Getting the La Crosse C86234 Working and Sending to Weather Underground

I saw the La Crosse weather kit at Costco for $80ish dollars and I had to get it. I have been looking at home weather stations for years. I believe that a Davis system that is wireless and has the interface so you can connect to a computer can be over $400.00. Now went ahead and got it, then looked at the reviews online. I know, sorta impulsive. After finding mixed reviews, I soldiered on.

Here are a couple reasons about why I continued with it. One, It is cheap. You should expect it to be cheap. It's housing, in my opinion, is pretty flimsy and if you drop any of it, it will likely break. I am sure after being in the weather for a year or two, it will be in trouble. However, a good Davis unit is many times more expensive. So I can throw this kit completely away every year for many years before getting to the cost of a Davis system. Another plus is it is completely wireless. That is both a benefit and a technical hurdle.

So, this thing is WIRELESS and is the typical 900MHz auto sync'er upper thingy that is designed to be easy, but can also be frustrating. One thing you have to consider: A LOT OF THINGS ARE IN THIS FREQUENCY SPACE. You and your neighbors have tons of wireless gadgets this thing may have to fight with. It is possible you won't be able to get it to work at your house. This is one reason you should buy this thing from someplace where you can return for refund without a hassle.

The instructions on setting up the unit, although brief, is complete enough to easily set it up. And the part about getting your weather units synced up and working should be followed as they print it. There is a good reason for this. You may assume, like I did, that the wind unit, the rain unit, and the temperature/humidity unit all transmit their readings to the base unit. That is NOT correct. The wind unit and the rain unit transmits its readings to the temperature/humidity unit. The temperature/humidity unit transmits its readings and the readings from the other two units to the base unit. So it is important to follow this order (as indicated in the instructions):
1. no batteries in anything
2. with the wind unit charged up (at least a couple hours in the Sun if 1st time install), press the reset button
3. put the batteries in the rain unit
4. put the batteries in the temperature/humidity unit
5. put the batteries in the base station.

Now you may find this wireless setup a bit odd. But actually, it is VERY NICE. See, there is 200 ft line of sight* range between the base station and the temperature unit. And there is 200 ft line of sight range from the temperature/humidity unit to the rain and wind units. That means your rain and wind units can be 400 ft from the base station. This greatly increases the flexibility of placing the units around your house. Since there is this 'relaying' of information between the units, you can do things like placing them on different sides of the house which would not be possible if they all went back to the base station.

*Remember that the ranges are line of sight. While 900Mhz stuff can penetrate walls and bounce around some, trying to get them to communicate like this greatly reduces the range. When placing the units, try to place them with none or as little obstructions as possible. For example, if you can see the temperature/humidity unit from the Wind unit, that is perfect. Speaking of ranges, there is a 60 ft line of sight limitation from the base station to a computer. It comes with its own transceiver and the communication is the same 900Mhz technology the rest of the kit is using.

Once they are synced up (and as long as you don't have interference issues), they should stay that way until you move the units around or have to change the batteries. Therefore you want to place these units where you can get to them easily. If you move any unit (including your computer), expect to have to repeat the resync process. Fortunately, the sync procedure between the computer and base station is independent of the weather stations so if you need to resync the computer, you won't likely have to resync your outside stations.

Now, these things are outside. The wind unit is powered by an internal battery that is charged by a solar panel. The rain, temperature/humidity, and the base station use batteries. They give you a nice set of alkaline batteries for the units. Keep in mind that alkaline batteries seriously loses power when gets really cold (all batteries do to some extent). I have elected to get some AA Lithium batteries (not rechargeable ion) and use shells to convert them to C batteries for the temperature/humidity unit (no need to worry about the indoor unit). AA Lithium is usually close to the capacity rating as alkaline C batteries at normal temperatures and do a much better job at freezing temperatures. If you are located in a very cold climate, no small battery may work for you. I wouldn't go as far as getting lithium batteries until you have everything working and are comfortable with the setup (no need to spend extra money on something you will throw away :) )

I recommend getting everything working to the base station first. And let it run for like a week or so. Make sure it is functioning and everything. Then move on to getting it working to the computer.

