Purion Display Battery

[Ballynoes]

Hi All,
I have the Bosch performance CX motor on my bike, with the Purion display.
After a few weeks of ownership, I switched it off one day after the ride, and the display scrolled "change display battery". No problems there, except I thought, "they didn't last long".
Anyway new batteries fitted, quality ones for info, and first ride with it, same again.
It basically does this every time I switch it off. No affect other than that message.
Not sure weather to bother taking it back to shop.
Thought I would ask here first if others have had any similar issues.

 

[Gubbins]

I didn't think purion it had it's own battery.

 

[Ballynoes]

Sure does two CR2016 watch type batteries.

 

[Gubbins]

Sure does two CR2016 watch type batteries.

Just looked at mine and I cant see anywhere to fit two batteries..
https://www.e-bikeshop.co.uk/Bosch-Purion-Performance-Display

 

[soundwave]

Just looked at mine and I cant see anywhere to fit two batteries..
https://www.e-bikeshop.co.uk/Bosch-Purion-Performance-Display

you have to take it off as underneath and use a coin to remove the batts.

 

[Gubbins]

you have to take it off as underneath and use a coin to remove the batts.

So what do the batteries do? It wont turn on when the bike battery is off the bike

 

[Ballynoes]

The batteries are there purely to power the display, as it is 6v. The bike battery is 36 volts and would fry the display. However you are correct in saying that it does not turn on if the bike battery is missing, I guess this just a security thing.

You can still use the bike with no display (flat batteries), according to the manual, but it suggests against it.

When you power the display off and your batteries are low, it scrolls across the screen "change display batteries" before it goes off.

My problem is, it does this every time, but still comes on the next time... despite putting new batteries in.

 

[Gubbins]

The batteries are there purely to power the display, as it is 6v. The bike battery is 36 volts and would fry the display.

You can still use the bike with no display (flat batteries), according to the manual, but it suggests against it.

When you power the display off and your batteries are low, it scrolls across the screen "change display batteries" before it goes off.

My problem is, it does this every time, but still comes on the next time... despite putting new batteries in.

Good to know.. No probs with that on mine and have been using it for a while now. Only issue I had was the actual pressing of the buttons being a bit hit and miss till I figured out how to do it..

 

[soundwave]

the old display also had a batt but a lion one that was rechargeable and was soldered to the pcb.

it is why you could charge ur phone from it

 

[Ballynoes]

Interestingly, I started thinking about the problem

Why would the display say to change the battery all the time, basically because it thinks it’s below a certain voltage threshold?

All the batteries I have put in are brand new, so the only thing which can be wrong, is an error with the electronics, or the batteries are not making a 100% connection and therefore, more resistance means less voltage, V=IR and all that, from my schooldays.

So I took the battery cover off, used a cotton bud and Isopropyl alcohol (IPA) and cleaned all the contacts and both sides of both batteries, whilst wearing latex gloves.

There are three small brass contacts on the cover, clean all three, and the contact in the middle where the battery sits.

I put it all back together and it worked fine for the 6 or so times I tried it, remembering every time I switched it off before it told me to change the batteries.

Let’s see how long it lasts.

Worth trying, mainly because it’s free.

Here’s hoping.

 

[Ballynoes]

Just an update to say that the problem has NOT resurfaced since doing this clean.... interesting.

 

[Denis99]

Similar issue here.

My Purion display started showing the " change display battery" message on turning the bike off.

Bike had only done 150 miles from new.

Changed the batteries and cleaned the contacts, nothing changed, still showed the same message.

After a week or so, the message disappeared.

Now its back again.

 

[Ballynoes]

I get the impression then, that if there is a fraction of resistance in the battery contact you might get this error. Worth doing the clean as above and see if it goes away. Mine is still working fine since I did.

 

[georgehenry]

Sounds rather annoying. My Yamaha display lets me know when it is time to change the battery by gently fading.