# 2S1P 8.4V 3500mAh Battery pack from Kaidomain



## ledoman (Apr 17, 2012)

Recently I've got the pack we were already discussing at the other thread (http://forums.mtbr.com/lights-night...ck-kaidomain-com-reasonable-price-995303.html).

It cames in two version where the only difference is the lenght of the cable.
There is 10 and 60cm cable version:








http://kaidomain.com/bike-lights-an...ble-18650-Li-ion-Battery-Pack-with-10cm-Cable








http://kaidomain.com/bike-lights-an...8650GA-Rechargeable-18650-Li-ion-Battery-Pack

Both cames with wide stripe pouch which was anavalaible at the time pack was sent to me so I might add description later.

*Basic data* 
Battery Cell: *2 x Panasonic NCR18650GA*
Nominal Battery Capacity:	*3500mAh*
Charge voltage:	*8.4V*
Cont discharge current:	*6A*
Cable Standard:	*20AWG with 5.5mm x 2.1mm connector*
Cable Length:	*100mm or 600mm*
Waterproof: *IPX-4 Standard*

So far I've tested capacity and Overcharge/Overdischarge treshholds.

At my standard 2A load I've got capacity *3270mAh* discharged down to 2.6V wich pretty much reflects the cells capacity. Tipicaly capacities are declraed at 0.2C load (ie. 0.7A in this case) which is 1/3 of my test. It is normal that we got less capacity with higher load. Good thing is Panasonic NCR18650GA are designed to support load up to 10A. In a 2S1P setup where load isn't shared between more cells this can be important and there would be less voltage drop. Of course there is small voltage drop over the PCM too.

Here is the discharge curve:







The curve is pretty high regardles of 2A load. Up to 2800mAh where curve starts to decline it still holds 3.25V so with two led lights you won't notice any degradation of light output.

You can see there was some difference between cells. I must say my sample came already charged to some degree (8.24V) and I dont know what happened with it before. It might be used/tested by manufacturer or anything else. There was also 0.01V difference between the cells. To see what hapens during charge process I've recorded also this curves to proves cells muches pretty well.








OK, now some pictures:
























































Good to see there is capton tape used.

Protection module is overkill for this pack confirmed by Archie (thanks for contribution). It uses APM4008N chips with some basic data found here. Those chips can stand much more current than needed. Later on this PCM will probabbly be replaced with ones found in the 2S2P packs.







Desoldered PCM and attached it to the Sanyo 4.35V cells to test tresholds. I've got 4.33V for the overcharge and 2.30V for overdischarge. Since those cells are designed to be discharged down to 2.5V the overdischarge treshold is not to low. Of course 2.5V would be better. On the other side overcharge treshold should be bit lower. Since Panasonic cells are quality ones I think they can stand that charge it is just not very good to them.

Some data for the NCR18650GA cells can be found here: http://www.kaidomain.com/review/NCR18650GA-reviewpage.htm and here: https://www.master-instruments.com.au/cgi/ajax/get_file/63606/1

*Conclusion*:

*Highly recomended*. Those two packs looks very good and can be mounted on the helmet. Specialy 10cm cable version was designed to for such use. They are not completly waterproof, but should stand the rain. For usage on the helmet I would add some grease to the bottom of the pack where it can be opend. This would seal it more, but still leaving posibility to open it.

*Pro:
- high quality Panasonic cells 
- good capacity for 2S1P pack
- cells can stand higher currents
- 20 AWG cable
- rubber sealed pack
- (to) high current PCM
- pouch included
- good price

Con:
- PCM tresholds could be better
- stripes to the PCM and between cells in series could be bit wider
*

2nd Aug 2016: Updated links to the product.


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## -Archie- (Aug 25, 2013)

Nice pack; thanks! :thumbsup:


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## ledoman (Apr 17, 2012)

Side note for 2up light users. Tipicaly most lights with two leds we are using nowadays have unregulated drivers. Since Panasonic NCR18650GA cells have their full capacity discharged down to 2.5V (ie. 5V in 2S setup) you will notice significantly less output before all capacity is used and/or protection trips. So you are already going to know the you are close to the end. This is because voltage from the batteries would drop below Vf of the leds. Good thing with NCR18650GA cells is that this would happen at very end at around 3000mAh or 1.5h of run at 2A load.


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## Ivan87 (Oct 30, 2012)

Can someone please recommend a good charger for this pack? i bought one from Hunk_lee off eBay but it is no longer available? Intelligent Smart Charger DC 8.4V 1.5A for 7.4V Li-ion LiPo Battery Pack AU plug


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## Ofroad'bent (Jul 10, 2010)

ITUO sells a fairly decent charger pretty cheap.


