Best Buy of Sub-C NIMH Cells with Tabs

[martys]

Does anyone have any buying experience with the quality of Tabbed Sub-C NIMH cells?

I have a Bosch handheld Vac whose 1600mAH battery pac needs replacement and it has a Sub-C NIMH cell shrink-wrapped battery pac that has 13-cells inside.

I contacted Bosch and they want USD $105 (including shipping but not in stock and so no shipping sooner than  two weeks or so).

On the other hand I found many Hong Kong postings on EBay selling tabbed Sub-C cells rated at 6000mAH made by "White High Power" with free shipping from Hong Kong for various quantities at very good prices, for example about $19USD for 10 pieces. 


| see other Sub-C cells offered at even higher prices with capacities such as1600mAH, 2800mAH, 3000mAH.

Lets face it, everything is made in China anyway, so why not pay just 1/3 to 1/6-th the price?

Are these White High Power cells  a good deal, even if I am not a White Supremacist at heart?

Although free shipping involves a slow boat from China, I can wait a max of maybe two months and deal with frequent charging until replacements arrive.

Has anyone  had any experience with White High Power Sub-C Cells?


http://www.ebay.com/itm/10x-Sub-C-SubC-With-Tab-6000mAh-1-2V-Ni-MH-Rechargeable-Battery-White-High-Power-/302080623738?hash=item465568847a:g:gCoAAOSwAuZX18Nc

[tszaboo]

Probably these are 6000mAh, if the chinese hour is only 10 minutes long.

[martys]

Also found some paper-wrapped JapCell" Sub-C 3000mAH locally at approx. USD $6.50-ea. Not including shipping. 13 batteries do put some weight upon shipping costs.

Has anyone used this battery?

[DBecker]

The vast majority of ells on FleaBay have bogus claims about capacity.  They aren't just optimistic, they are outright fiction.

Often they just copy the listing of a competitor and bump the already-exaggerated capacity number up without even checking the other stats.  For instance a 'Tenergy 5000mAh NiMH SubC' that has a fast charge rate of 3000mA for 1.5 hours and a slow charge rate of  300mA for 15 hours.  That's the charge rate for a 3000 mAh battery.  And you'll probably not even get the genuine product, rather the cheapest one made with a counterfeit shrink wrap.

The reason they are counterfeiting that product is because 3000 mAh is the current high end capacity for commodity cells.  Anything better is a specialty product.

[retiredcaps]

The vast majority of ells on FleaBay have bogus claims about capacity.  They aren't just optimistic, they are outright fiction.

I agree.  I have no knowledge in the sub C nimh area, but I have purchased BTY AA cells rated at 2500mAh.  After finally getting a decent nimh charger, the BTY AA cells real capacity are around 250 to 400mAh.

Compare that to genuine eneloops rated at 2000mAh and tested at 1940mAh.

For anything nimh cell capacity on ebay, I look at the rated mAh and drop the last digit for the real measured capacity.  So in your case, I would expect 600mAh as the measured capacity.

[retiredcaps]

Here is a 22 second video showing some generic brand sub C 6000mAh cell at 1296 when fully charged.  The one in the video looks similar to the ebay auction you linked.

So it is double what I expected, but far from the 6000mAh advertised.  For your 1600mAh application, 1296 might be a good fit?

[amyk]

"White High Power" is not the brand, it's the description... white, high power.

There are 1600mAh sub-C on eBay, I would trust those ratings more since they seem realistic.

[martys]

retiredcaps, BTW what is the meaning of BTY? Many Thanks! The cell in the battery charger/analyzer video seems to exactly match the markings of the White High Power cells I am inquiring about.


Many nay sayers but unfortunately no real recommendation of a vendor that offers quality cells showing honest specs and a per-piece price beating Bosch.

DBecker., thanks for pointing out the 3000-mAH is the max. expected capacity for anything but a specialty cell.

amyk, a 1600mAH ratedcell seem more realistic,  but according to to the spec derating of other posters, I then expect actually buying a 1600mAH cell and getting 160mAH capacity?

So anyone who has gotten the real deal, where do  you buy your Sub-C batteries?

