BrendAn Posted June 3 Share Posted June 3 (edited) hi, wondering what the latest consensus is on fitting lifepo4 batteries to aircraft. from what i understand they are safe unless punctured. they are able to be charged by any charging system . i want to use it for my jabiru / xair. 800cca for 2 kg, my battery lead run is over 3 mt and the 270cca agm is struggling. Edited June 3 by BrendAn Link to comment Share on other sites More sharing options...
RFguy Posted June 3 Share Posted June 3 LIFEPO4 batteries wont blow up or fire, but Avoid batteries with built in low voltage disconnect . Having a battery decide to disconnect from the charging system can be VERY bad for the electronics and your airplane, and will also stop you from inflight restarting . avoid on simple , non current limited charging systems , because the lifepo4 battery can drink as much as you can feed it, which ends up overheating the charging system certainly avoid LIFEPO4 battery on std jabiru charging systems. (many people dont take my advice, that's fine) suggest stick with lead acid, they are designed for starting, and do it well. stick with the heavy lead acid because also, your weight and balance is relying on having something heavy in the nose. as for your 3 meter cable issue- you likely need to upsize the copper cross section. simple as that. how much copper is there now ? 2 2 Link to comment Share on other sites More sharing options...
BrendAn Posted June 3 Author Share Posted June 3 47 minutes ago, RFguy said: LIFEPO4 batteries wont blow up or fire, but Avoid batteries with built in low voltage disconnect . Having a battery decide to disconnect from the charging system can be VERY bad for the electronics and your airplane, and will also stop you from inflight restarting . avoid on simple , non current limited charging systems , because the lifepo4 battery can drink as much as you can feed it, which ends up overheating the charging system certainly avoid LIFEPO4 battery on std jabiru charging systems. (many people dont take my advice, that's fine) suggest stick with lead acid, they are designed for starting, and do it well. stick with the heavy lead acid because also, your weight and balance is relying on having something heavy in the nose. as for your 3 meter cable issue- you likely need to upsize the copper cross section. simple as that. how much copper is there now ? thanks glen. i will stick to agm then. i think the cables are 10mm so should be fine. i have read that moving the earth lead to the back of the jabiru starter can help, i will try that. Link to comment Share on other sites More sharing options...
RFguy Posted June 3 Share Posted June 3 I don't think the earth lead on the starter will make any difference. 10mm2 ? OK so 3 meters worth, 100 amps for a 2200 I think , total 10 milliohms = 1 V drop round trip. ((0.01726 / 10 ) * 6 ) .......10 milli ohms is getting down to connection loss. so that should be fine. lifepo4 can help for long cables since they maintain a higher cranking voltage. 1 Link to comment Share on other sites More sharing options...
BrendAn Posted June 3 Author Share Posted June 3 15 minutes ago, RFguy said: I don't think the earth lead on the starter will make any difference. 10mm2 ? OK so 3 meters worth, 100 amps for a 2200 I think , total 10 milliohms = 1 V drop round trip. ((0.01726 / 10 ) * 6 ) .......10 milli ohms is getting down to connection loss. so that should be fine. lifepo4 can help for long cables since they maintain a higher cranking voltage. i may need to get the starter tested too, the brush end of the starter is the only part of the system getting warm after winding it over. battery leads stay cold. it is on the cool mornings that it doesn't like to turn over, Link to comment Share on other sites More sharing options...
BrendAn Posted June 3 Author Share Posted June 3 12V 650CCA LiFePO4 Lithium Motorcycle Battery YTX20 YTX30L Harley davison WWW.EBAY.COM.AU 12V 650CCA. LiFePO4 Lithium. Powersport Lithium. Motorcycle Battery. Battery Type Height: 130±2mm. Width: 87±2mm. Length: 150±2mm. i thought these being designed for motorbikes would have a similar charging system to a jabiru its 650 cca not 800 like i said earlier Link to comment Share on other sites More sharing options...
Tasmag Posted June 3 Share Posted June 3 The big problem with LifePo4, as I see it, is the low internal resistance. When the battery is flat and you jump start it is very easy to overload the regulator, which is what happened to a mates aircraft that caught fire midair. I am a big fan of the LifePo4 but I can't bring myself to put one in the plane, as the charging system is too crude for my liking., Mike 1 1 Link to comment Share on other sites More sharing options...