They provide a link to the software La Crosse produced for this unit called Heavy Weather. Make sure you get the right version for the unit you have. They also provided a USB stick that is your transceiver. You basically plug in the USB stick. Install the software. It either comes up trying to sync or you go to a pulldown to tell it to resync. I would go to the base station, hold the RAIN down button til it beeps, then go and tell the software to resync after you have installed the software and started it. If it is in range, it syncs up very quickly. Remember, you only have a 60ft line of site between the base station and the computer, so the computer can't be too far from the base station. That means you may be able to be one 1 room over if going through a wall (and that's a big maybe). This brings up another minus, if you are expecting to use Cumulus or another popular 3rd party weather software, it will likely not work. You should assume to stick with this software and I highly recommend using as computer running the Microsoft Windows Operating System since I have seen some complaints trying to use a Mac. I let this run for a few days to verify it is working correctly and it stays connected. Under Extras->Options, I also changed the update interval to 1 minute and selected to keep the communications to the base station in high speed mode.

I picked a old machine running Windows XP Pro to be my weather relaying PC. I did this because I checked online and I found out there is a product called WUHU which can upload data from various weather stations to Weather Underground, including this unit. You can get WUHU from http://home.comcast.net/~wuhu_software/ . It works well, however, I have read there has been issues with WUHU running with newer versions of Windows (and some issues with Heavy Weather as well). So I picked Windows XP to avoid any issues. The install was easy, I installed with default options and I started it. I told it to run as standalone for now (not uploading to Weather Underground) and went into the config to tell it to look at c:\Document and Settings\All Users\Application Data\currdat.lst by selecting the La Cross option in the pulldown that mentioned that file. After a minute or so, it populated the screen with readings from the base station. For sanity, I compared those readings to what Heavy Weather was saying to make sure there was no mistranslations (I didn't find any). I then logged into Weather Underground and registered the station. It wanted the address, longitude/latitude, elevation of the station. It gave me a 9 character station ID in return. I went into WUHU options, and under heavy weather, gave it that ID and a password (which is the same password as you use to login to your general account on Weather Underground). Went back to Weather Underground and under my stations, it showed it was active almost immediately.

I placed Heavy Weather in the Startup folder of the default user on my Computer so it will start on reboot. WUHU did this for me during it's install. I also configured the registry of the computer to login as the default user automatically. These things aren't running as services so a user needs to be logged in. There are security dangers and you risk making your computer not boot by changing the registry so I'll leave you to search for that if you choose to take those risks. I also changed the BIOS settings of my machine to turn on on power failure.

So far I have found the instruments themselves to be very accurate. I suspect the wind vane is a little hyper sensitive and the temperature sensor may be a little slow to react to temperature changes. But otherwise, I am very impressed for it being a very cheap unit. My readings seem to compare well to close-by units I find on Weather Underground.

That's about it. And here is my station:

Please comment if you have any questions!

UPDATE (10/25/2012): After a week or two I noticed that I had issues with the base station dropping from the Heavy Weather software. Not because it lost sync, the software was saying that the USB adapter wasn't there. I am guessing there is some sort of memory leak or other driver crash. If I reboot the system within a certain time frame of the event, the PC would not lose sync with the base station (not really sure why the base station loses sync if this event happens for too long before correcting). I added a scheduled task to reboot the PC once a day (doing a shutdown -r). It has been stable since.

19 Comments

LaCrosse weather station c86234

Did not find your very useful site until after I ran into problems. Wish I had, and that I coudl have read your helpful info' first!!
But would like to add my comments just in order to help others, because although I did search on line before I bought these stations I did not find this sort of useful info'.
And i should say that some of my problems are because I had two other people helping me and the second did not know what the first had done and I did not know that the first person had not understood the directions, and so the second helper was at a disadvantage. (the problems of being an elderly widow). Even so, the problems I encountered were PRE-Re-set anyway.

Paid $79.95 at costco. Was Soo excioted to find this - went home and read up on LaCrosse. It had good reviews. Made a special trip back across town to buy it. I am in the foothills of Albuquerque, NM.

