Discussion:
Yale MO20S - battery indicator shows sudden battery discharge...

Hi people!

So,a central warehouse has six MO20S and about a dozen batteries that are used every day.
One of MO20S has a problem that after 30 minutes of using truck battery indicator shows the battery is suddenly discharged to 20% and slows down to creep speed..
After several restarts (key on/off) the battery indicator is at 100% again and again after about 15-20 minutes of truck usage battery indicator again suddenly drops to 20% and creep mode is on...
Period between the "drops" are shorter as the battery discharges during use.
When battery is at about 50% of charge it's almost impossible to normally drive the truck,creep mode is always on,battery indicator at 10%...
This happens with any battery that is placed in the truck,all batteries are working normally in other trucks...
This problem is not mentioned in repair manual,i checked all connections,wires etc... everything is ok...

Any ideas what is the problem or where to look for it?

Tnx in advance
  • Posted 19 Jan 2014 07:50
  • Modified 19 Jan 2014 07:52 by poster
  • By DukeLander
  • joined 16 Jan'14 - 34 messages
  • Vojvodina, Serbia
Showing items 1 - 11 of 11 results.
Just to let you know,reprograming with ETACC on Win XP solved the problem.
You need to set battery minimal value from 23.7V (by default) to e.g 22V and everything is ok after that...
  • Posted 21 Mar 2014 22:07
  • By DukeLander
  • joined 16 Jan'14 - 34 messages
  • Vojvodina, Serbia
Mate I was look this vehicle in my base and I also think that you need to do calibration it is my advice.You have my phone if you need advice.I cant be sure is it BDI CURTIS?
Did you look batt adjustment in program?
  • Posted 6 Feb 2014 10:11
  • By nemanja_k
  • joined 15 Apr'11 - 398 messages
  • serbia, Serbia
Of course,I checked all connections,there is no voltage "leak",only thing what is left is the BDI calibration.
I''ll try with Win XP and ETACC app next time...
  • Posted 6 Feb 2014 08:04
  • By DukeLander
  • joined 16 Jan'14 - 34 messages
  • Vojvodina, Serbia
You have changed batteries no change, you have bridged switch out no change, you will have to get your voltmeter out and check where you are loosing the voltage, you may have a bad connection somewhere check voltage across battery, check condition of battery leads for corrosion and oxidated terminals, check voltage at line contractor input side and output side, check for terminals being secure, change line contractor if suspect. Check voltage at fuses ensure there secure and finally check connections at power unit and voltage.
  • Posted 6 Feb 2014 07:31
  • By NER045
  • joined 11 Jan'14 - 137 messages
  • North Yorkshire, United Kingdom
I tried today keyswitch bridging,problem remained.
Tried to connect with ETACC app to calibrate BDI,unsuccessful.
Maybe Win 7 on laptop is problem?
  • Posted 6 Feb 2014 06:39
  • By DukeLander
  • joined 16 Jan'14 - 34 messages
  • Vojvodina, Serbia
Is it posible it's so simple?
I'll try to bridge keyswitch and report back what's going on...

Thank you for tip,Kevin!
  • Posted 30 Jan 2014 08:57
  • By DukeLander
  • joined 16 Jan'14 - 34 messages
  • Vojvodina, Serbia
replace the keyswitch ! had this problem a few times. if you measure voltage at the plug into the back of the bdi it will read less than battery voltage thus giving a reading of flat battery. a quick test i do is to bridge out the keyswitch circuit and run the machine
  • Posted 30 Jan 2014 05:43
  • By kevin_k
  • joined 25 Nov'05 - 502 messages
  • dumfriesshire, United Kingdom
I see now in manual,it says:
"Check that the value of the SET-BATTERY parameter
corresponds to the nominal value of the battery.
Check that the value of the TESTER MENU / BATTERY
VOLTAGE parameter is the same as that measured with
the voltmeter. If it does not match, use the ADJUST
BATTERY function to correct the value."

And this has to be done with ETACC software tool and SST interface cable kit.

I'll check parameters next time when I visit the customer.

Tnx for directions,Nero
  • Posted 20 Jan 2014 14:35
  • By DukeLander
  • joined 16 Jan'14 - 34 messages
  • Vojvodina, Serbia
Hi, under normal circumstances on charging the battery up the BDI would reset it self but if a battery was fit to the truck not supplied by the truck manufacturer then then the battery voltage procedure must be performed on installation of a new battery, if you have a repair manual you may find it in there, unfortunately I don't have that info.
  • Posted 20 Jan 2014 03:06
  • By NER045
  • joined 11 Jan'14 - 137 messages
  • North Yorkshire, United Kingdom
Tnx for reply,Nero

Yes,serial number is: D857T01921J

I do not know about key switch,I was not paying attention on that,I'll check it next time.

How to reset the battery sensing circuit?
  • Posted 20 Jan 2014 02:04
  • Modified 20 Jan 2014 02:05 by poster
  • By DukeLander
  • joined 16 Jan'14 - 34 messages
  • Vojvodina, Serbia
Do you have a ser/no for this truck, it sounds like you have a problem with the battery sensing circuit, dose the key switch feel worn on this truck as it may be prt of the sensing circuit, you may have to reset the battery sensing circuit.
  • Posted 20 Jan 2014 00:59
  • By NER045
  • joined 11 Jan'14 - 137 messages
  • North Yorkshire, United Kingdom

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