Need to match new batteries with old panels

BB. said:

Here is one (I think it is the right one--no other options):

RTS - Outback Power Remote Temperature Sensor

-Bill

YES,  Bill that is the correct RTS for the OB FM CCs,   and well worth the price!

Dmitri,  it is quite possible that a major issue with your Trojan Flooded batteries was that there appears to have been no RTS on the FM-80.

During an extended EQ, the battery temperature can rise significantly.   This temperature rise requires that the EQ voltage be reduced ...  a further temperature rise requires yet further reduction in the EQ voltage,  and so on.   Without the RTS,  this required automatic voltage reduction does not occur.   Without this compensation,  battery current and temperature rise can increase above values that the batteries can tolerate,  and can approach Thermal Runaway.   This may well be the main factor in the issues with the Flooded batteries you have seen.

Sealed batteries,  like AGMs are more sensitive to proper charge voltages and Absorb time,  and they need a reasonable amount of time in Float,  to attain proper full charge.

AND,  with AGM batteries it is often  difficult to determine if they are being fully charged,  as one cannot measure the SG of the cells.  So,  in time,  these batteries can deteriorate from chronic undercharging.  On the flip side,  overcharging AGMs is also not good for them,  if this is done over an extended time period.

Also,  AGMs are more expensive,  and have about half the number of discharge  cycles,  compared to Flooded batteries.

What is the nature of "fried" condition of the present battery bank ...  did the plates become exposed to air from low electrolyte levels,  or ... ??

Please carefully consider your choice for replacement batteries.

Thanks for any additional details,    Vic

petertearai said:

Not sure if the fm 80 adjusts the voltage via the temp compensation during eqilisation . It is my understanding it will shut down eq  if battery temp reaches 50 deg  C . 

Hi peter,

Yea,  I DO know that the MX-60 definitely did NOT compensate Veq,  but have never run any FM CCs,  had hoped that OB would have added that important function.

The MidNite CCs DO allow the user to select weather or not the Veq is compensated -- have been using Classics for five years,  or so.   Compensation of Veq is important on longer EQs,  and for Automatic EQs,  otherwise,  for one or two hour EQs  the user can manually compensate at the beginning,  and perhaps again at the mid-point.

Thanks for that info,  peter,     Vic