Advice Morning star 25a sun saver duo high charging voltage

[M0nsi]

Hi

I have a morning star duo regulator 25a with lcd display charging my battery bank on our motorhome, when the battery's are nearly fully charged the display is showing 15v dc the company have changed the regulator 3 times and still I have 15v when battery's are fully charged, it doesn't stay at 15v all the time however I don't know how long it stays at this voltage, when fully charged and not drawing any power from the van the float charge is 13.84 well around there.

The supplier told me to adjust the dip switches and I tried all the different setting from gel to wet etc, when set to gel batteries the voltage whent to 14.87v.
The display has a min & max reading for voltage so I can see the the voltage has reached high and shut the fridge down again.

The biggest problem is when the house voltage reaches 15v the fridge shuts off as it detects high voltage and it always does this when we're out for the day.
I am concerned that the 15v will damage the batteries as I have just fitted 4 new batteries

The solar set up on the motorhome as below

Sun saver 25amp duo by morning star
2 x 80w mono panels
1 x 120w poly panel
Roof mounted
Cable run is 6m long

Cable spec run from the roof is 25msq welders cable to the regulator fitted at the side of the battery bank
Batteries are 4 x varta hobby 90amp lesuire

Has anybody experienced anything like this or can any advise

Thanks in advance Brian

[Mike90250]

The morningstar charge profile may indeed go up to nearly 15V in part of the cycle. Their manual has a "profile" of what the charge protocol is, have you been able to read it ?

Don't rely on a "house" meter, use a quality DVM to get reliable measurements to base your sytem on.

[M0nsi]

Hi mike and thanks for the swig reply
I have use a good. Lie point multimeter for the reading and it shows 15, I have a NASA B1 battery monitor and reads the same voltage.
No paper work for the regulator so to sure.
Mike will it damage the battery's at that voltage?

[Mike90250]

....
Mike will it damage the battery's at that voltage?

Maybe.

FIRST, start with telling us what brand/model of the batteries are and what are the recommended charging specs for them.

SECOND here http://www.morningstarcorp.com/en/sun-saver-duo is the mfg's site for the charge controller, and it has a link (under downloads) for the manual. Download and read the manual.
Equalization Voltage =14.8 volts and you generally, DON'T want to equalize batteries more than a couple times a year, and NEVER if they are GEL or AGM.
Page 9 has the dip switch settings

I have the manual, now you can have it too. When someone says they have 15V at the batteries, I have no idea how wires are connected, what state the charger is in, if the shore power charger is running, if the vehicle alternator is charging.... Your local dealer should be able to help you some too. There are steps in the Morningstar manual for troubleshooting.
So after I've looked at the manual, I agree, 15V is too high, and you have to troubleshoot to find out what is generating the voltage. How low does the battery go at night ? Can you test the voltage of another vehicle battery before starting _______v After starting and while engine is running _____v That will give a sanity check for the accuracy of your meter.

[M0nsi]

Hi Mike

I have down loaded the pdf data sheet and on reading it they mention the the regulator has an inbuilt temperature sensor and this has a voltage skew +or-depending on the temperature.
The temperature in side the Motor home was-2 today, when a put my hand on the probe after a few minutes the voltage dropped to 14.5 at equalization, having read more you can over ride this by fitting a 10K resistor to the external temperature sensor connections.
Toady I fitted a 10K resistor and bingo it now works a treat.

Thanks for all the information and pointing me in the right direction

[Sunking]

The temperature in side the Motor home was-2 today, when a put my hand on the probe after a few minutes the voltage dropped to 14.5 at equalization, having read more you can over ride this by fitting a 10K resistor to the external temperature sensor connections.

Why are you on EQ? What type of battery do you have? Manufacture and model number please.

You can simply disable the temperature function, but should be used.

[M0nsi]

Why are you on EQ? What type of battery do you have? Manufacture and model number please.

You can simply disable the temperature function, but should be used.

The make of the batteries and the amp were in my fist post..
The model No is LFD90.
That was the only way I could disable the temperature sensor as I dont have the Computer interface.
The regulator was at EQ at the the time of checking.

[Sunking]

OK those are AGM batteries and they should NEVER be placed on EQ, and not to exceed 14.8 volts.

[M0nsi]

OK those are AGM batteries and they should NEVER be placed on EQ, and not to exceed 14.8 volts.

The batteries are not AGM batteries the are maintenance free lead acid wet batteries, I question was how to stop the regulator over charing, however I have now solved the proble.

http://www.tayna.co.uk/Varta-Hobby-Leisure-Batteries-S285-1.html

[Sunking]

We are talking about Varta Professional DC line up right LFD series correct?

[M0nsi]

We are talking about Varta Professional DC line up right LFD series correct?

These are the battery's which are fitted and they are not classed as a AGM battery, varta however do sell a AGM battery at a much higher price tag.

I can only tell you what is says on the paper work and on these battery's are not classed as AGM.

Look here. http://www.barden-ukshop.com/varta-p...ery-2273-p.asp

[Bala]

Sunking are you using that small mobile screen again,

OP said Hobby in his first post and the link a few posts ago says hobby!