[The Soulman]

Did you measure charge and discharge currents in your vac?
If not to high maybe you could convert to common GP brand AA size nimh's?

[edavid]

retiredcaps, BTW what is the meaning of BTY? Many Thanks! The cell in the battery charger/analyzer video seems to exactly match the markings of the White High Power cells I am inquiring about.

BTY is a Chinese brand name.

Many nay sayers but unfortunately no real recommendation of a vendor that offers quality cells showing honest specs and a per-piece price beating Bosch.

Here you go:
http://www.batteryjunction.com/batteries-all.html#/?Catalogproducttype=Batteries&search_return=all&Catalogbattbatterysize=Sub+C

Or, you can buy on Amazon:
https://www.amazon.com/Combo-Tenergy-2200mAh-Rechargeable-Battery/dp/B009WXZMIG

P.S. If you have some electronics knowledge, I suggest buying a cheap battery capacity tester:
https://syonyk.blogspot.com/2015/10/zb2l3-v20-zhiyu-battery-tester.html
http://www.ebay.com/itm/1-5v-12v-Battery-Capacity-Meter-load-discharge-Tester-18650-lithium-lead-ADSD-/172356955122

[martys]

Thanks Soulman, the charger is simply a poorly filtered 31V transformer D.C. wallwart rated at 220mA which corresponds to approx .15C and will only charge the Vac slowly, takes at least 12-hr,  but the charger capacity keeps current low enough to prevent too much damage by overcharge.  I measured the voltage after charging for 18-hr and the battery reads 21.5V and at this point the batteries first seem to get warm, indicating a full charge.

Inside the Vac the charging circuit is simply a 33-ohm/4W resistor in series with the battery pac and a blue LEd indicates charge power is being applied but does not indicate anything else about charging.

I haven't yet measured the discharge current, but the bottom of the Vac case battery cover says 100W-10W, whatever that means, probably falsely promising 100W in use, 10W in charging.  I clearly see markings on the motor 16V.

Seems like the current during operation would be expected to be about 3xC or so, maybe a max of 7-amps running, too much for AA cells. Besides, I would have to use at least 26 or so of them. Seems to be trading many small problems for a bigger problem.

What does anyone think about me starting a post to develop a way to convert this Vac to Li-Ion, like the $700 new models offered by Bosch?

[martys]

Edavid, what good is buying a battery tester if I don't yet have batteries to test, my room is a space growing in dander and dust, and my Vac is out of drift! (OK, I could screw back in the 7-screws and use it to clean up for a few minutes at a time)

I looked at the BatteryJunction offerings and I see  Tenergy NIMH batteries.

But DBecker says, "For instance a 'Tenergy 5000mAh NiMH SubC' that has a fast charge rate of 3000mA for 1.5 hours and a slow charge rate of  300mA for 15 hours.  That's the charge rate for a 3000 mAh battery." Is Tenergy then an honest battery?

[edavid]

Edavid, what good is buying a battery tester if I don't yet have batteries to test, my room is a space growing in dander and dust, and my Vac is out of drift! (OK, I could screw back in the 7-screws and use it to clean up for a few minutes at a time)

It would be so you can test whatever batteries you end up buying.

It's a very small board, you can find room for it.

I looked at the BatteryJunction offerings and I see  Tenergy NIMH batteries.

But DBecker says, "For instance a 'Tenergy 5000mAh NiMH SubC' that has a fast charge rate of 3000mA for 1.5 hours and a slow charge rate of  300mA for 15 hours.  That's the charge rate for a 3000 mAh battery." Is Tenergy then an honest battery?

Tenergy batteries usually get good reviews.

I think those numbers cited by DBecker were just a mistake on the web page he looked at.  Tenergy doesn't seem to have published the correct datasheet, but here is the one for the C size version: http://www.all-battery.com/datasheet/10200_datasheet.pdf

[DBecker]

Tenergy is semi-legitimate.  Which is why they are widely counterfeited.

The Tenergy batteries I buy from Frys are probably authentic, but premium priced for an uneven selection of moderate-spec cells.  The ones sold online are much, much less expensive but run a high risk of being low capacity fakes.  You can't win.