Login required to started new threads

Login required to post replies

Don't let your SRM PCV battery die
Quote | Reply
Maybe this is common knowledge but I wasn't aware you needed to keep the Powercontrol charged. I have been riding a winter bike with powertap for the last 6 months. I decided to fire up my PCV this morning so I dragged it out of the drawer plugged it in for a couple of hours and had nothing on the display. I searched for battery replacements and found that the earlier PCVs used a NiMh battery. I found a few potential sources and thought about ordering a couple but decided to take the unit apart first. Inside I found a Lithium battery rather than the older NiMh coin cells.

I asked SRM if there was any way to 'awaken' the battery but was told I would need to send it in for a replacement. Being cheap and not keen on paying $75 to ship my head unit to CO I decided to 'resurrect' the existing battery. I removed the insulating kapton tape, soldered a couple of wires directly to the battery and connected it to a power supply I had lying around. I let it charge at 100mA for an hour or so, verified that the battery voltage had gone up to 4V, disconnected the power supply and plugged the PCV into its normal charger. The screen came back on and I'm back in business.

I'll keep it charged from now on...

Here is the battery used inside my unit in case anyone else needs to recharge a dead PCV:

Quote Reply
Re: Don't let your SRM PCV battery die [gregf83] [ In reply to ]
Quote | Reply
Thanks for the heads up, I did not know that.
I have 2 SRM's (on 2 bikes), one of them has been sitting all winter not used, now I am going to charge it up and hope for the
best.

----------------------------
http://www.instagram.com/cyclewise
Quote Reply
Re: Don't let your SRM PCV battery die [gregf83] [ In reply to ]
Quote | Reply
I'm sure you know this but it is worth noting here, be very careful when charging Lithium batteries. Your average power supply is not a good choice. Thermal runaway is a real issue.
Quote Reply
Re: Don't let your SRM PCV battery die [7401southwick] [ In reply to ]
Quote | Reply
7401southwick wrote:
I'm sure you know this but it is worth noting here, be very careful when charging Lithium batteries. Your average power supply is not a good choice. Thermal runaway is a real issue.
Yes, I should have mentioned I used a current limiting power supply set to 4.2V and 100mA.
Quote Reply
Re: Don't let your SRM PCV battery die [gregf83] [ In reply to ]
Quote | Reply
Good to know. Also worth noting that soldering the wires directly to the battery was/is an operation not to be taken lightly.

Just want everyone to be safe out there. Lithium batteries can get away from you in short order.
Quote Reply