Experience with StarkPower LIFEPo4 Batteries?

Most of the folks (myself included) who have switched to the LIFEPo4 seem to be using the K2 Energy 12V/10ah with included BMS based on what I see at the charging station at contests. Today, a club member showed me a competing product from StarkPower which is a 12V/12ah including BMS that's about $50 cheaper. I haven't been able to find the technical documentation on either company's Website to do a detailed comparison of their performance specs (especially the discharge curve), but let's assume they are similar. 20% more capacity for 25% less cost seems attractive. Does anyone have any experience with the StarkPower product?

On Monday, April 29, 2013 8:08:01 AM UTC-4, Papa3 wrote:
Most of the folks (myself included) who have switched to the LIFEPo4 seem to be using the K2 Energy 12V/10ah with included BMS based on what I see at the charging station at contests. Today, a club member showed me a competing product from StarkPower which is a 12V/12ah including BMS that's about $50 cheaper. I haven't been able to find the technical documentation on either company's Website to do a detailed comparison of their performance specs (especially the discharge curve), but let's assume they are similar. 20% more capacity for 25% less cost seems attractive. Does anyone have any experience with the StarkPower product?

If you have problems, it won't be with the discharge curve.

Of primary importance:
* quality of internal construction
* cells that can pass puncture / crush & short circuit tests without fire, explosion
* BMS with over charge, undercharge, current limit & cell balancing (not all do cell balancing)

Please shop carefully. There are a bunch of cottage industry companies assembling Chinese manufactured LFP tubular batteries (3.3 V / 3300 mAH are typical) into 12V and 24V battery packs with various electronics to manage them.

I looked at Stark Power. IIRC, the BMS that was offered at the time (these products are evolving rapidly) did not do cell balancing.

I bought a 12V / 12 AH LFP battery from another source that (on paper... I can't open it up to look....) met all my requirements. I did a charge / full discharge test using an instrumented battery charger and it maintained 12V under load through 12.1 AH of discharge at room temperature.

In the glider, it works great. Time will tell.

Evan Ludeman / T8

On Monday, April 29, 2013 8:57:00 AM UTC-4, Evan Ludeman wrote:
On Monday, April 29, 2013 8:08:01 AM UTC-4, Papa3 wrote:


Of primary importance:

* quality of internal construction

* cells that can pass puncture / crush & short circuit tests without fire, explosion

* BMS with over charge, undercharge, current limit & cell balancing (not all do cell balancing)



Please shop carefully. There are a bunch of cottage industry companies assembling Chinese manufactured LFP tubular batteries (3.3 V / 3300 mAH are typical) into 12V and 24V battery packs with various electronics to manage them.


I looked at Stark Power. IIRC, the BMS that was offered at the time (these products are evolving rapidly) did not do cell balancing.


Evan Ludeman / T8

The Stark Website advertises a "complete" BMS (based on what I've seen from the competing products):

SAFETY:

* Internal over charge protection.
* Internal low voltage protection.
* Internal short circuit protection.
* Internal cell balancing.
* Auto Restart function.
* No presence of toxic substances.

I'm happy with my K2s, but with each instrument upgrade the glider is getting ever more hungry for battery power. So, if the Stark turns out to be as advertised, then it may be worth a switch.

FWIW: I ran a discharge test on the K2 when I first got it. Seemed to proved pretty much as-advertised capacity. Haven't checked again with about 6 months of use on it; will do that and see if it is holding up (which the specs say it should).

P3

On 4/29/2013 5:08 AM, Papa3 wrote:
Most of the folks (myself included) who have switched to the LIFEPo4
seem to be using the K2 Energy 12V/10ah with included BMS based on
what I see at the charging station at contests. Today, a club member
showed me a competing product from StarkPower which is a 12V/12ah
including BMS that's about $50 cheaper. I haven't been able to find
the technical documentation on either company's Website to do a
detailed comparison of their performance specs (especially the
discharge curve), but let's assume they are similar. 20% more
capacity for 25% less cost seems attractive. Does anyone have any
experience with the StarkPower product?

I couldn't find a datasheet, either, so I requested one using their
website email form.

I won't buy a battery of this type from anyone that does not have a
comprehensive datasheet for it. For me, that is the absolute minimum
effort they should go to, especially for a relatively new and unknown
company.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl

We bought a couple last fall and had an outside tech person do extensive lab testing before we mounted them in two gliders for continued testing before offering them for sale on our web site. We have now delivered the first shipment and everyone is satisfied with no problems so far.

