History review of Bosch Nickel-Cadmium (Ni-CD) AL60 & AL60 DV chargers

[Kiriakos GR]

This is one last follow-up regarding pulses:

When you do own a special current clamp  (AC/DC with high bandwidth) for Oscilloscope, this is the best tool for this job about pulses analysis.   
Analysis of pulses by trying to trigger over few millivolt (at volts side)  this is a big challenge for any Oscilloscope, but if you do your analysis by looking at electrical current? At that end, electrical quantities they are much larger and your analysis this is at the safe side.

According my latest and final measurements, AL60DV this is very powerful and very smart made product.
Major benefit of a true pulsing charger as is AL60DV, this is that at charging process this keeps Ni-CD batteries cooler (cell temperature) than using constant current by a regular power supply.
In long term, batteries charged by pulsing charger, they will be less abused due heat at charging process.
Additionally now I am aware that when Ni-CD cells they are at low temperature then they are more willing to absorb energy from the charger.

I did also run some tests, so to discover how accurate it is DV sensing feature at AL60DV, and I am now truly surprised of how remarkably accurate this is implemented.   
 

[Kiriakos GR]

This is one follow-up regarding thermistor sensing ability of AL60DV:

By using 1051 Resistance Box (Times Electronics UK) as this to behave as thermistor resistance simulator, I did manage to discover Low & High limits.
Low or High limit, this is a resistance value that internal battery thermistor could be at, and also here is where AL60DV this gets alerted and refuses to operate ( start charging).

Overheat alert: This found to be approximately at 2.05K ~ 2.2K and I am using the word approximately because there is small influence from the actual temperature of the charger it self.
I do not keep my chargers plugged at Mains when they are not needed, therefore when I am up to using them they are cold, from the other hand when a charger is plugged all day long, internal temperature could be 10C above ambient. 

Frozen battery alert:   This found to be at 23K Ohm.
I am mentioning this just for the fun of it,  I am not living in Siberia to worry about : Frozen battery alert 

By all this knowledge that I have now, I can safely come in a first conclusion regarding thermistor compatibility, NTC at 45C and this must measure approximately 2.1K or less of resistance = suitable for operating with an AL60DV.   

More info about Bosch thermistor comparisons will follow later on, when I will receive new PHILIPS thermistor's from Taiwan and also two genuine Bosch batteries (with dead cells) that I got from Germany.

[Kiriakos GR]

I have received from Germany two used Bosch Ni-CD 9.6V ( Knolle ) - Battery pack.

Externally I was unable to identify production date and neither to explain that while both measured zero volts, both they did accept charge and both recovered at 80-90% of usable capacity,  in my places this called as miracle made by God,  or it can also explained as miracle of Japanese technology made in December 1994 =  23 years, 1 month, 11 days.

While I am looking these pictures, I do feel feelings which I have decades to feel, quality of assembly and condition of these cells they look as to was made last year.
All cells has shinny end points, and even this battery pack thermistor it was installed with significant care and caution.

Next to follow will be my study regarding all truth about thermistor value that Bosch have use in these batteries and of how irresponsible their engineers acted back then.   
At this exploration I have spent other than money and also several days of research and also I was forced to assemble one thermistor tester DIY apparatus.

[Kiriakos GR]

Here we have and a second  unboxing     this battery it is made eight months later from the other pack.
According to assembly labels:
6/1994 = older pack
2/1995 = newer pack
Approximately eight months. 
Panasonic logo this is no more and it is now marked as SANYO.

Details:
Cells separation protective pads now has a finer shape, and thermistor this is raped with aluminum tape (foil with adhesive) for better heat transfer.

I have now a master degree (expertness)  at opening cases of Bosch-Knolle battery packs !! 

Currently I am evaluating battery cells chemical condition and remaining capacity of both of these two used packs.
I have all ready one battery pack with new cells at 2000mAh, and therefore from those two used packs I am can accept 1000mAh from its one.



What comes next this is my detailed Charge / Discharge - Remarks and conclusion.