need help with battery selection

boo

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Nov 10, 2015
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I posted on this subject earlier but got no reply.
Am hoping some knowlegable members will recommend
a good choice of batteries for an Acebeam K70.
I`m ready to order the light but need to order 4 18650 s
to go with it.
Help!.
 

mcnair55

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Have read that post two times.
Cannot find suggested batteries for the K70, only K50 was mentioned, that I saw.

Really don`t understand why someone here will not suggest correct batteries for
the K70.
I went ahead and ordered some. Hope I ordered the correct ones.


May I suggest good quality protected 18650,s,generally batteries are not suggested for makes but watch what the Flashaholics like and use is your best guide.
 

MAD777

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My battery of choice right now is Efest IMR3000mAh 35 Amp flat top purple (unprotected).

See HJK's review about a month ago.

Batteries are subject to individual needs. Some want long runtime while others want high current. Some want only protected.

I buy flat tops & add a neubelium magnet where button tops are required, but others have different methods & many just buy button tops only.

Note: Lithium ion batteries are dangerous in uninformed hands, especially in multi-cell lights.
 
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seery

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Really don`t understand why someone here will not suggest correct batteries for
the K70.

Li-Ion rechargeable batteries are serious business and recommendations should not be made blindly. When asking for advice on batteries, it is usually best to provide some background information to those assisting you.

i.e

Are you new to rechargeable Li-ion batteries? Are you comfortable with un-protected cells? Or do you prefer protected cells? Flat or button top? What type of charger do you use? How will you be using the K70? etc., etc.,.
 

bykfixer

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Li-Ion rechargeable batteries are serious business and recommendations should not be made blindly. When asking for advice on batteries, it is usually best to provide some background information to those assisting you.

i.e

Are you new to rechargeable Li-ion batteries? Are you comfortable with un-protected cells? Or do you prefer protected cells? Flat or button top? What type of charger do you use? How will you be using the K70? etc., etc.,.

Exactly.

It's not like going to a knife forum and enquiring about a sheath for your new Case knife...



It's more like going to a gun forum and asking which bullets for your new Reuger.
 

boo

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Below is a picture of the batteries that I ordered.

http://img.photobucket.com/albums/v434/ice1/xxx _zpsycdgdzce.png

When I first posted asking for advice on which batteries to buy, I thought
no one wanted to help.
After thinking about it for awhile, I realized that people are reluctant to
make suggestions to a nubie because Li-On batteries need to be handled
with care.
I have not been "into" LED lights for very long.
I use a Sunwayman D40A with NiMH batteries.
An Octigon Meteor with 18650 unprotected high drain batteries.
Have used and charged the batteries successfully for a few months
using a XTAR VC4 charger.
I keep the batteries evenly charged and do not let them get too low.
I am sure that some members here are extremely knowledgeable about
Led lights and different kinds of batteries and their proper use and handling.
Just hoping I made a good choice and the batteries will fit and work
properly in the Acebeam K70.

Part of my confusion is that some say they always use protected batteries.
Others say it is a waste of money.
 
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MX421

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As a general rule, most people recommend protected batteries because they have protection circuits to protect the battery and the end user. The protection circuit protects against overcharging and discharging the batteries beyond the safe limits. Going under the minimum charge (typically 2.5 or so) can damage the battery so that it won't hold a charge that well, if at all. Overcharging can lead to overheating, fires, etc (dangerous stuff). There are others more knowledgeable than me, but this is the reasoning behind folks suggesting protected circuits. especially to persons new to lithium-ion batteries). That being said, i've not bought that many protected cells and out of the say 4 or so i've bought, I've had one protection circuit fail already. I've heard magnets can affect their performance or entirely kill them as well (some flashlights have tailcap magnets which is where the protection circuit is) With it, the battery was dead, i stripped it off, and now i run it unprotected, but i know of the dangers and take precautions.

Since most of the dangerous times of the battery are when it is being charged, one of the precautions to take is that you have a charger that has monitoring built in (which your VC4 does) so that it shuts the charging down when the correct voltage is registered. Outside of that, I'd also note the temperature of your batteries and perhaps double check with a volt meter after the battery is off the charger to verify that it holds a charge.

There are many more things you can do, but that's the minimum i do with my batteries. Since i also use reclaimed batteries from tool packs, i also have a even more sophisticated charger that can analyze the battery to determine its usefulness. I recommend you read all you can about using lithium-ion batteries so that you are aware of the dangers. Keep in mind, these batteries are all around us (Laptops, power tools, and even cars) and in most cases are managed correctly and safely, so there is no reason why you can't use them too...
 
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TeaSipper

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You chose wisely. :thumbsup:

Yep, you sure did. I chose Simons myself which is Panasonic made and are double protected.

Good job mate. You did your homework. :)

By the way, With flashlights using more than one cell, protected is the way to go. You could use unprotected but why take chances?
 
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CelticCross74

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as per the Acebeam K70 product page-the K70 requires either high drain unprotected cells or high drain protected cells with 3 mosfet PCB.
 

boo

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as per the Acebeam K70 product page-the K70 requires either high drain unprotected cells or high drain protected cells with 3 mosfet PCB.

Exactly where did you find this information?.
I have looked all over.
ps: What does " 3 mosfet PCB " mean?.
Thanks boo.
 

Crazyeddiethefirst

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Exactly where did you find this information?.
I have looked all over.
ps: What does " 3 mosfet PCB " mean?.
Thanks boo.