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## slug3135 (Nov 5, 2013)

Anyone ever had luck contacting them when not ordering? I ordered this battery and it's been at this status for a long while:

December 4, 2016 , 1:16 am Processed Through Facility ISC CHICAGO IL (USPS) 

Two emails to kaidomain with no response.


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## ledoman (Apr 17, 2012)

You may also try to contact mr. BanL the KD representative who is member here. I know he is very busy lately, but you can try. Provide order and tracking numbers to him.

BTW, have you checked with USPS since it has already arrived in the US?


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## Dirt Road (Feb 6, 2016)

ISC Chicago is where I ran into problems with this identical pack. That's the last movement the shipment made!Several moths later, I contacted BanL and he got things going. It was worth the wait. Nice 2cell pack.


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## Rod (Oct 17, 2007)

ledoman said:


> You may also try to contact mr. BanL the KD representative who is member here. I know he is very busy lately, but you can try. Provide order and tracking numbers to him.
> 
> BTW, have you checked with USPS since it has already arrived in the US?


I would recommending contacting USPS too.


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## tigris99 (Aug 26, 2012)

Welcome to chicago customs intake. They have had these issues for years upon years.

Email USPS (don't be nice) and go to your post office and have them file an inquiry. Suddenly it will start moving again. They got tired of my phone calls and emails so I think they have list they put me on, because havent had any issues since spring when I called and chewed their asses out. Yeap you can call customs intake directly, post office can get you the number.

That said, USPS in general has been grade a screw ups for the last 3-4 months. Friend of mine building a fat bike keeps posting screen shots on facebook of their idiotic crap. This time we thought I was going ot have to grab his package in st louis while i was down there because it went clear through 2 hubs that are supposed to service our area and back towards central Illinois. He was literally going to call the STL area hub and tell them to hold it that i would be by to pick it up.

Its like as soon as fall hits they go completely stupid. And blame it on "holiday rush" instead of admitting they hand bottom of the barrel morons working in sorting around here.


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## slug3135 (Nov 5, 2013)

Filled an inquiry with usps. Hopefully it will start moving.

On another note is it possible to buy a 2s1p protection circuit used in these cells or something similar? I few a few decent lose cells and don't want to risk drawing them down too far.


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## garrybunk (Feb 12, 2014)

slug3135 said:


> Filled an inquiry with usps. Hopefully it will start moving.
> 
> On another note is it possible to buy a 2s1p protection circuit used in these cells or something similar? I few a few decent lose cells and don't want to risk drawing them down too far.


Sure, see Hunk Lee on Ebay (link to 2S protection circuits, # in parallel doesn't matter): Great deals from A OK battery | eBay Stores . I've used this one (7.4V 2S Li-ion Li-Po Battery Protection Balance BMS PCM Current 7A 2S7AW006 | eBay) in my custom 2S3P 6-cell pack.

This link may help you (link to my pack build): My Bike Lights - Info, Teardown pics, Beamshots, Current Measurements, etc. . . | BudgetLightForum.com .

-Garry


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## Dirt Road (Feb 6, 2016)

Could be a case of customs confiscating the Li ion pack. That's prolly what happened with my shipment last year. Chicago is the worst ISC in the country. Never have a problem with NY Cstoms.


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## derek1387 (Oct 13, 2008)

Does anyone think this would hold up to a Ituo XP3 for helmet mount use? I have the 4 cell pack, but its a bit heavy.

Thoughts?


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## garrybunk (Feb 12, 2014)

I would say yes, but using high mode may drain it pretty quickly. If you use mostly medium (and/or low) and only use high occasionally, then it should hold up. Of course it's only 1/2 capacity, so runtime will be much shorter than a 4cell pack.

-Garry


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## ledoman (Apr 17, 2012)

Based on XP3 review I would say this pack should last about 50min - 1 hour on full. Since XP3 is mostly overkill on full this time could be easily extended using lower modes as Garry said. 
For Hi mode I've put 50 min as starting time since light ought to be regulated which means it pulls more current at the end. Of course I doubt anyone would use it on full that long. It would be better to use some 2 led light (like XP2 or similar) which needs bit less power, weight less and runs longer. Of course this is me....


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## RAKC Ind (Jan 27, 2017)

Did it every time I rode with for 2 seasons. Use high very sparingly. Medium will last a good while. 1.5hr without dropping regulation in medium is longest I pushed it including brief sections of high. Thats riding time, not counting being on low when stopped.

I use the same basic set up before these packs when I go camping and such. Same cells and a fenix case. Dont get a lot of run time but since I dont use high much anyway never a problem for a 1.5hr ride or so.

Sent from my SM-G950U using Tapatalk


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