5th year of living dangerously with LiFePo4 batteries

On Wed, 06 Jun 2018 09:38:36 -0600, kinsell wrote:

Richard had an interesting post a while ago, where he accidentally used
the wrong charger on an FLP, and battery was destroyed due to swelling.
So much for the idea of a BMS protecting the battery.


Using the wrong charger, or a multi-chemistry charger on the wrong
setting, can destroy any battery, regardless of its chemistry.

A BMS probably won't help here because the charger may not trip the max-
voltage switch and the charge balancer is only there to bring any cells
that are under- or over-charged into line with the rest.


--
Martin | martin at
Gregorie | gregorie dot org

One example does not prove all BMS cannot protect the battery.
I see no eveidence that Life is any more prone to failiure than SLA gell cells.

On Wednesday, June 6, 2018 at 4:25:03 PM UTC-7, wrote:
One example does not prove all BMS cannot protect the battery.
I see no eveidence that Life is any more prone to failiure than SLA gell cells.

If we are rejecting all batteries that can be damaged by connecting to the wrong charger, then we are left with nothing. You can make an SLA explode rather dramatically doing that.

On 06/05/2018 03:44 PM, Martin Gregorie wrote:
On Tue, 05 Jun 2018 21:06:06 +0000, Jim White wrote:

Buy one with a fuse built in?

Yes, but preferably one with a low voltage cut-off and cell-balancer for
charging as well.

But what I was pointing out is that a year or so back there were brands
that were very similar from the outside and (in some cases) had similar
prices. Some of these had BMS fitted and some just had cells wired to the
terminals. Often the descriptions didn't mention whether they had a BMS
or not.

What I want to know is whether this undocumented mess is still the case
or if you can now read published descriptions and know, with a fair
degree of confidence, whether there is or is not a BMS and current
limiter inside without having to chop the battery open to find out.

If the adverts now give reliable information about this, then I'll
investigate further: if not, I'll stick to SLAs for a while yet.



So has anybody gotten specs out of K2? They don't publish them openly,
but instead require that you register and request them. I did that and
they never replied. Maybe they blacklist anybody who can actually read
spec sheets.

Latest info is that due to this battery fire glider manufacturer (Binder) no longer approves or installs lifepo batteries on their gliders. Not sure if AD is in the works.

On 06/17/2018 01:18 PM, krasw wrote:
Latest info is that due to this battery fire glider manufacturer (Binder) no longer approves or installs lifepo batteries on their gliders. Not sure if AD is in the works.


Thanks for the update. I understand this was an EB-28 in Finland.

On Sunday, June 17, 2018 at 12:18:53 PM UTC-7, krasw wrote:
Latest info is that due to this battery fire glider manufacturer (Binder) no longer approves or installs lifepo batteries on their gliders. Not sure if AD is in the works.

Any chance of learning what make and model of battery was in the EB28, so others flying with those particular batteries can be aware?
Jim
It's 7 years for me, Jon.

On Sunday, June 17, 2018 at 12:18:53 PM UTC-7, krasw wrote:
Latest info is that due to this battery fire glider manufacturer (Binder) no longer approves or installs lifepo batteries on their gliders. Not sure if AD is in the works.

Any details at all about the incident would be interesting to everyone......

There is nothing about it on the Binder website.

On Monday, 18 June 2018 03:37:20 UTC+3, JS wrote:
On Sunday, June 17, 2018 at 12:18:53 PM UTC-7, krasw wrote:
Latest info is that due to this battery fire glider manufacturer (Binder) no longer approves or installs lifepo batteries on their gliders. Not sure if AD is in the works.

Any chance of learning what make and model of battery was in the EB28, so others flying with those particular batteries can be aware?
Jim
It's 7 years for me, Jon.

I don't have that info, but it is probable that battery cells were ok and fire was caused by BMS circuit board. I have opened Aeroakku.com lifepo (sort of respected german seller that markets their products for aviation use). It contained chinese BMS circuit made of cheapest parts. Reason I opened it was that BMS electronics failed totally after 1,5 years use. It is very difficult to know what you get when purchasing lifepo batteries.

.....which begs the question - which manufacturers of LiFePo batteries can be relied on to be using high quality electronic components in the BMS?