Question for SRM PC 8 users.

Discuss light weight issues concerning road bikes & parts.
ichobi
Posts: 925
Joined: Thu Jan 19, 2012 11:30 pm

by ichobi

Hey, I have a few questions for PC8 users. I just received my unit from a friend and I am having a massive headache with it.

1. Can the PC8 unit be completely turned off instead of going on stand by? Sometimes I don't ride for a long time and the battery just go dead because I can't turn it off. Meaning I have to consciously keep it charged the night before the ride everytime. ...Instead of let's say just turning it off to save battery like every other unit in the market allows you to.

2. This is related to (1). and I don't know if I am dumb or have set it up wrong.. everytime the battery dies, the date and time will be stuck at the moment the unit was turned off. Meaning if I recharge it and turn it back on again, I have to set the date and time manually every friggin single time. I see you can set the time zone but that doesn't seem to set the date and time for the system. It does not seem to be able to sync time with the GPS either. If I did not set i up wrong, this feels like a piece of ancient technology. This is not an automatic watch and it annoys the hell out of me.

I can't find both answers in the manual either.

BdaGhisallo
Posts: 2279
Joined: Wed Mar 17, 2004 1:38 pm

by BdaGhisallo

The PC8 will always display a 'sleep' screen when it is not activated. There is no way to turn this off other than draining the battery.

Don't know about the time status. My battery never gets drained (I leave it plugged on the charger plugged into my desktop pc when not in use).

The GPS reception on the PC8 sucks in my experience. I have had two of them and neither one can find and lock on to a satellite signal as quickly or reliably as my wife's cheap running watch. In fact, on the few occasions I have tried I have waited five minutes for it to try and find a lock before giving up. But, I don't want or need GPS so I am not really bothered by this.

The PC8 is a really good head unit for monitoring power and the associated metrics. If you want GPS you will want to look at another unit.

by Weenie


ichobi
Posts: 925
Joined: Thu Jan 19, 2012 11:30 pm

by ichobi

I dont really use the gps function per say I am just annoyed about having to manually set up the time after the battery died. So you avoid this buy having it charged 24/7 then?


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BdaGhisallo
Posts: 2279
Joined: Wed Mar 17, 2004 1:38 pm

by BdaGhisallo

ichobi wrote: ↑
Sat Feb 09, 2019 10:40 pm
I dont really use the gps function per say I am just annoyed about having to manually set up the time after the battery died. So you avoid this buy having it charged 24/7 then?


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Yes, that’s right. My PC8 rarely gets below 80%.

johnrho
Posts: 37
Joined: Tue Jan 17, 2017 4:27 pm

by johnrho

ichobi wrote:I dont really use the gps function per say I am just annoyed about having to manually set up the time after the battery died. So you avoid this buy having it charged 24/7 then?


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My PC8 takes a week to drop from 100% to 80%, roughly a month to get down to 20%-40% when just in sleep mode. Even after rides every other day I don’t notice a huge battery drain. Not sure how long you go between rides or leave it in sleep mode but you may want to get the battery serviced by SRM.


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ichobi
Posts: 925
Joined: Thu Jan 19, 2012 11:30 pm

by ichobi

N i think my battery might have a problem. I drop like 30-40% after an hour ride. If I leave it in sleep mode it drops to zero in 3-4 days.


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ghisallo2003
Posts: 649
Joined: Mon Jan 02, 2006 7:10 pm

by ghisallo2003

I would think yes, you do have battery problem.

Although you need to set time manually, the time resets when it picks up GPS.

johnrho
Posts: 37
Joined: Tue Jan 17, 2017 4:27 pm

by johnrho

Have you applied all the firmware updates? I seem to recall that earlier releases of the PC8 had some issues with the battery and was discussed on a thread here


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Seedster
Posts: 545
Joined: Fri Jun 05, 2015 11:05 pm

by Seedster

My battery lasts a few weeks without charging in sleep mode. Sounds like you may have a problem with the battery or the unit is hunting for the GPS and killing the battery. I recommend what others have said to upgrade the firmware to the most current and then call for service if you see the same behavior.


