nigelmercier
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I asked about this and was told it was because otherwise the batteries may not reach full charge in the available time. But I agree it is not ideal.
SEC AGM Batteries
- Thread starter Leonidas
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I asked about this and was told it was because otherwise the batteries may not reach full charge in the available time. But I agree it is not ideal.
Leonidas
Well-Known Member
Answer
Lifeline AGMs do not come cheap, thus if I could get them up to spec again it will be more than a welcome situation.
One of the problems I have is that AGMs are not widely known in Greece ( where the boat is) and I do not believe that the diagnostic instruments or methods used by the local electricians are appropriate for this type of battery. The batteries are also quite heavy, so it is not an easy task to offload them and send them to a battery shop for equalization.
Thus, Will it be possible to buy a dedicated "equalizing unit" which I can use onboard?
Thank you for taking the time to help out on this.
nigelmercier
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- Live in Kent, boat in Canary Islands
I got my Lifelines delivered to Greece, as we were passing through. All arranged by their sales department in the USA.
Leonidas
Well-Known Member
If I were to follow Sterling's recommendations for their charger ( which I have) they state that one should not use higher than the recommended (by Sterling) settings and also that one should always use the lower values if battery information is not available. Never the higher.
Though quite a clear statement, it becomes rather confusing in my situation, as I do have the option to use the same settings as that appropriate for the wet battery . This setting will boost up the voltage to 14.7 v. So the question here is, if I were to use this setting, would it be sufficient for the equalizing process ???
Leonidas
Well-Known Member
I had them shipped there through Barden's
Plevier
Well-Known Member
Mr Sterling is well known to have some rather individual ideas especially about AGM batteries.
I would always say go by what the battery company says, particularly where you have such excellent detailed instructions as you have from Lifeline. Concorde who make them is a pretty well reputed specialist company although small. (We got our aircraft AGM batteries approved in the US before they did though
)Is 14.7V the highest you can go?
You've nothing to lose by trying it!
npf1
Well-Known Member
The one I've used is a Xantrex, similar to this but an older model: http://www.sailsmarine.com/ItemDetail.aspx?c=39334&l=g&cc=GB
I think CTek do them too, although IIRC, not as many options as the Xantrex one.
I think CTek do them too, although IIRC, not as many options as the Xantrex one.
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Leonidas
Well-Known Member
Thank you for pointing me to this direction, but is this charger's capacity sufficient for a 2 x210 Ah + 1 x105Ah bank of batteries?
Looking at Lifeline's site, they are marketing the CTek as their chargers
npf1
Well-Known Member
IIRC the equalise charge is at a high voltage but at a low current, so I would have thought - but stand to be corrected - that the battery bank sizing of a charger relates to the bulk and absorption stages of charge rather than the float or equalising.
But if lifelines are selling CTEK, it sounds like you have your answer as CTEK are widely available over here. Also, you could equalise your batteries separately, if it's not too much hassle to disconnect them one at a time.
But if lifelines are selling CTEK, it sounds like you have your answer as CTEK are widely available over here. Also, you could equalise your batteries separately, if it's not too much hassle to disconnect them one at a time.
Plevier
Well-Known Member
Yes that's the normal case - waiting to see if sailinglegend can give a figure.
sailinglegend420
Well-Known Member
We now equalize twice a year when the capacity seems down. This will happen if we can't regularly (every 2-3 weeks) get the batteries back to 100%.
If you don't do that, as most cruisers can’t, then equalization is the next best thing.
You must fully charge the batteries first before applying the equalizing voltage so then the equalizing current is only a few amps.
This is a complex subject so see here for a long article on equalizing AGMs: http://www.morganscloud.com/2010/10/05/equalizing-batteries-the-reality/
Some extra thoughts:
The life of batteries is dramatically shortened by not getting them back to 100% charge - and that doesn't mean getting them back to 14.4 volts - or even to the point that the charger switches to FLOAT. Even in float they may still only be 90-95% of fully charged. They may have to stay in float mode for many many hours to get to 100%, so those with solar arrays who say their batteries are fully charged by midday are fooling themselves. Try forcing the charger back into absorption mode and watch the charger current go up from 0 to 10 amps and you will see they are not fully charged. Full charge is 0.5% of battery capacity at absorption voltage of about 14.2 volts.
