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View Full Version : Li-Ion Battery from Robokits- Usage Experience & reliabi



bhishmar
05-15-2009, 09:36 PM
Hi
I want to know if anybody is successfully using the 2000mAH Li-Ion batteries (8.4V or 12.6V) sold by robokits india.
(http://robokits.co.in/shop/index.php?main_page=product_info&cPath=13&products_id=71)
This battery seems to be from LG-Chem: Cylindrical model ICR18650S2, with an orange/rose colored heatshrink plastic-wrap.

How is their performance after repeated charge cycles? How much current can be drawn from it? The robokits-ad claims your can draw 4.0Amps (discharge current).
How much terminal voltage drop is there if you draw that much current, or say 2Amp. Users, pls provide their feedback, along with their experience on its reliability & life.
I am not sure whether this are from LG-Chem or some duplicate.!

hardikcool
05-16-2009, 07:10 PM
i have not used batteries of robokits but the other goods which they sale is standard...so neva got any complaint/.....in batteries i thnk they r a bit costly!

vikas
05-16-2009, 07:57 PM
Yep they have good quality stuff , dont think they would send sell any fakes.

mk
05-16-2009, 10:08 PM
Ive used those batteries. They were my first and till now the last LI-Ion batteries ive used for robotics. They work fine but When I got them, then 1 had got over hot, and I couldn't understand why. It had somehow itself damaged its insulationm and was getting short. So I had to disconnect its terminals completely and make my own insulation. After that they work fine. I'm not too happy with there performance considering the high cost factor. At Lajpat Rai market, Delhi, I was getting similar batteries at very cheap rate from a reputed shop. MY advise to you.. IF you have other alternatives, then try them first.. Because cost is very high, and performance is fine but not too equivalant to cost.

vikas
05-16-2009, 10:36 PM
Where in lajpat rai can you get them ?

Also i think Robokits is selling the Esky charger ( Relabeled ) at a premium , I saw same charger on other sites at Rs 500 ... i think rotor.co.in . Anyhow can we get the charger too in Lajpat rai ? If it was decently priced would have bought from robokits only ...

http://robokits.co.in/shop/index.php?main_page=product_info&cPath=13&products_id=133 (charger = Rs 1200 )
http://rotor.co.in/show-detail.asp?prodid={7B615D33-89BA-4499-ACCC-79710474FACA}&pn=1 ( Rs 500 )

bhishmar
05-26-2009, 04:36 PM
Hi all
Thanks to all ( especially mk) for all the feedback.

@mk: I would like to get some specific information from you.
Can I get some quantitative feeedback rather than qualitative, regarding these Robokits- LG-Chem ICR18650 Li-Ion batteries.
For example
(a) How long you were able to use a pack successfully? (period months)
(b) For a discharge current of say 1Amp, how much terminal voltage drop or actual terminal voltage you are getting? (3.0V - 4.2V)?
(c) The idea is even after repeated charge-discharge cycles, are you able to draw high current, without significant voltage-drop? if so what?
(I know the theory, What i am interested is actual practical experience!)

If you dont have exact details, some approximate values or related information are ok.

Since I live in Kerala, I do not have any other option now, unless otherwise you can point out any other online sellers in india.

Also feedback from any other user is also welcome.
Thanks

mk
07-08-2009, 01:50 PM
Hey, sory for late reply... Im quite sure that by this time you would have already done some arrangements for the battery, but may be this info can be usefull to others.

(a) I'm still using that pack. It depends upon your usage. On keeping unued for 2-3 months also, the pottential didn't decrease much. So, for that part, they're good.

(b) Ive not tried that practically as Ive no means to ensure that discharge current is exactly 1A. However Multimeter showed 4.2A only when the batteries were brand new. After that, they never reached more than 3.5-3.7V

However, i'llsuggest you, that don't go for these. Rather at Delhi, Lajpat Rai market, Shop No.629 has Li Ion batteries which are comparativelly cheap and look better also. Batteries from Robokits.com (Ahmedabad) are very crude to look at, and seems as if they are kind of locally made rather than by some professional or standard company.

asimov_18
07-09-2009, 12:31 AM
Hi all,
I don't really know to what extent this is true . But as far as I am aware all the reputed brand of LI-Ion battery manufacture (LG-chem, Sanyo,sony,panasonic..)don't cell their cell in open market. This is because Li-Ion cell are notorious for catching fire and are Hazardious. Many a times Improper handling of these batteries have resulted in accidents and to prevent and bad reputation to the company because of this these OEM manufacturers only sell battery packs with safety circuits thru special distributors(which don't deal in small volume). So many a times the batteries reaching the hobby folks like us are from old Laptops or old battery pack which couldn't be sold or even spurious battery pack made in China. FYI most of these reputed companies have setups in Korea and Japan and Japan is the Second larges manufacture of Li-Ion cells.


Though this may sound stupid I guess the best source for good quality cells could be Acer/I-ball/HCL Laptops genuine battery as these cell would be genuine and sure to last long. Avoid the premium brand laptop batteries like Sony and stuff as they are way too expensive..

asimov

docel
07-11-2009, 07:25 AM
That specific battery cannot supply 4A. It will overheat and might explode if a 4A load is connected.

It is rated for a continuous discharge current of 1A max.