My family spent 4 hours setting it up. THE BOX DID NOT INDICATE THE VERY SPECIFIC REQUIREMENTS FOR INSTALLATION!!!. (How many people have 6 foot above ground poles available to install anything on)??? I have a FLAT roof so had to get posts to mount the wind sensor and the other hygro something on - (it is 'sposed to be UNDER the eaves (problem - no eaves!), preferably on the north side of the house. No line of site from here. Whatever place you choose to install, all units have to be on the same side. So we got two posts and made small platforms for the units. installed them.
ALAS, the wind sensor does not work - and that was the thing i was most excited to get!!! It appears the other units are reading, fairly accurately.
HERE ARE THE REST OF THE PROBLEMS.
To re-set (which is required regardless of the number of non-functioning units) you are 'sposed to remove the batteries IN ALL UNITS and replace them within a certain amount of time. And apparently also in a particular order. Well, i am 5'3'' and the wind sensor is on a telephone pole at 6 feet, on a gravel slope. There is no way to put up a ladder against that telephone pole. NEXT PROBLEM: The Batteries in the rain sensor require that I take the unit apart by twisting the cover off firmly, and then, with a screw driver remove two long phillips head screws - from the top side - (the heads of the screws are reached from the top of the sensor. Well that sensor is at a disallowed 4'6" (so that I can do required CLEANING of it at intervals) but reaching the top side of this unit will also be impossible.
I have not tried any of these trouble shooting efforts as it is pretty much of a physical impossibility to reset any of these units, let alone ALL of them.
I had called Lacrosse for help. Waited two days. went back and found that LaCrosse tech help replies take 4 to 5 days for a reponse, unless you email them, which may take 2-3 days. ONLY there is NO email address that I could find. Still have not heard from them. It has been 5 days.
Actually I bought FOUR as major Christmas gifts - will have to take them back - it is such a disappointment and do you think my son is going to be happy to help me with any other projects ????? Not likely!! I feel so bad for putting them to all this trouble - and then to have to return the units - and then - I don't have neat gifts for christmas either!!!

LaCrosse c86234 wx stn

I received my LaCrosse as a Christmas gift - like lots of other folks.

I was excited to get the stn up and running. I thought I was following directions; over and over with negative results.

Finally, I gave up and returned the stn to Costco. No problem except this Costco was sold out. I rushed over to another Costco store and latched on to another unit.

This time, I followed the instructions to a "T." And guess what....? The set up took all of 12 minutes. LIttle things like "reset" with a 60 Watt (or better) bulb close to the unit. The order of step X step setup. Waiting in between steps.

I think the person/s who handled the documentation verbiage should have not relied on mundane text to get the vital procedure accross to the many readers.

rain guage help

I just found your site ..All of my station is working great except rain ..I charged the wind up all night 14 hours under 90 watt bulb ..Thermo hygro is under front porch wind is 25 feet up in middle of roof great readings had a 32 mph gust in winter storm ...Cant get rain to read anything but 0 ...Hate to do a complete restart any ideas my batteries are fine rain guage and display are within 2 feet of each other ..I want to give people my email gsmith862@juno.com ..Happy New Year !!!

works - sort of

I too found the unit at Costco and was thrilled to get the system for the price. What I did wrong in my first attempt to get the station going was not following the instructions to the letter. This resulted in the anemometer not working, I was bummed so I went back and started over, this time making sure all of the instruments were sitting together on the floor with the base station to start the sync process. Once I did this process all of the instruments started working!

I got the Heavy Weather software installed on my PC and got the station to sync with the software. At this point I thought everything was golden, only to return to the PC a few days later and discover that the unit was staying in sync with the PC. After reading your article I believe that the problems lies in me moving the base station too far away from the PC. So I'm going to resync and move the base station to the same room.

I had wanted to upload the data to Weather Unground like you have done and had all but given up hope of making that happen, but now I think I can make it work. Thanks for the post and here's to me getting my station publishing to WU.

Try rebooting too

Thanks for the reply! You reminded me I needed to update the web page. I found that USB adapter gets lost by the software after a certain amount of time. I am guessing it is some sort of memory leak or driver crash. If I reboot the PC and if it reboots quickly enough, the base station doesn't lose sync. But it will lose sync if it stays in that condition long enough. I added a scheduled task in Windows to reboot the machine once a day. It has stayed synced since. This may not be your issue, but it is something to try if you exhaust other options to try to keep it synced.

Good luck!

Weldon

Good Buy

Just read your nice review. I also came about this station while walking at costo, $79, great price, and so far so good. Couple of years back and also at costco I bought another La Crosse weather Station (WS 2316) its been working very well for the past 5 years.
Setting up the new station was both simple and easy. Its wireless capabilities not only make it simple to set but they actually work very well. Havent tried sending the info to my mobile phone ,,, yet!

