Experience with StarkPower LIFEPo4 Batteries?

[Papa3[_2_]]

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?

[Evan Ludeman[_4_]]

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

[Papa3[_2_]]

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

[Eric Greenwell[_4_]]

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

[Tom[_12_]]

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

[glidergreg]

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.

[glidergreg]

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

[Eric Greenwell[_4_]]

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

[son_of_flubber]

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?

[Eric Greenwell[_4_]]

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)

[son_of_flubber]

On Wednesday, May 1, 2013 12:04:29 AM UTC-4, Eric Greenwell wrote:

> Reputation and history aren't perfect markers for quality, but what else
> do we have to go on?

I'll buy that an established source with reputation and history is better than fly-by-night commodity producers.

As to alternatives, look to the small innovative companies that are betting the company on building a safer high energy density battery. For example
http://www.allcelltech.com/technology/thermal-management-with-phase-change-material/prevents-thermal-runaway

What do the smart guys here think of this technology? Does it have merit or is it a marketing gimmick?

[son_of_flubber]

From "Gliding International", May-June 2013, page 57, paragraph 3

"It is not commonly known that there have been three known Lithium batteries (sic) fires within an airborne sailplane producing two fatalities."

[Bill D]

On Monday, May 6, 2013 6:53:10 PM UTC-6, son_of_flubber wrote:
> From "Gliding International", May-June 2013, page 57, paragraph 3
>
>
>
> "It is not commonly known that there have been three known Lithium batteries (sic) fires within an airborne sailplane producing two fatalities."

That statement requires specific citations of national safety board accident reports to be believable. AFAIK, all national aviation safety boards require investigations of in-flight fires so there should be reports on file.

The only reports of in-flight battery fires I can find involve lead-acid or Ni-cad packs.

[Dave Nadler]

On Monday, May 6, 2013 8:53:10 PM UTC-4, son_of_flubber wrote:
> From "Gliding International", May-June 2013, page 57, paragraph 3
> "It is not commonly known"...

"Not commonly known" because it is bunkum...

[Evan Ludeman[_4_]]

On Monday, May 6, 2013 8:53:10 PM UTC-4, son_of_flubber wrote:
> From "Gliding International", May-June 2013, page 57, paragraph 3
>
>
>
> "It is not commonly known that there have been three known Lithium batteries (sic) fires within an airborne sailplane producing two fatalities."

And a couple of pages later there's a brief article extolling the virtues of helium for restoring old gelcoat attributed, of all people, to Tom Knauff.. Oh, and a full page ad for that idiotic VTOL electric pipe dream from Joby. Was this to be a special April 1 issue?

Okay, so no one bats 1000. But the unsourced FUD on batteries is particularly annoying.

T8

[Eric Greenwell[_4_]]

On 5/7/2013 4:38 AM, Evan Ludeman wrote:
> On Monday, May 6, 2013 8:53:10 PM UTC-4, son_of_flubber wrote:
>> From "Gliding International", May-June 2013, page 57, paragraph 3
>>
>>
>>
>> "It is not commonly known that there have been three known Lithium
>> batteries (sic) fires within an airborne sailplane producing two
>> fatalities."
>
> And a couple of pages later there's a brief article extolling the
> virtues of helium for restoring old gelcoat attributed, of all
> people, to Tom Knauff. Oh, and a full page ad for that idiotic VTOL
> electric pipe dream from Joby. Was this to be a special April 1
> issue?
>
> Okay, so no one bats 1000. But the unsourced FUD on batteries is
> particularly annoying.

My Google search for "lithium battery fire sailplane or glider" found
only references to model sailplanes. I'd expect any fire in a glider to
show up on the internet somewhere, especially with a fatality as a result.

So, still unreferenced.

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