PowerTap SL 2.4 Wattage Issues

Triathlon Forum
1

All:
I’ve been training and racing with Saris’ PowerTap SL 2.4 for the past year and have had no issues. However, I just changed all the batteries-i.e. the battery in the head unit and the two #357s in the hub. I also updated the software from Saris’ site. I then went to program 5 and “relearned” the hub followed by the zero torque procedure. Started a moderate trainer ride and immediately noticed that the wattage numbers were all over the place, from 100 to 450. Crazy-no way can I push 380 watts for 20 minutes. I went back and repeated the above procedure to no avail. I also went back to Saris’ site and read everything. It seems that for some reason the head unit–or hub does not hold the zero torque?

2

couple of possibilities here.

  1. the hub or CPU batteries were not installed properly, i.e. bad contact.

  2. the hub batteries are not good quality ones that died on the spot.

  3. did you update the firmware for the right model of your PT? There is no wireless Pro that has been around “for the past year”

Is this the first time you’re replacing the hub batteries?

By the way i’m a bit confused by your post because the wireless Pro+ hubs have only been out for like a month or two at most. Prior to the 09 models, only the 2.4 SLs are wireless. So why was there a need to relearn the hub with a wired PT system?

3

My bad, I have the PowerTap SL 2.4, I’m losing my mind. I bought it last march. Yes, this is the first time I replaced the batteries in the hub.

4

well i would check the battery connections first.

If those are ok, then i would consider putting in a new set of silver oxide batts to see if it’s a battery issue.

FWIW, i’ve found that not all silver oxide batteries are created equal. I’ve had very good experiences with a brand called Renata.

5

Thank You Footwerz, I will try new batteries, where can I get that brand? I did notice that the hub had the silver oxide batteries when I took them out. I looked around, at CVS etc and finally found the 357 at Office Max. I will try to find the Ranata brand.

6

Any brand will work. The 357s are widely available as they are used in medical devices. You can also find 10 packs (or more) for sale on eBay that are very cheap.

7

Any brand will work. The 357s are widely available as they are used in medical devices. You can also find 10 packs (or more) for sale on eBay that are very cheap.