And it does not take much of a generator to fix the problem.  Much cheaper than 
larger batts.  

From: Mathew Howard 
Sent: Thursday, August 8, 2019 9:18 AM
To: AnimalFarm Microwave Users Group 
Subject: Re: [AFMUG] LVD

The only real reason I can see for using an LVD, is if the voltage going to low 
is going to cause problems... for example, ePMP radios have a feature where 
they can be reset to defaults with a power cycle sequence - I have seen that 
get triggered by the voltage going to low (probably actually because the PoE 
device that was powering them started shutting down). I don't see it really 
mattering that much for saving batteries... if it's happening often enough that 
it's going to significantly damage the batteries, you obviously need a lot 
bigger batteries, or a generator.


On Thu, Aug 8, 2019 at 9:58 AM <[email protected]> wrote:

  My problem with LVDs over the years has been the hysterisis.  Power has been 
back on for an hour but the voltage is still not high enough for the LVD to 
power everything back up.  I never saw any difference in battery life in sites 
with LVD and non LVD.  Generators are the way to go.  

  From: Ken Hohhof 
  Sent: Thursday, August 8, 2019 8:22 AM
  To: 'AnimalFarm Microwave Users Group' 
  Subject: Re: [AFMUG] LVD

  Another approach if you can’t get out there fast enough with a portable 
generator would be strategic load shedding.  Often we see that 90% of the 
customers are also without power so we’re getting no benefit by keeping the APs 
running, but maybe we’d like to keep the backhauls up so other sites aren’t 
affected.



  My observation is once you get to the LVD trip point, the rate at which the 
battery voltage is dropping has accelerated and there’s not much runtime left 
anyway.  Also I worry about equipment getting into a locked up state if the DC 
voltage got too low but didn’t cleanly go off and back on.



  Normally we try to have enough battery runtime that we can get there with a 
generator.  There are extreme circumstances though, like widespread power 
outages, or we’ve had ice storms that took down power wires but also made the 
roads impassable for 24 hours.



  I do sometimes wish battery management systems with built in LVDs would let 
us adjust the trip point a little lower, like maybe 19 or 20 volts instead of 
21.





  From: AF <[email protected]> On Behalf Of Chuck McCown


  Sent: Thursday, August 8, 2019 8:57 AM
  To: AnimalFarm Microwave Users Group <[email protected]>
  Subject: Re: [AFMUG] LVD



  Philosophical question.  With infrequent outages I would prefer to keep 
people on line for as long as possible,  So no lvd or set it below where the 
equipment ceases to function.



  If you have protracted outages get a generator.  I don’t see a use for lvd 
equipment unless it is in a remote area and powering non critical gear.

  Sent from my iPhone


  On Aug 8, 2019, at 1:12 AM, [email protected] 
<[email protected]> wrote:

    At what point would you want to enable an LVD on a 12V and 24V system?

    -- 
    AF mailing list
    [email protected]
    http://af.afmug.com/mailman/listinfo/af_af.afmug.com


------------------------------------------------------------------------------
  -- 
  AF mailing list
  [email protected]
  http://af.afmug.com/mailman/listinfo/af_af.afmug.com

  -- 
  AF mailing list
  [email protected]
  http://af.afmug.com/mailman/listinfo/af_af.afmug.com



--------------------------------------------------------------------------------
-- 
AF mailing list
[email protected]
http://af.afmug.com/mailman/listinfo/af_af.afmug.com
-- 
AF mailing list
[email protected]
http://af.afmug.com/mailman/listinfo/af_af.afmug.com

Reply via email to