Solar Controller High Voltage - UPDATE

[xeitosaphil]

Having contacted Morningstar over several of the issues raised in post http://www.ybw.com/forums/showthread.php?380051-Battery-Solar-controller-High-Voltage

And Tony's suggestion in post 11 relating to when the use of the Heat Sink on the Morning Star Prostar 15 Controller coming into play,

they gave this response to my question (5)

5) In what situation does the Heat sink come into play?

Answer
“ Charge is regulated by PWM charging, when in PWM mode the current switching components generated heat, the heat sink dissipates the heat generated from the switching components ”

With regards to overcharging voltage set points, We see this issue quite a bit this time of year. The PS controller automatically adjusts charge voltage based on ambient air temperature. colder temperatures result in higher battery charge voltage. If the temps have been rather low lately, the controller may be doing this by design.
All the figures in the manual are taken @ ambient Temp of 25C. and are applicable to all quoted settings.

Apparently as my ambient Temp was 13C, which is 12C less, there is an increase of Voltage of

12 x Temp Comp. Coefficiency +5mVdegrees C per Cell - ( I missed the per Cell bit in the Manual )

With regards to my question why they would set the High Voltage Disconnect so high @ 15.2V over and above the gassing level with all the possible issues it could cause?

They chose to ignore it!

 

[parbuckle]

So presumably if you raised the temperature around your batteries and controller they would be charged at lower voltage , perhaps you could test somehow . The other issue is wether the batteries are happy at over 15v for what could be a prolonged period.

 

[xeitosaphil]

Having contacted Morningstar over several of the issues raised in post http://www.ybw.com/forums/showthread.php?380051-Battery-Solar-controller-High-Voltage



With regards to my question why they would set the High Voltage Disconnect so high @ 15.2V over and above the gassing level with all the possible issues it could cause?

They chose to ignore it!

As A follow on from this, ( probably not worth starting a new post as I think it is still in subject), does anybody know how long it would take approx, in minutes or hours for a 12v lead acid battery being charged at over 14.4v to actually start producing gas?

Would it happen instantly in a matter of minutes, or would it take possibly a few hours?

It could be relative to how long the batteries are being overcharged by the controller,amount of gas produced and possible quantity of fluid loss.

 

[xeitosaphil]

So presumably if you raised the temperature around your batteries and controller they would be charged at lower voltage , perhaps you could test somehow . The other issue is wether the batteries are happy at over 15v for what could be a prolonged period.

Batteries are in a cockpit locker so no chance of raising the ambient Temp to find out but I assume by what they say it would?