Tom Knauff
Knauff & Grove Soaring SUpplies
WWW.EGLIDER.ORG

On Monday, April 29, 2013 7:08:01 AM UTC-5, Papa3 wrote:
Most of the folks (myself included) who have switched to the LIFEPo4 seem to be using the K2 Energy 12V/10ah with included BMS based on what I see at the charging station at contests. Today, a club member showed me a competing product from StarkPower which is a 12V/12ah including BMS that's about $50 cheaper. I haven't been able to find the technical documentation on either company's Website to do a detailed comparison of their performance specs (especially the discharge curve), but let's assume they are similar. 20% more capacity for 25% less cost seems attractive. Does anyone have any experience with the StarkPower product?

Tom could you post the results of the independent testing you had done on the batteries you are selling. Maybe it could provide some confidence towards understanding this new battery type beyond just a verbal assurance. There seems to be lots of questions and very little hard evidence on the LiFePo4.. If your independent testing results can validate these products with something more than "I have tried them and they seem to work" it would be a significant step forward to the acceptance of the Stark product or similar products. Not to mention the tenfold cost difference between a SLA and a LiFepo4.

On Monday, April 29, 2013 6:38:05 PM UTC-5, Tom wrote:
We bought a couple last fall and had an outside tech person do extensive lab testing before we mounted them in two gliders for continued testing before offering them for sale on our web site. We have now delivered the first shipment and everyone is satisfied with no problems so far.



Tom Knauff

Knauff & Grove Soaring SUpplies

WWW.EGLIDER.ORG

On 4/29/2013 4:01 PM, Eric Greenwell wrote:
On 4/29/2013 5:08 AM, Papa3 wrote:
Most of the folks (myself included) who have switched to the LIFEPo4
seem to be using the K2 Energy 12V/10ah with included BMS based on
what I see at the charging station at contests. Today, a club member
showed me a competing product from StarkPower which is a 12V/12ah
including BMS that's about $50 cheaper. I haven't been able to find
the technical documentation on either company's Website to do a
detailed comparison of their performance specs (especially the
discharge curve), but let's assume they are similar. 20% more
capacity for 25% less cost seems attractive. Does anyone have any
experience with the StarkPower product?

I couldn't find a datasheet, either, so I requested one using their
website email form.

I won't buy a battery of this type from anyone that does not have a
comprehensive datasheet for it. For me, that is the absolute minimum
effort they should go to, especially for a relatively new and unknown
company.

I regret to say the "datasheet" the company provided is just a copy of
the information on their website: no charts, no temperature characteristics.

These batteries are complex devices compared to the SLA batteries we've
been using for decades, but even the SLAs have comprehensive datasheets
available. I expect even more testing and information from the
manufacturers of the newer batteries that include electronic management
systems.

If the batteries were manufactured by a company with a decades-old
reputation, like Panasonic, Powersonic, Yuasa, etc, I'd be much more
willing to trust them, unfortunately, they come from small companies
with very short histories.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what
you need to know tinyurl.com/yfs7tnz

On Monday, April 29, 2013 11:32:45 PM UTC-4, Eric Greenwell wrote:

If the batteries were manufactured by a company with a decades-old
reputation, like Panasonic, Powersonic, Yuasa, etc, I'd be much more
willing to trust them, unfortunately, they come from small companies
with very short histories.


In the era of same-branded batteries sourced in batches from the lowest bidder in different countries, is it still valid to trust a battery based on the reputation of a long-standing brand name? I think not.

When you test a battery for safety, your results are at best applicable to other batteries from the same batch.

Is there a market for rocket-launched ejectable battery boxes?

On 4/30/2013 9:40 AM, son_of_flubber wrote:
In the era of same-branded batteries sourced in batches from the
lowest bidder in different countries, is it still valid to trust a
battery based on the reputation of a long-standing brand name? I
think not.

I think Sony or Panasonic, for example, have a big incentive to ensure
the batteries that carry their name will not harm their reputation. They
also have the resources to recall and replace defective products. Not so
likely for small, newly created companies.

Reputation and history aren't perfect markers for quality, but what else
do we have to go on? Well, there are the data sheets I can get from the
big companies, but not from the new little ones.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)