12v Zephyr Power Vent - connection and settings...

[alyaz]

I have a Zephyr Power Vent (12v model) that has never been installed.  It was left here by the previous owner.  I added a larger vent tube out of the battery box and figured it would be a good time to install the power vent.  I tested the power vent on a 12v battery and it works fine. 

Anyway, I got it set up on AUX 1 and used the ‘vent fan high’ setting.  Also changed the jumper settings to make 12v power at AUX 1.

So what voltage have you found that works best as a set point to have the fan come on?  The online info for Power Vent suggests 26.4v for a flooded 24v battery bank, but not sure if that’s best or not...  Is it just a matter of watching and smelling and tweaking the voltage that suits me best?


Thanks... 

[Vic]

Hi Al,

Glad that you did get the fan set up on Aux 1,  and it works.

From the "Specs"  there appears to be no maximum current specified by the manufacturer,  just a not that the 12 V model needs less than 3 watts (IIRC) ...   this would be about 250 mA from 12.00 volts,  a bit of an overload on the Classic's Aux 1 output ...  if you have an issue with the fan not running under certain conditions,  or the Classic resetting on rare occasions,  you might try adding a small resistance with the 12 V output of the Aux 1 terminals,  connecting to the fan,  to limit the current to just under 200 mA max ...

Would normally expect one to want the fan to start somewhat below Gassing voltage for your batteries.   Depending upon the SG of your batteries,  etc,  they might be expected to have a Gassing voltage of about 28,  or so volts.  So perhaps one volt below this,  might be fine.

As an aside,  your Vfloat seems quite high to me. EDIT:  perhaps you Edited out your Vabs and Vflt (??),  do not see it now ...   perhaps it was dreamed!)<<   Is this the recommended Float voltage from the manufacturer?   Perhaps they (Davidson)  may have guidance on either Gassing voltage,  or vent fan voltage.   When the batteries are warm/hot,  one would expect the fan voltage might want to be reduced ... and so on.

I have no experience with these fans,  as we use a bit of natural convection to clear the Power Room.

Just my opinions,   Good Luck,   Vic

[alyaz]

Hi Vic

Yes I edited out the battery parameters thinking they would not be much use to anyone.

Davidson recommends the following set points:

Absorb: 29.7
Float: 28.2
EQ: 31.8

I agree, the float does seem high, compared to other battery manufacturers and the default set points I have seen.

Regards,
Al

[kitestrings]

I have no experience with these fans,  as we use a bit of natural convection to clear the Power Room.

We've approached this a little differently.  I like the fact that it keeps the gases separate from terminals and other metals in range to be affected.



Al, I'd use the fan too if I were in your situation.  ~ks

[Vic]

Hi Vic   ...

Davidson recommends the following set points:

Absorb: 29.7
Float: 28.2
EQ: 31.8

I agree, the float does seem high, compared to other battery manufacturers and the default set points I have seen.
Regards,  Al

Thanks Al  for reminding me of the recommended charge parameters from Davidson.

What is your target SG  for a fully-charged battery,  out of curiosity?

Seems to me that that Float voltage would be at,  or very near Gassing voltage for most Lead-Antimony batteries,  with SGs of about 1.265,  wondered if the fill SG of the electrolyte is fairly high on your batteries.

Thanks,   Vic

[alyaz]

Specific Gravity

The specific gravity of your Davidson battery is somewhat different from other brands of battery. They are actually fully charged at a lower specific gravity than most batteries and as a result they will actually be charged before most hydrometers will indicate full charge. The most accurate way to use a hydrometer to measure state of charge is to take note of when the specific gravity stops rising. Take readings every 1/2 hour during the last part of Absorption Stage, when the hydrometer does not rise from your last reading the batteries are fully charged.

The correct fully charged specific gravity of your Davidson battery is:
1.265 - 1.275 ( this will vary dependent on battery age, condition and ambient temperature)

[Vic]

Hi Al,

Thanks for the info ...  would have guessed from the charge parameters that the target would have been somewhat over 1.280  if it were a Lead-Antinomy battery ...   shows what I know.

Should have asked this before,  what is the charge voltage Temperature Compensation coefficient?

Thanks,   Vic

[alyaz]

Hi Vic

I have no idea!  I called Davidson and they didn’t know either but are checking.  ha!

Anyway asked them what voltage they would set a fan to come on / when gassing occurs and they said 28v.  So, you were right...again!

We had a nice sunny day here today.  So I tweaked the fan to come on at 27.8v and waited around as the voltage crept up.  There was no smell of gassing or indication of gassing before the fan came on so it seems all good for now. 

Thanks.