lipo4 lithium battery

I've got one from Tenergy. Perfect fit (same size as a 9 Ah AGM
battery), about 1/3 the weight, higher voltage and power rating and a
lot more expensive. Would I do it again? You bet!


On 12/31/2014 9:38 PM, shkdriver wrote:
Has anyone adopted the K2 brand lithium as a ship battery?
Praise or Problems? the reduced weight appeals to me.
Scott.

--
Dan Marotta

My Tenergy battery and charger came with a tech sheet which showed the
charging regimen. According to the graph, the charge current drops to
zero when the battery is charged.

So far, I have removed the battery from my glider after flying and
brought it home to charge. On a couple of occasions I've forgotten to
unplug it over night and, on one occasion, for a couple of days. On each
occasion, I felt the battery and the charger and neither showed any sign
of heating. I leave my lead batteries on the Battery Tenders
continuously in the hangar. Maybe next season I'll do the same with the
lithium battery.


On 12/31/2014 9:38 PM, shkdriver wrote:
Has anyone adopted the K2 brand lithium as a ship battery?
Praise or Problems? the reduced weight appeals to me.
Scott.

--
Dan Marotta

On Wednesday, December 31, 2014 8:38:42 PM UTC-8, shkdriver wrote:
Has anyone adopted the K2 brand lithium as a ship battery?
Praise or Problems? the reduced weight appeals to me.
Scott.

I used the K2 LiFePO4 batteries (with BMS) all last year. I also used a battery tester to put them through their paces prior to flying with them. They last about 15-20% longer than my larger and heavier 10.5 Ah SLA batteries and have a much, much flatter voltage profile during discharge. This means they go even longer before you get battery warnings (that is mostly a good thing - though the time from first warning to flat is 15 minutes or less). The flatter, higher voltage profile also makes it a lot easier to slave two batteries together through a pair of Shottky power diodes because the diode voltage drop doesn't reduce useful battery life nearly as much as with SLA.

Nothing but good things to say about them. They are expensive, but worth it to me.

9B

On my third season with LiFePO4 batteries running a full-panel*. I would not go back to old fashioned SLAs.
Phosphate batteries recharge much faster than SLAs, and the charge has a long shelf life.
Jim
*Full VGA display, flight computer, radio, transponder, flarm.

On Thursday, January 1, 2015 8:56:58 AM UTC-8, wrote:
For now, I hesitate installing a very large amp hour LiFePO4 battery required in starting a self launch glider engine. It is a lot of energy in case of a short circuit.

Just for clarity, I am not an expert on this matter, however, it is the advice I have received from people I respect.

Tom

A starting battery need not have a very large amp hour capacity, just the ability to supply a large current for a short time. Due to the cost of the materials, engine start LiFePO4 batteries generally have 1/2 or 1/3 of the amp hour capacity compared to the LA batteries they replace while providing more starting current longer due to lower internal resistance.

A lead acid engine start battery has plenty of energy itself to start a fire - it can produce at least 1500 watts for several minutes if shorted. I don't think there is much difference in safety in this application between LA and LiFePO4. In fact the Lithium is probably safer, since the better ones have a BMS that shuts the battery down in an over current situation.

Regarding using LiFep04 batteries for engine starting. I have sucessfully been using a Shorai 36ah equivalent battery as an automotive starting battery for over 1 year with zero problems. The battery doesn't have a BMS and charges with no modifications to the charging system. Lithium starting batteries we're primarily introduced for motorcycles and race cars but as others have mentiond there are many advantages over lead acid and the costs have come down quite a bit.

EarthX motorsports makes several LiFep04 batteries that have a BMS and cell balancer. These batteries are designed for high amp current draw (unlike the K2) and are designed for engine starting.

Based on the OLC flights of some of the posters, I think I know the answer, but have you had any issues with poorer cold weather performance from the Li than the Pb?

On Saturday, January 3, 2015 12:30:16 PM UTC-8, Auxvache wrote:
Based on the OLC flights of some of the posters, I think I know the answer, but have you had any issues with poorer cold weather performance from the Li than the Pb?

How cold is cold? A good flight where I fly is generally 20 deg F ambient for several hours. I don't know what that translates to where the battery lives on the luggage shelf, but I have had no issues.

Been using the lifepo4 batteries from Bioenno Power for about 18 months. Very flat discharge curve. Works great, no complaints.

Just bought the 9Ah battery and charger was $111.99 ($10 shipping) in the same size format as the "standard" #1290 SLA batteries we all seem to use (used?).

http://www.bioennopower.com/collecti...ifepo4-battery

I ran a K2 LiFePO4 battery I got from FoxOne all last season. My glider really only has room for a PS1270 size battery unless I want to do some extensive fabrication and the LiFePO4 battery fits right into my Walter Dittel battery box. I figured I would need some extra capacity as last year I installed a PowerFLARM core, LXNav Flarmview 57 and LX8080/V5 combo while keeping my Dittel FSG-50. The ship got a couple of pounds lighter, the battery is easier to install - it has to be installed through the control hookup access hatch on the fuselage of my ASW-15 - because of the lighter weight and the battery lasts longer than the 1270 size 9A/H unit it replaced. I kept flying to the beginning of November and there was no noticeable impact on performance due to the cold.