Undercharging is why batteries need equalizing - once a month if you can be bothered - but it will make a big difference to their life.
So buy an extra charger with equalization and then run the two together for normal charging.
With AGMs you may have to change the charger settings back to wet lead acid otherwise the equalization mode won't work.
If you don't do that, as most cruisers can’t, then equalization is the next best thing.
You must fully charge the batteries first before applying the equalizing voltage so then the equalizing current is only a few amps.
This is a complex subject so see here for a long article on equalizing AGMs: http://www.morganscloud.com/2010/10/05/equalizing-batteries-the-reality/
Some extra thoughts:
The life of batteries is dramatically shortened by not getting them back to 100% charge - and that doesn't mean getting them back to 14.4 volts - or even to the point that the charger switches to FLOAT. Even in float they may still only be 90-95% of fully charged. They may have to stay in float mode for many many hours to get to 100%, so those with solar arrays who say their batteries are fully charged by midday are fooling themselves. Try forcing the charger back into absorption mode and watch the charger current go up from 0 to 10 amps and you will see they are not fully charged. Full charge is 0.5% of battery capacity at absorption voltage of about 14.2 volts.
Undercharging is why batteries need equalizing - once a month if you can be bothered - but it will make a big difference to their life.
So buy an extra charger with equalization and then run the two together for normal charging.
With AGMs you may have to change the charger settings back to wet lead acid otherwise the equalization mode won't work.
Plevier
Well-Known Member
You are spot on with all of that. Lifeline could add it to their manual for yachts!
You need 12 hours or more at 13.8 to get that last bit of charge in and it gets worse if not done immediately.
The only question is whether you can equalise so often without losing too much water over the life of the battery. There are design reasons why AGMs have little to spare. I think this is a case of the lesser of two evils.
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Leonidas
Well-Known Member
Thank you very much for this useful and practical insight. I think that I now understand the underlying problems. I can monitor the Voltage output of the charger at the battery end, but you are also refering to the amperage values. Do the chargers (with equalizing facility) come with amp meters? The Ctek ( Lifeline's recommended charger) only comes with led displays.
sailinglegend420
Well-Known Member
An amp meter would be no use because no charger or regulator can actually measure the current going into the batteries - that is the whole problem. The boat may be taking current to run other systems. That's why you must have a digital amp meter or a battery monitor to know what is happening at all times. The batteries will take whatever current they need during the constant voltage equalizing stage.
You may be able to tell chargers what type of battery they are being asked to charge but they don't know what size or state of charge the bank is. So they have to have different algorithms to try and determine when they think the batteries are charged. For example Victron stores the time it takes to get to the absorption voltage and then stay there for four times that value before it switches to float. So one hour to reach 14.4 volts will mean another 4 hours at that absorption voltage before it drops down to float of between 13.2 - 13.8 volts. They have to stop charging at absorption voltage to prevent gassing when the batteries are full - the problem is they will all switch to float early to avoid damaging your expensive batteries - which will happen if they are sealed and the water lost through gassing can't be replaced.
That is why deep cycle batteries must have multi-stage regulators on ALL charging sources on a boat.
Odyssey batteries now say that unless you have multi-stage regulators that can drop down to at least 13.8 volts then your warranty will be invalid.
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Leonidas
Well-Known Member
Thanks again for the advice. I think the way forward in my case will be to add an extra charger with conditioning facility as suggested. I do however have a couple more questions.
1.- Would an additional charger be able to work in tandem with another charger which have different charging procedures and end values ??
In the case of my existing Sterling Pro digital 40A, it is specified as follows:
Charging voltages:
Open Lead Acid: 14.8 V
Sealed Lead Acid and AGM: 14.4 V
Gel: 14.1V
Step charging:
Srep1: Maximum Current and Voltage: (14.1 - 14.8V) dependong on batterry type
Step 2: Absorption (Adjustable period during which voltage is kept to Max and current decreases)
Step3: Float, where voltage is kept at 13.6V
Step 4. Reset, if battery voltage drops below 11.5V in which case Srep1 cuts in.
There is no equalizing step in the programme.
However, these values are not outside Lifeline's ranges, and this is what I can measure with a multimeter at the batteries terminals. So I guess, the charger does what is written on the tin.
