[WheresWaldo]

Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here.

---

Two new batteries tested. Even though these were Chinese made batteries, they claim to use Japanese made cells. They also shipped from California instead of China.



You will notice that these are rated at 2000mAh or about 23% greater capacity than the OEM Pentax batteries. At about $9 per battery that should be a bargain. These batteries weigh about the same as the Pentax batteries at approximately 78 grams each. Let's get to testing.

Using the CBA II I ran both batteries through three cycles to make sure there wasn't an issue with the batteries themselves. These cycles were done at a 1C discharge rate to ensure that there were no issues with the individual batteries.

These Chinese batteries were tested with the following parameters:

Battery Type > LiIon
Battery Capacity > 2.0
Battery Voltage > 7.4
Battery Cells > 2
Test Type>Discharge
Cutoff Voltage > 6.0
Discharge Current > 0.5

The Pentax battery was not retested for this round.

I choose a discharge current of .5 Amps as this is what I suspect the average drain from a mix of screw drive auto focus use and internal flash use might average out to and to keep in line with best practice when I tested AA and AAA batteries in the past.

I performed each discharge test about 10 minutes after pulling the batteries off the Pentax D-BC50 charger. The 2000mAh Chinese batteries were consistent and had a power curve very similar to the 1800mAh batteries. The voltage sustainable under load was just a bit less than that of the Pentax OEM battery but not enough to affect camera operation. The consistent readings does indicate that there is some quality control built into the manufacture of these batteries. They are not totally junk. The real truth was revealed when I got the capacity results. Again let me remind everyone that stated capacities are usually measured as a percentage of the total rated output. That measurement is usually .2C or 20% of the rated capacity, so in order to see a reading of 2000 mAh I would need to test them at .4 mAh not the .5 that I did. Because of this we should expect the numbers to be lower. In nearly all the tests I got just over 1400mAh as the actual capacity from these batteries. By comparison the OEM Pentax, rated 23% lower, actually output 1550 mAh at the same current draw or about 6% more power.


Are these Chinese battery worth the cost? Well these two batteries cost me about $18.00 shipped from California. The Pentax battery is currently available from B&H for 46.95 + shipping. Another disappointing purchase if you are expecting these batteries to last longer than the Pentax.

Bottom line: Chinese 2000mAh battery 6% less capacity and 1/5 the cost. Another toss up, you decide.

I also got a back-up charger that I will report on some time in the future.


The attached PDF lists all the battery tests to date. I will update it with my findings on some 1720mAh batteries that have still not arrived. These will most likely be the last batteries I will purchase. If anyone wants their batteries tested for capacity we might be able to figure something out.

Attached Images

NP400_v2.pdf (53.2 KB, 479 views)

[dazman]

Excellent test report. Thank you for sharing this valued information with us.
Can you provide a link to the place of purchase for the 2000mAh batteries tested above.

[mattdm]

These will most likely be the last batteries I will purchase. If anyone wants their batteries tested for capacity we might be able to figure something out.

It'd be interesting to see a test of an old official Pentax battery — one from an early K10D purchaser that's been well-used over the past few years.

[Tom S.]

Excellent information - thanks for testing and posting.

Did you happen to notice any heat issues when testing? Some laptop batteries get so hot they have been recalled as fire hazards. I was wondering if during use or recharging if there were any issues.

Again, thanks!!!

[WheresWaldo]

Excellent information - thanks for testing and posting.

Did you happen to notice any heat issues when testing? Some laptop batteries get so hot they have been recalled as fire hazards. I was wondering if during use or recharging if there were any issues.

Again, thanks!!!

Tom, when discharging at 0.5 Amps there was no heat issue at all, seems the battery never gets beyond a few degrees above ambient temperature. At 2 Amps the batteries warm up but are not hot. I usually have a fan blowing on them while discharging at higher rates to cool them but not at the 0.5 Amp rate. I would suspect that the battery actually runs hotter in the camera because of the confined space.

[WheresWaldo]

It'd be interesting to see a test of an old official Pentax battery — one from an early K10D purchaser that's been well-used over the past few years.

PM sent with suggestion

[WheresWaldo]

Instead of posting directly to the batteries on eBay I will post to the eBay seller that way the links will not become extinct.

• 2000mAh batteries & charger - eBay Store - SuperMart168
• 1800mAh batteries - eBay Store - SuntekStore
• 1750mAh batteries - eBay Store - BT-FLASH

If anyone has any other links please post them here.

[HermanLee]

This is a very good and usable post.

Thanks for doing this, WheresWaldo.
I'm looking for a battery for my K20D and come upon your thread.

Moderatore, can we make useful posts like this as a sticky?

I made my tripod purchase recently from the tripod sticky from Steve last time.

[pingflood]

Just be careful with the no-name batteries. Some of the Canon guys had theirs catch on fire when charging.