LaCrosse C86234 Weather Station

Like many other I too purchased this unit from Costco. I thought for $79 bucks how could you go wrong. I followed the instruction carefully and found the Wind sensor did not work. I tried a number of attempts first re-trying the instruction up to and including a reset.

My big dissapointment was when I called LaCrosse tech support. I waited on hold for about 40 minutes just to be routed to a recorder to leave my message. I gave up waiting for a call back after 4 hours and called back again. I waited about 20 minutes and got to a technician. I explained the problem, he said the Wind sensor probably was not sufficiently charged and to wait 24 to 48 hours before trying again and call back if that didn't fix it.
Well, I waited 2 days before trying again, the wind sensor was under a 75 watt light bulb for at least 48 hours.
Attempt 2: Same problem, I called back to tech support, after waiting again and getting "leave your message" I decided to remove the bottom cover from the unit, a little probing with a volt meter and it looked like one of the rechargeable batteries did not register any voltage.
I removed the circuit board and bingo, the problem, one of the tabs that make contact with the battery wasn't making contact with the battery. I bent it back into place, re-assembled the sensor and bingo I was able to see the wind sensor. (This of course makes me wonder how many others have had this same problem)
I placed the different units (not physically attaching them) to where I intended them to be.
Every thing seemed to work but I was dissapointed with the refresh time, especially on the wind direction and speed.
After playing with the unit a little more I felt this lag time required for update was un-acceptable, boxed it up and back to Costco it went. Never got to play with the remote software
I imagine if it had worked without any issues I might have overlooked its shortcomings and the lousy tech support. I fully agree with Weldon this unit is cheaply made and probably won't last more than a few years outdoors, especially since I have seen how the wind sensor was constructed internally.
Bottom line, you get what you pay for! And after doing additional research I have found out the refresh rates on a Davis are under 2 seconds, much better than that of the LaCrosse.

In summary, the LaCrosse unit will provide reasonable bang for the buck if you don't have any issues, count on it crapping out within 2 years or less. If you want really accurate and up to the second information go with a Davis.

Same Problem as others here

Wow,
I having the exact same problem with my wind sensor also. I not about to dissassemble it. Mine has a label over the edge of the wind sensor that I would have had to remove to open the bottom up. I think you would probably void the warranty if you removed it.

I called tech support and got the same story as you. The funny thing is I can hear something rattling inside the wind sensor when I shake it. Somehow I don't think charging it is going to fix it.

I will try it again tomarrow and if it still doesn't work its back to Costco it goes. Obviously LaCrosse seems to have some quality control issues both in production and tech support.

I think I will have to agree with the statement "You get what you pay for"!

My experiences with the Lacrosse Tech C86234 from Costco

I'm 74 years old, an Ham Radio Operator (General) and have been involved in tech stuff all my life. I have never had as much trouble with a product as I did with this one. However, I got most of it whipped.
The instructions/procedures , I felt were very poorly worded and presented almost like they were an afterthought "Oh, we need some instructions". Most problems could be avoided by using better fonts, grammar and page design. LaCrosse should sure be able to do MUCH, MUCH, better.
The part that I am having difficulty with is the logging process. This also could be made a lot clearer with better examples and discussion. Damnably poor. Hopefully, I will be able to work through it.

Heavy Weather

Biggest issue people have with unit is heavy weather is that the station does disconnect from the USB. Most people also do not read the Heavy weather manual that is provided on the website. After reading the system requirements you find that you need to change your power management settings so you Tower if a desktop, or plug in settings if a laptop, needs to be committed or on all the time. If the USB has no power then the connection is lost. At times you can have a defective USB. The people at the call center were very helpful replacing my USB stick and I have never had an issue. For warning. They are not a large call center, max 25people and a call back depending on what the issue is could take a day or two. The lady that help me educated me well on the product and how the software works. For how much I payed for this unit I cannot complain. Plus someone is there help you even if you have to be patient.

Second most common issue is the wind sensor. 1st be sure the sensor is FULLY charged under a lamp for a full 24 hours. If you set the unit up already and it did not work you need to charge the wind sensor and try again. But its not just taking batteries out and put them back in. FIRST the wind sensor has a reset button but its more like an on and off switch. If you press it once its on if you press it again its off. Cover the solar panel when you press the reset button once and its off. Then take batteries out of the Rain and Thermo hygro sensor only. Leave batteries in the display. Power up the wind first by pressing the reset button once with the solar panel exposed then put batteries in the rain and thermo hygro sensor. Wait 2mins and press the hold the UP arrow button until display beeps. Let go and wait 5mins to see if data appears. If its still not working then you need to do a FACTORY RESET. This is on their website under the model number when searched in the FAQ's. Usually it fixes the problem. It worked for me. Otherwise call support. Even if you have to wait they can help you.

