Mastervolt IVO Smart 12/25-2 Charger

[Keevo52]

G,day all

The time has come to replace my nackered wet cell batteries with AGM,s my question is does the smart charger recognise what type of battery it is charging (Wet or Matt)or do I have change the chargers settings manually?, I have no manual or instructions for the charger which came standard on the Winnie when new(2002) I have found out that the Bulk Charge is 14.40v the absorption 14.25v and the Float 13.25, are these setting OK for a AGM? I have tried to get information from the Mastervolt site with no luck ( or I don't know what I am looking at)
any help appreciated
Cheers
Chris

[Craig]

hi Chris,

I have had a bit of a play with the 12/15-2 some time ago and yes you have to remove a Jumper on the back for charging AGM's. here is a link for that manual.

http://images.mastervolt.nl/files/Manua ... 213ALL.pdf

I had a quick look at the mastervolt site and couldn't see the 12/25-2 manual (they do list 12/25-3) but google it and have a look for your manual.

Edit: http://midsummerenergy.co.uk/pdfs/maste ... asheet.pdf

[Keevo52]

Thanks Craig, as I could not find any info on the net I sent an email to mastertvolt in Holland, at first I got the same manual that you directed me to, I resent the email with a few more known details and got a reply in an hour from the tech manager in Holland, he attached the correct manual which shows that I have to remove a link which is located on the side of the charger, this sets the correct float voltage, so all,s good, thanks for the input.( very good and quick service from Mastervolt)
Cheers Chris

[T1 Terry]

14.4v max and 14.25v absorption would be fine for AGM batteries, the 13.25v float would be ok for long term storage but useless for an operating system so it would require a shut down/reboot every day to get it back into boost mode if you were lving off the batteries. With the link remove, what is the new float voltage?

T1 Terry

[Keevo52]

G,day Terry
From the Mastervolt manual the float would be 13.8V after the link/bridge is removed, I do have a Ctek7000 charger topping up the crank batteries when needed, which when thinking about it I could have put onto the new AGM,s, in the manual for that charger they have a normal float setting 14.4V which is for wet, maintenance free, and for most gel batteries, another setting Mode, 14.7V float that is recommended for most AGM batteries, which do you think would be the best option? I can easily swap the chargers around to have the optimum set up with what I have.
Cheers
Chris

[T1 Terry]

I'd stay with the 14.4v boost and 13.8v float would be the better option as it's a mains charge not a solar regulator, so the charging can carry on 24/7. If the float voltage is too high it will continue to heat the battery and cause an early failure

T1 Terry

[Keevo52]

the plot thickens somewhat, I do have two solar panels of unknown voltage/output going through a plasmatronics controller, which cannot be adjusted as far as I know, I have no real knowledge of this set up as it was fitted to the M/H when we bought it ten years ago, I do have an DC amp meter which shows a maximum of 6 amps when the panels are clean but is usually around 5 amps or below depending on the weather, back to the mastervolt charger it does have a temperature sensor which is attached to the side of the battery, I guess this would tell the charger that the batteries are getting hot because of the amount of charge going into them, then adjust the charge accordingly, with this further info do I stick with your 14.4 boost and 13.8 float?
I appreciate your help with this as it is a bit of a dark art for me
Cheers
Chris

[T1 Terry]

I'd stick with the 14.4v and 13.8v float as AGM batteries generate heat when the recombine the oxygen and hydrogen separated by the electrolytic action involved in charging lead acid batteries. If too much heat is generated the electrolyte also starts to boil and the steam pressure causes the cases to bulge and distort, this buckles the plates leading to an early cell failure.
AGM batteries are a lot more sensitive to over charging than the old flooded cells were as they have a lot less electrolyte and the lost water is not easily replaced.
As far as the Plasmatronics controller, if it's a PL20 they are very adjustable and can be fine tuned to suit your use pattern better than most solar controllers on the market.

T1 Terry

[Keevo52]

The Plasmatronics controller has a series of led,s on the front face which tells you what is happening, Float, Boost, Load On and Charging, I have not taken it off to check out the rear of the unit where I guess there my be means to adjust the settings, so I will go with the 14.4v and the 13.8 float set up on the mastervolt charger, just a question, what is the real difference between the float charge going into the AGM,s 14.8v over 14.7 which is the lesser of the two, wouldn't the lower float of 14.7 produce lower temps to the batteries hence lesser chance of boiling the electrolyte?
again this is a murky black art to me
Chris

[T1 Terry]

The 14.7v boost for flooded cells compared to 14.4v boost for AGM batteries is all to do with heat generated. The flooded cell can have the water topped up, the AGM isn't designed that way. AGM batteries charge more efficiently than flood batteries, but flooded batteries can be equalise charged where AGM batteries can't so it's a bit of the round abouts and swings thing, none of them hold a candle to lithium batteries and never will as the technology is so old it's past it's use by date, but as they are cheap enough it's just a matter of living with the weaknesses.
If the Plasmatronics controller you have is only an LED type I doubt it has many variables that can be fine tuned, I was more refering to the PL20 and Dingo models.

T1 Terry