| It is strongly recommended that you use a
12 volt, rechargable, deep-cycle, sealed lead acid battery!
These batteries are designed to supply the amount of current needed over a long period of time. Other
types of batteries such as automotive and some marine batteries provide high current for short periods of
time which may damage some electrical components and result in a void of the manufactures warranties.
If your pet uses the house for an average of 10 hours a day, and you would like to have enough storage
in the battery to last 3 days without having to being recharged, then you would require a battery with ...
10 hours/day x 60 watts x 3 days = 1800 watt-hours
then: 1800watt-hours/12volts = 150 amp-hours
Thus you would need a battery with a minimum rating of 150 amp-hours.
|First, you must determine the amount of time that your pet will use the pet house. Try to determine the amount of time
that your pet will actually be settled into the house. Overestimating this time is better than underestimating and will
guarantee that there is enough power stored in the battery in times of no available sunlight.
NOTE: This estimate does not take into consideration the amount of time that the unit will be off, once the thermostat is
satisfied, while the pet is within the house, approximately 10-20 min/hr depending on heat losses. This will reduce the
overall power consumption thus getting more time/power from your battery and allows for more battery charging time.
|* Most batteries have an efficiency associated with them of around 80-95% thus a battery
rated at 150 amp-hours will have a storage capacity of approxiamtely....
150 amp-hours x 0.90 = 135 amp hours
It is recommended that batteries only be discharge down to 20% of their total capacity to maintain their
charging capacity. This also reduces amp hrs. available.
in the example this would translate to 135 X 0.80 = 110 AH
|Batteries are usually listed based upon their amp-hour rating and time, with the standard being the 20
hour rate. This means that the battery will discharge down to approximately 10 volts over a 20 hour
period of use at a specific current draw. Deep cycle batteries are designed to last and your battery should
give you a minimum of 5-6 years of performance with minimum maintenence. Some batteries have been
known to last as long as 20+ years depending on the amount of discharge it has endured over the years.
|We will gladly help you to chose a battery based upon your needs. Most recommended are the deep cycle, sealed, lead
acid type. Then you can purchase the battery yourself or we can arrange for delivery at cost of battery plus shipping.
|Second, you have to decide on how many days of storage you will want to have in your battery. This depends on the
amount of sunlight available to charge your battery. If you live in a location that may not get sun for several days then you
would need a greater amount of storage capacity in your battery.
FYI- photovoltaic panels will produce electricity even on cloudy days when there is very little sun. All they need is light.
|The following is an example of how to calculate how long a battery will last based on the
power required for the Heated and Cooled Pet House.