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BdaGhisallo
Posts: 2279
Joined: Wed Mar 17, 2004 1:38 pm

by BdaGhisallo

Seedster wrote: ↑
Sun Feb 10, 2019 2:13 pm
My battery lasts a few weeks without charging in sleep mode. Sounds like you may have a problem with the battery or the unit is hunting for the GPS and killing the battery. I recommend what others have said to upgrade the firmware to the most current and then call for service if you see the same behavior.


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I would second this. If you do have the GPS enabled, turn it off and see how that affects your battery life. If it is still bad then you likely have a hardware problem.

johnrho
Posts: 37
Joined: Tue Jan 17, 2017 4:27 pm

by johnrho

Just to put it into context, I live in a condo and my PC8 never locks into GPS while it’s in my unit. So the theory it’s hunting for GPS signal as the cause of the battery drain might be a stretch.


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ParisCarbon
Posts: 1395
Joined: Mon Feb 05, 2007 5:39 am
Location: Winnipeg Canada

by ParisCarbon

Mine will go about a month of no use before it dies... I don't use it during winter months, maybe once a month on the trainer, and only to compare Neo vs SRM Watts for accuracy... as someone mentioned above, I also GPS issues...
The last 2 times Ive been in French Alpes staying in Freny d'Oisans I could literally stand on the curb for 5+ minutes before anything would happen.. I lost coverage on the Glandon... GPS satellite is line of sight, but still...
In Maui it seemed to take FOREVER to get a lock, meanwhile my friends Garmin would lock on immediately.. even on the front driveway its an issue some days..

BdaGhisallo
Posts: 2279
Joined: Wed Mar 17, 2004 1:38 pm

by BdaGhisallo

ParisCarbon wrote: ↑
Sun Feb 10, 2019 4:10 pm
Mine will go about a month of no use before it dies... I don't use it during winter months, maybe once a month on the trainer, and only to compare Neo vs SRM Watts for accuracy... as someone mentioned above, I also GPS issues...
The last 2 times Ive been in French Alpes staying in Freny d'Oisans I could literally stand on the curb for 5+ minutes before anything would happen.. I lost coverage on the Glandon... GPS satellite is line of sight, but still...
In Maui it seemed to take FOREVER to get a lock, meanwhile my friends Garmin would lock on immediately.. even on the front driveway its an issue some days..
Yep - The PC8's GPS capability sucks! I have been using SRMs since 1998 and they usually get everything right when it comes to straight up power measurement and recording. But GPS - they shouldn't have bothered. It's that bad.

ghisallo2003
Posts: 649
Joined: Mon Jan 02, 2006 7:10 pm

by ghisallo2003

GPS is certainly slow and needs correction in the files considerably more than Garmin. You dont buy an SRM for its GPS capability though.

I switched from Garmin and thought it would just be a trial. I can't imagine going back.

by Weenie


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Calnago
Posts: 8352
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

ghisallo2003 wrote:GPS is certainly slow and needs correction in the files considerably more than Garmin. You dont buy an SRM for its GPS capability though.

I switched from Garmin and thought it would just be a trial. I can't imagine going back.
You can’t imagine going back to a Garmin Head unit? How come if I may ask? I have several SRM Powermeters and all have been faultless with never a spike or dropout. But I’ve never had any desire to get their head units. They just seem so primitive. Played around with setting one up for someone but still there was nothing that would make me want to trade my Garmin head unit for a PC8. I suppose if you were really super duper into analayzing every aspect of your strict performance using software such as WKO+ etc, then it may collect data that you wouldn’t get on other units, but sheesh... all I really wanted was an accurate, reliable clean looking powermeter. The Garmin Head unit, even though it only collects data about once a second, is superb for its display, mapping, gps, configurability, route guidance, and a host of other features that the PC8 just doesn’t have.

But the battery life the OP is experiencing is one thing that shouldn’t be happening. If there’s one thing the PC8 seems to have an abundance of its battery life. Longer, like way longer, than anything else out there. So it seems like something is definitely wrong with OP’s unit.
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