5.2 dreifels charger and controller


Quick Reference

    
Charging Status = red LEDs
- 5 red LED on = full battery (as shown)
- 1 red LED flashing = < 10% charged



    
Charge Display (is on only when connected to electrical outlets)

- 2 yellow LED flashing = discharge before charge, or Battery temperatur too low, or too high
- 2 yellow LED on = charging in process
- 1 green LED on = Battery fully charged


5.2.1. Introduction

The dreifels charge controller is the product of the last five years experiences in battery management. Handling NiCd batteries under most diverse conditions in a very delicate application as vehicle drive is not without haste. The optimal use of the load control chip bq2004 and the capacity measuring chip bq2013 of Texas Instruments/benchmarq has proven on the one hand a maximum life span for the battery cell, exact control for the still available energy and the avoidance of MEMORY effects is made possible by discharge before charge function. The number of possible application profiles is however restricted, that we are grateful over all feedbacks.

Dezember 2001, Ralph Schnyder, info@dreifels.ch

5.2.2. Loading

The loading procedure begins automatically, as soon as the mains cable is plugged. You can pull the cable out approx. 20cm of the battery case. The use of a three pole extension cord is recommended.

· Make sure that the cables and plug are clean and in perfect condition. Bad contacts can lead to malfunctions.

· Always make sure that you use a 3-pole grounded cable.

· The battery charger may be used only with FI switch (available in any electrical shop) protected mains, in order to avoid danger.

The loading procedure begins with 9 minutes charging time with 0.5A. This prevents a premature switching off in the case of old batteries. Afterwards, the normal charging with 2.25A follows until one of the switching off criteria is reached.

- Decrease in electrical power(- data processing)
- Rise in temperature
- Time limit of 5h 25Min

A normal full charge lasts about 3,5h - 4h. Thenafter, a symmetry charging (Top off charge) follows with 0.28A of 76 minutes to adjust the possible capacity differences. Followed by a maintenance charging (Trickle charge) with 0.02A, to balance the capacity losses through self discharge. However, this becomes larger the older the battery gets. The full capacity is only reached immediately after the conclusion of the symmetry charging.

5.2.3. Discharge-Before-Charge

NiCd cells exhibit the so-called "MEMORY effect". This develops, if often times the batteries will not be discharged under 1.1V per cell before charging. The available capacity then decreases and the battery thereby becomes "incalculable".

The effect can be prevented by regular, complete discharge. This method is the only measure that worked satisfactorily reliable with all cells.

However, complete discharge of the baterries are not always possible, and in particular, if you live at the mountain, it is rather strenuous. Therefore, the charge controller possesses an automatic discharge function.

Plug in the mains cable and press the main switch key briefly. The 21W bulb in the battery case turns on and discharges the battery up to 20V. The charging procedure begins thereafter automatically.

In the case of a half-full battery discharging may last up to 4h approximately. If the battery is more than half-full, we advise against the activation of the discharging function, since this will take too much time.

If discharging is briefly interrupted (mains disconnected), then the battery charger changes automatically to the charge procedure.

Without mains voltage the battery cannot be discharged.


5.2.4.1. Charger Display

The battery charger indicates the operating condition with the 2 yellow and a green LED:

yellow LEDS flashing
„Ã Charging ready with high battery temperature or discharge-before-charge

yellow LEDs on
„Ã Charging in progress

green LED on
„Ã Charging is done, Symmetry charging or maintenance charging is in progress

no LED on
„Ã no mains voltage available, transformer overheats or equipment is defective

Capacity- Display LED dreifels charger

LED Yellow

LED Green

No Voltage

Charging in Progress

On

Battery full

On

System check

On / Off

Discharge-Before-Charge

On / Off

Battery temperature too high

On / Off

Battery temperature too low

On / Off



5.2.4.2. Capacity Display

The charge controller is equipped with the chip bq2013, in order to make a reliable announcement of the possible capacity. The chip measures the discharge and the quantity of energy charged and the available capacity is indicated by means of 5 red LEDS.

One LED corresponds to 20% of battery capacity. If the lowest LED flashes means only 10% capacity left.

The chip corrects the errors due to the self discharge and the difference between the outside temperatures can also influence it. When the battery gets older however, this estimation worsens.

Capacity- Display LED dreifels charger

Red 1

Red 2

Red 3

Red 4

Red 5

Charge Status 10%

On/Off

Charge Status 20%

On

Charge Status 40%

On

On

Charge Status 60%

On

On

On

Charge Status 80%

On

On

On

On

Charge Status 100%

On

On

On

On

On



5.2.5. Technical Data

Nominal mains performance 63VA (ca. 0.3A mains current)

Charging current 2.25A

Charging Time ca. 3.5 - 4h

Discharge performance: 12% per Hour (21W 24V bulb)

Charge controller bq2004H

Capacity Display bq2013H

service section: Ringkerntrafo 63VA


6. Tracing an Error and Safety References

The following malfunctionings can occur:

· Charging is aborted early
If the battery case is transferred from a cold environment into a warmer area and starts to charge within 2 hours, the charge controller will switch off the charging prematurely. Because it measures the temperatur of the battery and not the temperatur during charging, and it can not differentiate the relationship between this two.

- Unplug the mains cable out and begin charging again.

- Use a Timer clock and start charging only after the battery has adapted with the room temperature.


· Error activating of the discharge funktion:
Disturbance on the mains i.e. electric power tools, switches, neon lights or battery chargers of other electric vehicles can release the discharge function.

- Place the battery charger as far away as possible from any interference sources.

- screening it after any possible disturbance causer.

· No Functions, driving is not possible:
The main safety fuse 40A protects the Battery for shortcuts. Should this be defective, please send the the whole battery case back for repair and if possible list all the description prior to the occurence of the shotcuts.

We will be informing you as often as possible of occurence of any failures and how to troubleshoot them through our homepage under www.velocity.ch or www.dreifels.ch. We shall be very grateful for any questions and or feedbacks.