2.- I do have voltage and amperage instruments on the switch board so I can read the consumption and with all consumers to off positionI have a Zero amp indication. So apart from the suspected under charging, is there another area I should be looking at??
Plevier
Well-Known Member
Just had a look at the instructions for this charger. It does say "(The AGM and gel
voltages tend to vary from company to company so check which voltage your batteries require)"
Unfortunately it looks as though everything is preset and you can't get above 14.8V. However it looks easy to change from one battery setting to another. While you're thinking about what to do longer term, if you're going to the boat in the near future, why not set it to open lead acid 14.8V and run a full charge cycle or two? It's below Lifeline's recommended equalisation voltage but it might well make a difference as compared to 14.4V. It certainly won't do any harm. I wonder if it's worth asking Sterling if there is any way of inducing a higher voltage cycle?
Coming back to your previous reply about useage, can you elaborate a bit please. During your 2-3 months use are you living on board and during that period how often do the batteries get a mains recharge? Are you mostly on shore power or mostly out of marinas?
I'm still trying to remove any doubts that your problem is down to undercharging rather than being worn out.
When you are not there and the solar panel is on, is the solar panel output voltage regulated and at what level?
Plevier
Well-Known Member
I know what you mean but may I remove any possible confusion there - you mean not more than 13.8V (and I think they say not less than 13.5V).
Have you used Odysseys, how do you compare them with Lifeline?
sailinglegend420
Well-Known Member
I think the warranty says float must be 13.5 - 13.8 volts.
Not used Odysseys, but Nigel Calder seems to be having problems with the capacity holding up on his TPPLs for his all-electric boat. Merlin/Powerstore swear by them for starter/bowthruster work and it took three weeks to break one when they were testing them. They still recommend Lifelines as best for Deep Cycle only work.
Leonidas
Well-Known Member
Answer.
The Solar panel has its own regulator which is a sealed unit showing the stage of charge of the battery Red: 25%, Amber 25-50% Green 75% +
One can measure the charging voltage at the terminals (Panel to regulator and Regulator to battery)
Plevier
Well-Known Member
Quote Leonidas
I wonder if it's worth asking Sterling if there is any way of inducing a higher voltage cycle?
Answer
Sterling's view were quite emphatic that AGMs are waste of money, do not approve of them and are totally useless.Their only advantage is that they can be transported without any restrictions and thus can be sold my mail order. End of discussion, according to the guy who took the call!
His recommendation is to throw the AGMs away as they are finished, and use 6Volt arrays same as those used in golf carts. He said if I like I could go ahead and use the wet battery settings, ( i.e 14.8V) but it will most certainly gas up and dry the batteries in no time. In his view the batteries are dead and beyond redemption.
end quote
Well I did say before that Mr S has rather individual views
I'm afraid he judges all AGMs by the nasty ones that predominate, and he thinks he knows better than all the battery manufacturers about charging voltages. He is out of date on AGMs. All you can do is ignore him when he is in that mode! (AGM is not always the right answer though.)
It sounds as though you can't get above 14.8 which is a pity but I still say give it a go. 0.4V may not sound much but it is significant. I won't comment in detail about chargers - not my field.
Thank you for the other information. It really doesn't sound as though excessive cycling is the problem.
I wonder if it's worth asking Sterling if there is any way of inducing a higher voltage cycle?
Answer
Sterling's view were quite emphatic that AGMs are waste of money, do not approve of them and are totally useless.Their only advantage is that they can be transported without any restrictions and thus can be sold my mail order. End of discussion, according to the guy who took the call!
His recommendation is to throw the AGMs away as they are finished, and use 6Volt arrays same as those used in golf carts. He said if I like I could go ahead and use the wet battery settings, ( i.e 14.8V) but it will most certainly gas up and dry the batteries in no time. In his view the batteries are dead and beyond redemption.
end quote
Well I did say before that Mr S has rather individual views
I'm afraid he judges all AGMs by the nasty ones that predominate, and he thinks he knows better than all the battery manufacturers about charging voltages. He is out of date on AGMs. All you can do is ignore him when he is in that mode! (AGM is not always the right answer though.)
It sounds as though you can't get above 14.8 which is a pity but I still say give it a go. 0.4V may not sound much but it is significant. I won't comment in detail about chargers - not my field.
Thank you for the other information. It really doesn't sound as though excessive cycling is the problem.