From: Barry Lotz 

Subject: station battery maintaining


Hi All
I have got my station components to work on 12 vts DC thru the use of DC/DC=
 converters.My thought was that the DC/DC converters are more efficient tha=
n wall warts and a UPS and the battery would last longer on a power outage.=
  I would like to have the system  run on a battery with something to maint=
ain the battery health while under an approx 1 to 2  amp load. . The proble=
m is what to use to keep the battery charged but also healthy. I tried a 1.=
5 vt charger/maintainer which worked for ~ 2 years. I am not sure whether i=
t's the battery or the maintainer which is malfunctioning. I can go into wh=
at I have done recently . My question is would a possible scheme be to run =
a 6 amp charger on a wall timer work to cycle the battery and prevent sulfa=
tion?  Maybe shutting off the charger for say 8 hrs each day then put back =
on a 6 amp charge would work. Alternatively is there a product  I could use=
 to have battery maintain charge and capacity for a reasonably long period =
of time.

=20

Hi Barry,=20

    Just what is a 1.5 vt charger/maintainer, please ?

    You don't say what sort of battery you are using at the moment ??

    Charge the battery, put a suitable light bulb across it as a discharge =
load to give about 10 hrs operation, measure the current and time how long =
it takes the voltage to fall to 11 volts.
=20
    First, measure the maximum current consumption of the equipment that yo=
u want to use.

    Then decide what duty cycle you want. If it is intermittent, can you ar=
range to switch on the battery charger at the same time as the equipment ?

    Then decide what time lapses / power outage times you want to cover. Yo=
u can then calculate the required battery capacity and add on 50% to 100%.=
=20
    I can get a 12/13.2 V, 2.5A regulated power supply / charger for about =
$25. =20
    I can also buy 13.8 regulated supplies for use with mobile radios etc i=
n the 3A to 10A range.
    As you are currently using DC/DC converters DO CHECK the allowed INPUT =
VOLTAGE RANGES. Some converters are VERY FUSSY !=20

    Don't run the system so that you drain out battery power and then recha=
rge intermittently. This will reduce the battery life A LOT, unless it is o=
ne of the special battery types designed for this use - and they tend to be=
 expensive. Check batteries designed for use in caravans ?=20
    You do need to check the input current to your power supply when there =
is no output. If it is switched on 24/7, this can use a significant number =
of units.
=20
    Hope that this helps,

    Chris Chapman
        =20

=20
From: Barry Lotz <barry_=
lotz@.............>


Subje=
ct: station battery maintaining

















Hi All


I have got my station components to work on 12 vts DC thru the use of DC/DC=
 converters.My thought was that the DC/DC converters are more efficient tha=
n wall=20
warts and a UPS and the battery would last longer on a power outage.  =
I would like to have the system  run on a battery with something to ma=
intain the battery health while under an approx 1 to 2  amp load. . Th=
e problem is what to use to keep the battery charged but also healthy. I tr=
ied a 1.5 vt charger/maintainer which worked for ~ 2 years. I am not sure w=
hether it's the battery or the maintainer which is malfunctioning. I can go=
 into what I have done recently . My question is would a possible scheme be=
 to run a 6 amp charger on a wall timer work to cycle the battery and preve=
nt sulfation?  Maybe shutting off the charger for say 8 hrs each day t=
hen put back on a 6 amp charge would work. Alternatively is there a product=
  I could use to have battery maintain charge and capacity for a reaso=
nably long period of time.




 



Hi Barry, 



    Just what is a 1.5 vt charger/maintainer, please ?



    You don't say what sor=
t of battery you are using at the moment =
??



    Charge the battery, put a suitable light bulb across it as a =
discharge load to give about 10 hrs operation, measure the current and time=
 how long it takes the voltage to fall to 11 volts.

 

    First, measure the=
 maximum current consumption of the equipment that you wan=
t to use.



    Then decide what duty cycle you want. <=
font size=3D"2">If it is intermittent, can you arrange to switch on the battery charger at the same=
 time as the equipment ?



    Then decide what time lapses / power outage times you =
want to cover. You can then calculate the required battery=
 capacity and add on 50% to 100%. 

    I can get a 12/13.2 V, 2.5A regulated p=
ower supply / charger for about $25.  

 =
   I can also buy 13.8 regulated supplies f=
or use with mobile radios etc in the 3A to 10A range.<=
/font>

    As you are current=
ly using DC/DC converters DO CHECK the allowed INPUT VOLTAGE RANGES. Some converters are VERY FUSSY ! =




    Don't=
 run the system so that you drain out battery power and th=
en recharge intermittently. This will reduce the battery life A LOT, unless it is one of the special battery =
types designed for this use - and they tend to be expensiv=
e. Check batteries designed for use in caravans ? <=
/font>

    You do need to check the input current to your power supply when there is no output. If it is switched on 24/7, this can use a significant number of units.=


 

    Hope that this helps,



    Chris Chapman