ITTSB.EU Blog Forum
Significant information’s in favor of a professional Workshop => All about Alkaline and Rechargeable Batteries NiMH => Topic started by: Kiriakos GR on October 29, 2018, 07:54:42 PM
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9V Block NiMH market within 2018 it does seems as very problematic.
Reputable brands started excluding 9V Block NiMH from their portfolio, few others keeps this product code at extreme retail pricing, and no-name Chinese factories they sabotage 9V Block NiMH labeled products by a offering of Fake products these including Ni-CD cells instead of NiMH.
Actually NiCD cells are not that bad when these are produced at best specifications, nowadays that Europe banned Ni-CD chemistry, several Chinese factories masking their stock by labeling it as NiMH, and this is another trickery in favor of their own profitability.
Personally after allot of thought I made the decision to not use eBay this time, and to try for a first time this TRONIC (Lidl channel) products.
By choice I never do product reviews of goods which I paid for them.
In my surprise all four 9V Block NiMH they have all ready 12 Months Shelf life, and this is a great opportunity about verifying TRONIC claim of 75% remaining capacity after 12 months time.
For now I will post product pictures and tomorrow I will perform quick capacity evaluation by the use of Ansmann Energy Check LCD (tester).
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Here it comes, first wave of statistics of my four batteries. :)
Steps followed this is measurements after unboxing of Voltage, Recorded Capacity and Internal resistance.
Second step was charging of all four at my Ansmann Charger with four 9V ports, overnight at trickle charge, then batteries stayed seven hours out of the charger and then they were evaluated again.
After 12 Months Shelf life statistics :
Voltage ........Charge Percentage ..........Internal resistance in mOhm at 1kHz
No1) 8.85V ... 100% ... 623
No2) 8.84V ... 100% ... 609
No3) 8.69V ... 100% ... 617
No4) 8.87V ... 100% ... 590
After First charge statistics:
No1) 9.56V ... 100% ... 650
No2) 9.56V ... 100% ... 632
No3) 9.57V ... 100% ... 632
No4) 9.57V ... 100% ... 610
At that time these data are simply reference values from these specific batteries, naturally you may use my data as comparison point if you have proper testing equipment as I do.
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New statistics: 7 years, 9 months, 28 days
Voltage ....Charge Percentage .... Internal resistance in mOhm at 1kHz
No1) 9.56V ... 100% ... 1758
No2) 9.63V ... 100% ... 1130
No3) Dead
No4) 9.54V ... 100% ... 2200
No3) Dead
This cell shown issues in the first year, suddenly this were overheat at the bottom corner, it took me several weeks to understand that one cell did shorted.
The case was slightly deformed, no flames, no holes.
This 9V Block still was receiving a charge and appeared functional for small loads, three years later .... it stopped working.
I am not the only one faced such an incident.
As I found a photograph (from Amazon Review) and from older revision of TRONIC Eco 9V, this one truly burst, deformed plastic case and even opened holes.
At electronics production we do forgive a fail rate of 3%, but in this case a television for example will come DOA, or will fail in the first week.
Rechargeable batteries from the other hand, they need weeks or months, to prove them self's as healthy.
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After 7 years, 9 months, 28 days :)
I have the curiosity to discover how many mAh they hold the alive ones.
I did a quick test at 200mA discharge , 7 V Cut-Off.
No1) 176 mAh
No2) 156 mAh
No4) 151 mAh
No I am looking for a way to do a proper test with 50mA discharging current.
Which this is considered as scientifically correct for a proper capacity measurement. ;)
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The supplier whom sold these cells to Lidl, was a German company that this is now dead.
I did a research, so to find out if my Ansmann chargers (Energy 8 and Energy 16) they could kill a battery with their charging current of 70mA ;D but this is impossible.
TRONIC released few chargers of their own, the production 2017-2018 this was able to deliver 30mA as charging current = Slow automatic charger.