he is correct. 

I was talking more generally during the charge in which I am correct. 

As I said, it’s all about compromises.

Pete thinks he knows a lot because he’s read a website

That’s the same website that stayes that the losses noted by Peukert are in part due to the battery’s internal resistance. 

Edited December 23, 2017 by WotEver

[nicknorman]

12 minutes ago, WotEver said:

Pete thinks he knows a lot because he’s read a website

That’s the same website that stayes that the losses noted by Peukert are in part due to the battery’s internal resistance. 

It’s cleary a rubbish website then!

[WotEver]

5 minutes ago, nicknorman said:

It’s cleary a rubbish website then!

Yup, but Pete loves to quote it. 

[cuthound]

2 hours ago, smileypete said:

A narrowboat is essentially a stationary application with negligible acceleration,  braking and cornering forces.

Even car starting batts with very shallow cycles and vastly more movement can suffer stratification:

https://www.google.co.uk/search?q=car+battery+stratification

https://www.google.co.uk/search?q=site%3Ajgdarden.com+stratification

I think it may help to explain why leisure batts developed for the motor home market can fail quite badly on narrowboats.

If you put a glass of water on the swim, where the batteries usually are, you will see ripples in it, caused by the running engine. This tends to mix the electrolyte.

However, if the engine is rarely run,  and the boat spends a lot of time on a landline with the charger in float mode, then stratification is possible.

Edited December 23, 2017 by cuthound
To add the last sentance

[Dr Bob]

2 hours ago, WotEver said:

That’s the same website that stayes that the losses noted by Peukert are in part due to the battery’s internal resistance. 

...are the losses noted by Peukert are in part due to the battery’s internal resistance?

 

 

 

 

 

No, No, No, .....only joking!

Edited December 23, 2017 by Dr Bob

[Keeping Up]

The technical support people at Varta advised me to remove the batteries from the boat once a month and "shake them about a bit" to avoid stratification. Not the most useful advice really.

[cuthound]

30 minutes ago, Dr Bob said:

...are the losses noted by Peukert are in part due to the battery’s internal resistance?

I thought they were due to the ecofan effect? 

[WotEver]

29 minutes ago, Keeping Up said:

The technical support people at Varta advised me to remove the batteries from the boat once a month and "shake them about a bit" to avoid stratification. Not the most useful advice really.

Were they going to loan you a large strong man to assist?