I decided to see if I too could find the info-I went to the Acebeam website, searched for K70 and there it was....here is the link:
http://www.acebeam.com/k70-cree-xhp35-2600lm-throw-1300m

I don't mean to sound sarcastic, so I apologize if it came out that way...
 

boo

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I decided to see if I too could find the info-I went to the Acebeam website, searched for K70 and there it was....here is the link:
http://www.acebeam.com/k70-cree-xhp35-2600lm-throw-1300m

I don't mean to sound sarcastic, so I apologize if it came out that way...

I did not think you were being sarcastic.
I appreciated the information.
I clicked on the link you posted. Acebeam must have updated their site.
Have never seen that much information on the K70 before.
Now i`m wondering if I have bought batteries that should not be
used in the K70. $70. worth of batteries I might add.
Still do not know what 3 mosfet PCB means?.
 

KeepingItLight

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Still do not know what 3 mosfet PCB means?.

I am not an expert, but let me share the limited information I have. Hopefully, one of our battery experts will correct me, if necessary, and fill in the details.

The MOSFETs (metal-oxide semiconductor field-effect transistors) are the current channels in the PCB (printed-circuit board) that hosts the battery protection. Each channel can only handle so much current. In order to increase the current that is allowed to pass through the protection circuit, you have to add more channels (i.e., more MOSFETs).

As an example, consider the Sanyo/Panasonic NCR18650GA. The unprotected version is rated for a maximum continuous discharge of 10 amps. The protected version sold at Mountain Electronics, however, the EVVA 3500mAh battery, can only handle around 8 amps before its protection circuit shuts down the battery.

I believe that is because the protection circuit only has two MOSFETs. That is only a conjecture on my part, however, because I am not familiar with the details of its construction.

Here is what Mountain Electronics posts on its web site: "Maximum Continuous Discharge Current (protection circuit limited): 8A (cell is rated for 10A, but protection circuit may trip at 8A+)."

You can see some pictures of protection boards with one and two MOSFETs in the article Is my battery protected? by HKJ.
 
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jonnyfgroove

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If those Orbtronics with 10A discharge capability and Seiko protection circuit are not good enough, I would tell Acebeam where to stick it and get something else.

And why hasn't this thread been moved by the mods to the proper forum? :whistle:

EDIT: Disregard my comment about the discharge current. Reading the manufacturers ad, I thought the cells were high drain. They are not.
 
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boo

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KeepingItLight, do you think the batteries I posted a picture of above will
be safe to use in the Acebeam K70?.
At the present time, it is hard for me to understand some of the technical
jargon. I`m learning more every day but, still not there yet.
I have bookmarked your link to "is my battery protected". I will read it and
try to learn and understand it.
Thanks boo.
 
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KeepingItLight

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KeepingItLight, do you think the batteries I posted a picture of above will be safe to use in the Acebeam K70?.

Sorry to say, I am not really the right person to answer this. I do not own the Acebeam K70, and I don't know much about it. I own only one flashlight that uses more than one 18650, the Nitecore P36, so I have limited experience with multi-battery flashlights like the K70.

That said, I had some fun trying to learn about the issue.

According to the Acebeam product page for the K70, it uses a "4S battery carrier" and has a working voltage of "12V-17V." So the batteries are in series. The input current used by the driver, therefore, will be the same as the current flowing in each battery. Presumably, the driver is some sort of buck driver.

I could not find an Acebeam spec for this current.

CPF member kj2, who is an experienced reviewer, reports being told by Acebeam that the K70 draws 7A. He also asked, and then answered, the same question you have about batteries.

Out of these two batteries, LG INR18650-MJ1 - Sanyo NCR18650GA, which would be the best choice for the K70?
I know both are very similar, but have read the Sanyo's are a slightly shorter. Could that cause connection issue with the K70 battery carrier?

Acebeam told me, the K70 draws about 7A from the batteries so think the Sanyo's are the way to go.

Note that kj2 did not consider the Samsung 30Q in his question. Assuming that the current draw of the K70 is indeed 7A, then, performance-wise, I doubt the Sanyo/Panasonic NCR18650GA would be as good as the Samsung INR18650-30Q. They both can handle the current safely, but, at 7A, the 30Q probably sags a little less under the load.

Using HKJ's battery comparator, I was able to verify this. The NCR18650GA I chose for this comparison was the protected KeepPower 3500mAh battery.

Samsung_30_Q_vs_Keep_Power_3500m_Ah_at_7_A.jpg


The Orbtronic 3500mAh may provide performance similar to the KeepPower 3500mAh. That, however, is not the battery you purchased. You have the Orbtronic 3400mAh battery.

If we again assume that the 7A figure is correct, I do not think the Orbtronic 3400mAh battery is a good choice for this flashlight. That battery is built around the Panasonic NCR18650B. Orbtronic has the NCR18650B incorrectly spec'ed at a maximum continuous discharge of 6.8 amps. The manufacturer, Sanyo/Panasonic, posts 4.875 amps in its battery specification.

Orbtronic posted its own "derivation" of the maximum continuous discharge current for the Panasonic NCR18650B battery. Evidently, Orbtronic did not have access to the manufacturer's specification for this battery. That is why it made its own "calculation."

Based on an assumption that the maximum continuous discharge current is 2C, Orbtronic incorrectly obtained a 6.7-amp maximum. The datasheet cited by Orbtronic, however, never explicitly states that the maximum continuous discharge is 2C.

Below is an excerpt from the manufacturer's specification showing the actual maximum to be only 4.875 amps. Note that the datasheet cited by Orbtronic is a different one that does not explicitly provide the maximum continuous discharge current.




Panasonic_NCR18650_B_Battery_Specifications_excer.jpg

Panasonic_NCR18650_B_Battery_Specifications_excer.jpg


Unfortunately, I do not know which protected 18650 batteries use the three-MOSFET protection circuit mentioned by Acebeam.

I wish I could help more, but this is about all I could find.
 
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