Help! Question for Bafang 850C dispaly owners.

[goral]

Is it nor mal that the display loses the date and time?
Practically after switching off the power supply (not the battery!) the date and time are reset after some time. Other settings remain.
Is this normal or is there something wrong with the display/controller?
Thanks.

 

[guerney]

Is this a recent problem? The same thing happens with PC motherboards when the CR2032 cell or battery pack is depleted or won't charge (evidenced by non-storage of time and date), and the 850C does appear to have one, but this isn't a CR2032:

Bafang 850C display back from the dead

We have used a few different displays with our ebike builds but a common favorite is the Color 850C display. however recently we have had two separate screens die. the first was seemingly after onl…

empoweredpeople.co.uk

Shorting the battery also clears settings (CMOS) on PC motherboards. If that doesn't work, maybe try replacing the battery? If it still doesn't work, maybe the old battery was too depleted the first time to clear settings, and if you want or need to clear settings/reset, you should short the fresh new battery. You never know, it might simply resume storing time and date after battery replacement.

 

[goral]

I am guessing that the issue of losing the date and time is a problem with the power supply to the clock.
I didn't know the display had a battery.
So it's not normal for the display to lose time settings, that's what I meant.
I found the 850C manual on the web where it says that the battery can behave like this and should be charged for 72h, I'll see. If that doesn't help then I guess I'll have to start the warranty procedure, as I don't want to open the waterproof display during the warranty.

Quick follow-up question:
In the display the time is shown in the 12h system.
In the 24h settings
Is it possible to force the time display also in the 24h system?

https://besbike.co.uk/wp-content/uploads/2020/10/Bafang-P850C-manual.pdf

 

[guerney]

I found the 850C manual on the web where it says that the battery can behave like this and should be charged for 72h, I'll see. If that doesn't help then I guess I'll have to start the warranty procedure, as I don't want to open the waterproof display during the warranty.

72h is a long time to keep your bike battery charging, and personally I wouldn't do that because I don't think it's safe. If we don't hear from you, I'll assume something awful has happened.

Quick follow-up question:
In the display the time is shown in the 12h system.
In the 24h settings
Is it possible to force the time display also in the 24h system?

There's nothing about that in the manual. I have a DPC18 display, it's 24 hour representation of time can't do 12h (AFAIK).

 

[goral]

72h is a long time to keep your bike battery charging, and personally I wouldn't do that because I don't think it's safe. If we don't hear from you, I'll assume something awful has happened.

It's about the display battery, not the bike battery.
I don't see anything unusual about keeping the display on nonstop. The only thing is that it can take a little bit of current from the battery - but not any significant amount either. The display, however, is a few milliwatts.
Anyway, I will leave the display on for these ~72h
I hope this will help.
I'll definitely write up if it worked!

 

[guerney]

It's about the display battery, not the bike battery.
I don't see anything unusual about keeping the display on nonstop. The only thing is that it can take a little bit of current from the battery - but not any significant amount either. The display, however, is a few milliwatts.
Anyway, I will leave the display on for these ~72h
I hope this will help.
I'll definitely write up if it worked!

Sorry, I thought you were going to keep your bike battery charging for 72h.

 

[scbk]

Got the same display, mine starting losing the time after maybe 9mths of use, I'd assumed it was the internal battery, and haven't bothered doing anything with it yet

 

[egroover]

Yep same here, there's an internal small rechargeable battery, similar to a PC CMOS battery. They can be replaced if you can find the right one and have the soldering skills. Leaving the display to allways on setting will ensure it keeps the time, but will of course drain the ebike battery a very small amount ( negliable if using and charging bike regularly) ...dunno if leaving the display permanently on will.lead to screen burn ?

I just look at my watch if I want the correct time, failing that, get one of these for 3 quid

Pardon our interruption...

 

[guerney]

This is more readable while riding than my other watches, does 12/24h:

https://www.aliexpress.com/item/1005005554376409.html




It appears available for delivery to the UK when logged in. Was £3 in the great AliExtress Winter Sale of 2023/2024 - hope that's as good or better next year...




Has a (dim) green hued backlight:

 

[goral]

I left the display on for 72h as written in the instructions, and I can see that it has started to keep time.

 

[guerney]

I left the display on for 72h as written in the instructions, and I can see that it has started to keep time.

Good to hear that a bit of the old RTFM helped resolve the problem (Read The Fcuking Manual ). I wonder if the DPC-18 contains a battery... I'll RTFM, if it suffers similar dementia.

 

[egroover]

I left the display on for 72h as written in the instructions, and I can see that it has started to keep time.

I did the same, but I found that even after charging for a few days, after a week or two the clock was out. I guess like all rechargeable batteries, they get to a point where the amount of charge they can hold diminishes. I did read on some forum where someone had soldered on a new battery onto the display circuit board, and i did briefly consider this but couldn't be arsed as the likelihood of me knackering the display completely in process was high.

 

[goral]

I did the same, but I found that even after charging for a few days, after a week or two the clock was out. I guess like all rechargeable batteries, they get to a point where the amount of charge they can hold diminishes. I did read on some forum where someone had soldered on a new battery onto the display circuit board, and i did briefly consider this but couldn't be arsed as the likelihood of me knackering the display completely in process was high.

No problem for me, with soldering (electrionics used to be my hobby a long time ago), but I don't want to open something that has a warranty.
If in a year, when the problem returns, I will either sell this display (buy Bluetooth) or change the battery physically.