Battery at 50% yet power is switching off

[egroover]

Depends if the volatage reading is via a DVM or the lcd 4 ?
My lcd4 isn't vary steady, the static reading can vary by 0.5v.
My current 12s reads 44.9v on my DVM, 44.8v with a lcd3 and then the lcd4 dances up and down it will read anything from 44.4 - 44.8v and this fluctuates continually.

Though I like the lcd4 for it's size, I am seriously considering reinstalling the lcd3 permanently.

I'm using a bafang 500c display and it never shows above 41.8v...dunno where I got the idea only 42v max voltage from for a 36v battery

 

[Nealh]

No, you are correct 36v battery is max 42v.
My readings I posted are because I'm useing 12s /44v nominal batteries.

I used my scenario to to show how vague the lcd4 voltage readout can be

Jody's 43v reading is a tad high for a 36v nom battery, if the reading is a true one then the bms could be at fault and allowing the over charge. If so then it is possible the lcd4 thinks a 48v battery is in use and hence the 50% cut off, if this is the reason why then the battery is at fault.

 

[jodypress]

No, you are correct 36v battery is max 42v.
My readings I posted are because I'm useing 12s /44v nominal batteries.

I used my scenario to to show how vague the lcd4 voltage readout can be

Jody's 43v reading is a tad high for a 36v nom battery, if the reading is a true one then the bms could be at fault and allowing the over charge. If so then it is possible the lcd4 thinks a 48v battery is in use and hence the 50% cut off, if this is the reason why then the battery is at fault.

I tested the voltage after a full charge with digital voltmeter. I will double check as it might have been 42v and I mistyped.
I use the bike daily to take my son to school so since last full charge last night I'm using PAS 3 so will need charging either Mon/Tue unless some of the C setting changes I made today actually make a difference.

 

[Nealh]

There is another possible option that may help and that is a C10 restore/reset of the system.

 

[jodypress]

So a little update. Used the bike today after I'd set C12 to 0 and when riding home just now voltage was at about 37.2v and no cut off. Also battery display is still showing as full.
I upped PAS to 4 then 5 and voltage dropped to 36.6v and no cut out.
Will see how this goes but seems that maybe battery is OK and it is an lcd4 settings issue.

 

[Nealh]

Yes may well be the lcd4 and maybe not a big enough processor in side it, I found my one to be a bit quirky and for now have made a new headset/stem bracket and re-fitted lcd3 tight to the stem.

Good news one is able to see a lower voltage with no cutting out, hopefully one will be able to take it down to 33/34v if need be.

 

[jodypress]

Firstly just wanted to say a big thank you to everyone who's been helping me out with this.

So update this morning. Battery indicator was showing full on ride to school this morning and power cut out just before we arrived. Voltage was about 37v using PAS 3. So on ride home I tried PAS 2 and got to about 50m from my house, seemed to cut off power about 36.9v. I checked battery with a digital multimeter and it read 38.2v so according to chart I found off Google below battery is at 68%. More than enough power to drive a 250w motor I would've thought.

I've not heard back from Ebay seller so will try to escalate directly to Ebay at some point. I'm not prepared to drop another £50 on an LCD3 just to test (also don't have room on handlebars as have a front screen on stem.)
Weird how changing C12 setting has helped a bit but affects battery indicator on LCD 4. I think I might try the C10 reset as Nealh suggested as well.