La Crosse C68234 and weewx - a plug for weewx

Like many others who have posted here, we got a La Crosse C68234 at a Cosco sale in December 2012. We immediately found the HeavyWeather software to be cumbersome and not very easy on the eyes. The requirement to keep a Windows computer running 24x7 just for the station was also less than desirable.

So we made the station work with weewx.

weewx is a open source python software that easily runs on plug computers. We run it on an Ionics Nimbus computer that consumes less than 5 Watts, so leaving it on 24x7 is no problem. Some people run weewx on their home router, so no additional computer is required. weewx collects data from the La Crosse station then generates web pages that can be viewed from any computer. Customizing the web pages is straightforward, and there are a few different 'skins' available, from static HTML to interactive graphs with historical data. weewx can also upload to Weather Underground, CWOP, PWSweather, WOW, Smart Energy Groups, COSM, Open Energy Monitor, or pretty much any other service you can imagine. Instead of using the alarms on the C86234, use weewx to notify you of weather changes or low batteries. For example, weewx can send an email when temperatures reach a certain level or the wind exceeds a certain value from a specific direction.

Like many open source projects, there is some learning curve to installing weewx. But unlike many open source projects, weewx includes extensive documentation, examples, and a friendly user's group.

http://www.weewx.com

LaCrosse weather station

So SAD

about the Costco weather system, mine does not work either ;-(

Do not buy a LaCrosse WX station from Costco or anyone else

I am a ham radio operator and also have a commercial radio telephone license and many years of experience working with communications electronics. I bought one of these units from COSTCO and despite repeatedly going through the listed initialization procedure I was unable to get the wind speed unit to communicate with the base unit. I reported this on-line and got an automated response and never got any followup. I then tried numerous times over several weeks to call their listed warranty/technical service number and despite staying on the line for in excess of thirty minutes each time no one ever answered their telephone. I then sent a letter to Lacrosse threatening to sue them for failure to provide warranty service and got ZERO response. This company obviously has a "no service, customer service" policy. Their equipment appears to be junk and they simply do not stand behind their alleged warranty. Do yourself a favor and please do not go through the aggravation I did by avoiding buying anything from this company.

c86234

I had a problem at first because I did not read the directions.
after placing the wind speed unit in full sun for 1/2 hour (no 60 watt bulb) and pushing reset button and then installing the other batteries as directed the unit works flawlessly in fact so well that that i ordered a second one on line for $59.00 and $2.00 shipping

Sometimes I'm too smart to read instructions

Like some on here who have posted about their frustrations setting up the Lacrosse c86234, I have an extensive background in technical expertise both in wireless and hard wired configuration and control. Quite often I find that the packaged instructions are more of a hindrance than a help and can usually set up and configure any device that has communications capabilities. I did however assume that since the box did not include any manuals that setup instructions would probably be even less useful. I was wrong. I had gone down a path that would not work no matter how I tried. I eventually sat down and did a little search and found this blog. The many different comments all pointed to me that there are some inherent problems with the units as a whole but that for the most part I should be able to get this working. I went back to square one and followed the instructions as painful as it was for me and voila! everything worked just as advertised. I am still trouble shooting the system though, it seems that the rain gauge stops communicating with the base. I can reinitialize everything and the communication is restored only to drop out again after an hour or so. The base displays the battery as being good for the rain gauge. I have checked this by installing weak batteries and getting the correct reading on the display on the Heavy weather screen. I am thinking there might be an issue with the rain gauge because everything else works very well. I look forward to new challenges the next hurdle will be trying to figure out how to hack the signal so I can capture it using other devices than just the base. Considering I didn't spend allot for this I wasn't expecting it to be a top of the line unit. So far it has performed above expectations. Thanks for the support.

