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Product reviews

Hobby King Turnigy AAA Ni-MH LSD Batteries Review

Original article by Malik Salgado, republished with permission under a CC BY-NC-SA license. Some edits have been made to improve readability and aid formatting.

From Hobby King’s website:

Low self discharge AAA NiMH battery. Great for remote devices, camera, transmitters, or other low discharge electronics that you want to use over several months or years without having to recharge.
Low-Self-Discharge NiMH batteries are a new technology that prevent the battery from slowly losing its charge over time. In fact these LSD batteries can stay charged for over a year without losing more than 30% of their charge. Normal NiMH batteries would lose nearly 100% of their charge over 12 months.

Specifications:

Category: AAA battery
Capacity: 800mAH
Voltage: 1.2V
Chemistry: NiMH Low Self Discharge
Weight: 12g
Dimensions: 44.5×10.5mm
We guarantee our cells are true to their capacity!
Sadly battery marketing is an evil game, with overstated capacity being the industry norm. Generally speaking, battery factories will suggest vendors to overstate the capacity by at least 30%, marking 1800mAh cells with 2300mAh labels or more!
While this might work for toy stores, such marketing tactics wouldnt survive 1 week in our store with customer feedbacks and reviews, and thats why we guarantee ourTURNIGY 800mAh NiMH cells to be at least 800mAh!

The Test

Test Equipment:

Turnigy AAA 800mAh LSD Batteries
http://www.hobbyking.com/hobbyking/store/__10899__Turnigy_AAA_LSD_800mah_Low_Self_Discharge_ready_to_use_.html

Maha MH-C9000 WizardOne Charger/Analyzer
http://www.digitaldingus.com/reviews/maha/mhc9000/index.php

Results

Battery NumberInitial Weight (g)Initial 100mA DischargeBreak-in* Capacity (mAh)0.5C Discharge (400mA)0.5C/0.5C Charge/Discharge**
112.0629878852859
212.2624862840848
312.0631859830840
412.0612857826836
612.0631855829837

*Break-in: a 16 hour charge at 0.1C (80mA) (where C is the rated battery capacity), followed by a rest period of 2 hours, then a discharge at 0.2C (160mA), then a 2 hour rest, the another 16h x 0.1C charge.

The charging continues regardless of dV/dt (voltage) or dT/dt (temperature) indicators, which normally indicate ‘full’ charge, and will always proceed for the full 16 hours. The discharge is terminated when the battery can no longer sustain the proper current at greater-than-or-equal-to 0.90 volts.

**Charge/Discharge: Charge at 400mA (which is properly terminated), a 2 hour rest, then a discharge.

Limitations

The charger used was not calibrated. However, it is believed to be accurate, as other MH-C9000 chargers have been compared with calibrated battery test equipment and shown to correlate extremely well.

The total energy output, in mWh, has not been measured. This is a function of the voltage X current X time. A battery with a higher voltage under load (eg. 400mA) will provide more energy than a battery with a lower voltage under the same load.

As the MH-C9000 does not log voltage, nor calculate energy output, no mWh result has been provided. However, based on casual and sporadic observations of the voltage reading during discharge, the voltage can be assumed to be around 1.18V under 400mA load for the majority of the discharge.

Conclusions

The batteries, which are rated at 800mAh, delivered more than their rated charge, at both the IEC standard test (break-in mode) and in a higher-drain test. This indicates that the batteries should perform well under significant load.

The batteries had significant charge upon arrival, which indicates some LSD (low self discharge) capacity. Considering it was at least a a couple of weeks since shipment from Hong Kong, it can be inferred that they do not have a very high rate of self discharge.

However, without knowing how much or when the batteries were initially charged, it is hard to calculate how slowly the batteries self-discharge.

The change in capacity between the break-in and charge/discharge indicates the possibility that more capacity may be gained by repeated cycling.

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SanDisk Cruzer Blade 8GB USB Flash Drive Review

The SanDisk Cruzer Blade 8GB USB Flash Drive was purchased from Dick Smith Electronics on special last weekend for $17.88. An 8GB model for <$20 is a pretty good deal for your standard everyday flash drive – there are higher performance models available for only a fraction more, but they are only available from specialist computer retailers and/or online stores, requiring an additional $5 or so p&h.

The Cruzer Blade package is fairly minimalistic compared to past SanDisk products (Micro, Contour etc). The reverse side has basic warranty information in multiple languages. This model is apparently limited edition, but there seems to be no difference other than the body colour (other models are black). The flash drive measures in at 40 x 18 x 7.5mm (L x W x H). Keeping the flash drive attached to a lanyard is probably a good idea – unlike previous Cruzer models, the Blade is not supplied with one to keep costs down. The body is made of 2 molded plastic shells. Worryingly, the USB connector is molded into the plastic body and may be prone to damage. While it negates the need for an end cap, the connector is prone to flexing when inserting the flash drive into tighter USB ports. The plastic is reasonably flexible so it should survive everyday use with reasonable care. One other thing problem is the lack of a status LED. While modern OS’s allow hot-plugging USB devices,  more than enough people corrupt all their data by removing a flash drive while it is in the middle of a write operation.

I ran the Cruzer Blade through a suite of benchmarks to assess its performance. Long story short, the Cruzer Blade is a fairly average performer. In fact, the previous generation of SanDisk flash drives (Cruzer Micro) which the Cruzer Blade replaces is actually moderately faster. Also, be aware that performance may vary slightly between different capacity models (eg 8GB vs 16GB). With that said, on to the results (click to enlarge):

The first utility used to benchmark the Cruzer Blade is CrystalDiskMark 2.2. A total of three tests are run in read and write mode; 3 repetitions are averaged to give the final result. Sequential represents the maximum achievable speed if you were to copy large files to the drive. Random 512k and 4k are more realistic representations of speeds achievable during daily use. The Cruzer Blade manages a reasonable ~20MB in Sequential and 512K read but slows down significantly with smaller file sizes. As expected, the write speeds are significantly slower.

Next, ATTO Disk Benchmark was used to assess read and write speeds at different file sizes. Attainable read speeds vary from 1MB to 34MB/s, and 357KB/s to 4MB/s for write. The read speeds overall are decent, but write speeds for 16K and lower are lackluster. Performance for 64K to 8MB files is abysmal, clocking in at 2.6MB/s.

The following two tests with Flash Memory Toolkit 2.00 also present a similar story – good read, but poor write speeds:

Finally, HDTune Pro’s random access test is used to assess the Cruzer Blade’s random access speeds:

Once again, these results are fairly average. Portable applications will have no problems running from the Cruzer Blade and basic file transfers will complete reasonably quickly.

So how does the Cruzer Blade 8GB stack up? Overall performance is typical of most commonly available standard flash drives. Good read speeds, but write performance is a let down. Computer enthusiasts won’t be satisfied, but for the remaining 95% of the population, the Cruzer Blade will work just fine for everyday use and still kicks the pants off generic, no-name Chinese flash drives.

Pros:

  • Cheap (2GB models start at $3.99)
  • Small
  • No cap to lose and replace
  • Good read speeds

Mediocre

  • 2 year warranty
  • No lanyard provided

Cons:

  • Fragile plastic connector
  • No status indicator LEDs
  • Lackluster write speeds