Electronics, Lighting, & Gadgets - wireless computer battery life

My bike sat in the garage for a couple of months and the battery for the wireless sending unit was dead this morning. It seems as if the battery dies every time the bike sits for awhile. It's one of those odd sized 9v batteries, that so many brands use. I just wonder if I'm the only one who has battery life issues with these units. I'm on my third brand of computer now but I've had the problem with all of them.

So the question is what is the expected battery life with these transmitters? and why does the battery seem to die when the bike is just setting?

I'm an EE but I just can't see why these batteries seem to die so quickly, they're alkiline batteries so they should have a decent shelf life, and with the short pulses they use, I'd expect at least a year from them but the best I get is 6 months, and less if the bike sets.

Just wonder what others get.

GL

What brand computer and model is it?

I had the same problem with the fork mount speed sensor on my new Sigma BC-2006. The battery would go down too far to be useful after only three or four weeks. I wrote to Sigma's North American office. They replaced the sensor no questions asked. I assumed the new sensor had no battery in it, but I never looked. Winter came and I did not ride the bike with the Sigma on it. Three months later I discovered the sensor had a battery in it and it was still functioning perfectly well! The new sensor made a big difference. My suggestion: if you are not out of warranty, contact the maker and see if they will offer to replace the sensor. That may or may not solve your problem.

What brand computer and model is it?

No clue, either a pyramid, nashbar or BC. I've swapped them around as they've broken, or I've tried to get more battery life. The one on now has no markings.

The batteries last a long time in my Cateye WL comps.

They typically go 10,000 miles, or 1.5-2.0 years, whichever occurs first. The transmitter only uses current when riding, the receiver goes into sleep mode after sitting idle for a few hours, and then uses next to nothing.

I check mine with a meter; the batteries start out at ~1.6v and continue to operate all the way down to ~0.75v. It will operate at this low voltage state in summer, but when it gets cold you need more battery.

I think it also depends on how long the battery has been in the unit. It it's been in stock a long time before you get it, it could be low and not last long once yo ustart using it.

That happened to my Sigma, and I replace the batteries on the sending and head unit and it's working great. We'll see how long it lasts.

I think it also depends on how long the battery has been in the unit. It it's been in stock a long time before you get it, it could be low and not last long once yo ustart using it.

That happened to my Sigma, and I replace the batteries on the sending and head unit and it's working great. We'll see how long it lasts.

That's why i use a meter; it eliminates guessing. You should get a cheap one.

Typically new 1.5v nominal batteries have initial voltage of 1.55-1.65v. The new lithium disposables start out at 1.8v, with about 60% mass of equivalent alkaline battery.

Even sitting around for a long time they'll hold above 1.5v, by design.

And surprisingly even below 1.0v continue to work in cateye wireless computers.

Many devices will not work below 1.2v. Some bike lights, for example.

The batteries last a long time in my Cateye WL comps.

They typically go 10,000 miles, or 1.5-2.0 years, whichever occurs first.


TIme to think about a switch to a cateye. The battery in mine is one of those 1/3 AA, 9 volts. The voltage actually doesn't change much at all, about a 1/2 volt down when it fails, I'm lucky to get 2000 miles on it.