Instruction: Output yes if the supporting document can answer the given question. Otherwise, output no.

Input:
Question: battery
Document: Then it stopped working completely and the screen went blank.It has triangle screws in the back that are tamper proof, so there is no good way to look at or change the battery.
I had a manual timer and it would never keep the right time and would make loud noise when turning on and of. NOT THIS ONE. This timer is easy to program, battery back up is nice, read out is easy to read and clear. NO NOISE.
It handles the light on my fish tank at home. Its nice to have two programs ones for weekdays and one for weekends (where I can look at my tank more).Once you learn out to set it, its a breeze to add more events to. The battery int he unit is nice as its never lost setting do to power failures (which happen a lot here in Honolulu).
I bought two of these for my weekend home. I switched from mechanical timers mostly for the battery backup. There are lots of programming options (e.g. MWTuThF, SaSu, etc). Programming is pretty easy to do especially because I can unplug it and program it while standing up rather than having to lay on the floor. I only program a few on-offs 'cause it is kinda tedious.
I bought 2 of these on sale at a brick and mortar store. I noticed one had a blank screen, but thought the battery was dead and would recharge when I plugged it in... it did not, and never worked.The other one worked pretty well for over 2 years, although I would notice it was not turning on and off and need to reset it occasionally, maybe every 4-6 months.
The cleverest thing about this timer is that there is a little pocket/slot to store the instructions in. Most timers are notoriously hard to program - especially when you loose the instructions. This timer is pretty easy to program if you have the instructions. Whoever designed this should get an award for adding a slot to store the instructions in.Anyway - my cell phone battery was constantly being damaged from overcharging when I forgot to unplug it, so I bought this timer to limit the charge time.
Easy to operate right out of the package. The battery backup feature keeps the timer &#34;on time&#34; even with power failures. If you travel in the summer during thunder storm season, power outages are common and they throw off your cunning plan of having a timer turn on and turn off lights to make bad guys think you are at home. These new digital, battery back up, timers are so so so much better than those mechanical rotary models of yesteryear.
Tired of motorized timers, I got this digital model to control a floor lamp to come on workdays only. I was not disapinted. This is a solid performer and is easy to set up. In fact, I challenged myself to program it without reading the instructions, and was successful. I like this model because it uses only one outlet, leaving the top one free for non-timed loads, and it has a built-in backup battery to keep the time and programming through power outages.
I bought this digital timer 6 months ago to replace a 7 year-old mechanical timer and this is an excellent digital timer. The major differences between this digital timer and the mechanical timer are:1. It has a battery backup to keep accurate time in case of power loss.2. This timer offers (20) twenty precise on/off settings per day which far exceeds my requirements. You can even configure it for any day or group of days of the week.3.
what i need to turn off my dehydrator,  so i don't have to watch times.
Answer: yes