Weather Station

I asked for and got my weather station for Christmas. It was purchased by my daughter from Costco for the same cost posted by others.
I skip around instructions. So I had plenty of setup issues. Others posting their installation wows sure rang a bell...LOL. The pole, etc.
Anyway when I finally read the instructions carefully and followed them, my Wind Sensor still wouldn't work. I suspected internal issues and by then we were months after Christmas. I'm a "know how it works, fix anything" kind of guy. So, I pulled it apart and sure enough there was an issues with the install of the batteries by the factor. Mainly the contacts did not have enough tension to get real power through the connection. So, I repaired the battery issue. After that everything did connect properly.
On to the installation.
I was able to get all my equipment installed, including the "repaired" Wind Sensor up on the roof using a board screwed to the edge of the roof and the flat screw mount attached to that. It all worked pretty well and reasonably accurate for about a year.
Then I moved and moved the unit over to my new home. It was some of the first stuff that I set up. It was placed on the edge of the roof using an fiberglass pole from a broken yard tool and using roof TV antenna mounts. This worked better and allowed me to add some height above the roof. Still not much higher because there wasn't a lot of fiberglass pole left of the broken tool. I DID NOT want to put a metal pole on my roof fearing a lightening strike.
Anyway that lasted about another year. But, actually started to fail during the cold weather. My Rain Sensor went out and shortly after that the Wind Sensor failed. Well, so far I have gotten probably several years or more of service. So maybe I should have counted myself as lucky and gotten a new one. But, I pulled the two units down and started to repair them. I found one of the two rechargable "alkaline" AAA batteries had failed. I tested it with regular batteries and it worked. So, I got some lithium rechargable AAAs and put them in. Then reassembled the unit. I don't recommend anyone should try to repair the wind sensor. It is a pretty tricky assembly and has a lot of tiny little parts that you might miss. It's hard to reassemble.
Despite any of my efforts, I can NOT figure out what has happened to the Rain Sensor.
I'm hoping maybe somebody has an idea what to look at or try. It appears to be on one of the boards. I know it isn't transmitting, so perhaps something on that part failed. It does look like I can buy a new one of those for @ $50 and ,maybe that's the way to go. But, like all of us know, I can probably replace my aging unit for about $80. So instead of buying one new sensor for more than half the complete set price, I think I might hang on for these to show up soon again at Costco for the holiday season. I have everything accept my rain sensor working. The repaired wind sensor is back on the roof. It on an even taller plastic conduit pole this time. It's about 6 feet about my very tall roof peak.
Any help would be great.

I love all the new information I found here. It was great read about everyone else's experience with the kit. I'm not shocked by many of the failures or returns. It takes a lot to get this working and properly installed. I also think the manufacturer got into a pickle when he went for producing more volume to supply Costco. I think that caused the original issue I had to repair on the Wind Sensor. It should have resulted in a return. I knew our Costco did not have any more of the units, So I couldn't exchange mine and I still wanted a weather station. BTW: I had pretty terrible technical support from the LaCrosse company when I called in. No doubt they were also overwhelmed by all the new users and kits.
I will be looking and hoping for these to arrive at Costco for the Holiday Season So I can replace mine.

If anyone knows how I can repair my Rain Gauge please reply.
Thanks,
Mark

Wind unit failure to transmit

I've had this La Crosse weather station for about 5 years, no complaints once I figured out the start up. Logging has been good over the 5 years with a new fie every year. Recently, the wind unit failed to transmit to the weather station - no particular reason to me. All other sensors transmit as they should just not the wind/direction unit. Tried resetting the unit, pulling and reinstalling the batteries on the temp unit. No go. Any suggestions?

not sure

For me, I lost line of site of where I had my wind unit by the growth of a tree. That is the main reason I had to stop using mine. The Wind unit on mine has permanently mounted batteries, I would expect after 5 years the batteries would go bad or the solar charging part of it would go bad.

Wind Unit Repair

Probably the rechargeable batteries in your wind unit have worn out. You can carefully disassemble the unit and replace the rechargeable AAA alkaline batteries with NiMH batteries. To disassemble the wind unit, first remove the plug from the top of the wind vane, then remove the screw under the plug and carefully pry the wind vane off of the shaft. Then remove the screws around the perimeter of the bottom of the unit. You can then remove the cover and you will find the two batteries. Replace them and reassemble.

There will be a loss of range with the new batteries due to the lower voltage of the NiMH (1.2V) instead of the 1.5V alkaline. Mine worked well after replacement but would lose connection when the temperature dropped below 0F. Good luck...