BrendAn Posted June 3 Author Share Posted June 3 3 hours ago, RFguy said: LIFEPO4 batteries wont blow up or fire, but Avoid batteries with built in low voltage disconnect . Having a battery decide to disconnect from the charging system can be VERY bad for the electronics and your airplane, and will also stop you from inflight restarting . avoid on simple , non current limited charging systems , because the lifepo4 battery can drink as much as you can feed it, which ends up overheating the charging system certainly avoid LIFEPO4 battery on std jabiru charging systems. (many people dont take my advice, that's fine) suggest stick with lead acid, they are designed for starting, and do it well. stick with the heavy lead acid because also, your weight and balance is relying on having something heavy in the nose. as for your 3 meter cable issue- you likely need to upsize the copper cross section. simple as that. how much copper is there now ? what is the actual problem with jabiru charging systems. Link to comment Share on other sites More sharing options...
BrendAn Posted June 3 Author Share Posted June 3 1 minute ago, Tasmag said: The big problem with LifePo4, as I see it, is the low internal resistance. When the battery is flat and you jump start it is very easy to overload the regulator, which is what happened to a mates aircraft that caught fire midair. I am a big fan of the LifePo4 but I can't bring myself to put one in the plane, as the charging system is too crude for my liking., Mike is that the jabiru in 2018, he was lucky to get out of that one. Link to comment Share on other sites More sharing options...
facthunter Posted June 3 Share Posted June 3 Regulating permanent magnet gadgets is a dark art..IMHO. Nev 1 Link to comment Share on other sites More sharing options...
Tasmag Posted June 3 Share Posted June 3 13 minutes ago, BrendAn said: is that the jabiru in 2018, he was lucky to get out of that one. Yep, that was the one. 19 minutes ago, BrendAn said: what is the actual problem with jabiru charging systems. The Jab systems will keep trying to output whatever the battery is willing to take so it doesn't take long for the whole system to overheat and fail. In anticipation of putting in a LifePo4 I added a cut off relay for the output line of the regulator, which would stop that from happening. (As long as Imanaged it before it became a problem) Mike 1 Link to comment Share on other sites More sharing options...
spacesailor Posted June 3 Share Posted June 3 A small wattage globe will keep the generator safe , when the battery disconnects. spacesailor Link to comment Share on other sites More sharing options...
BrendAn Posted June 3 Author Share Posted June 3 mine runs through a powermate , would that help. they are supposed to a top of the range rectifier regulator. Link to comment Share on other sites More sharing options...
BrendAn Posted June 3 Author Share Posted June 3 if i keep the xair i might look at fitting a rotec alternator kit. Link to comment Share on other sites More sharing options...
Tasmag Posted June 3 Share Posted June 3 22 minutes ago, BrendAn said: mine runs through a powermate , would that help. they are supposed to a top of the range rectifier regulator. I purchased a Powermate for that reason, but haven't fitted it. Link to comment Share on other sites More sharing options...
skippydiesel Posted June 3 Share Posted June 3 16 minutes ago, Tasmag said: I purchased a Powermate for that reason, but haven't fitted it. In the immortal words of the fish & chip lady "please explain" - what is a "Powermate" in this context ??? Link to comment Share on other sites More sharing options...
BrendAn Posted June 3 Author Share Posted June 3 just a quality regulator Link to comment Share on other sites More sharing options...
kgwilson Posted June 3 Share Posted June 3 About 18 months my battery died and I needed one quick so went to the local battery shop told them what I had & it was for a Jab 3300 engined aircraft. They sold me a Ritar high discharge battery with 22 amp/hour rating. It was slightly smaller & lighter than the old Motobatt I had but has been great even on cold mornings and after a month or more sitting with no use. Ritar is a Chinese manufacturer that produces all sorts of batteries from small to really huge. It has a design life of 6-8 years and is capable of being fully discharged multiple times. It is a gel lead acid battery. Don't know its CCA rating but it easily turns the 3300 over & the best part is that it only cost $130.00. Have a look at one of these. China is by far the largest battery manufacturer in the world and is leading in battery technology by a long way. 1 Link to comment Share on other sites More sharing options...
facthunter Posted June 3 Share Posted June 3 Gell batteries are good and can be used in any position . Until they are overheated and they then develop permanent bubbles inside and never recover their proper rating. Nev 1 1 Link to comment Share on other sites More sharing options...
spacesailor Posted June 3 Share Posted June 3 Same thing seems to happen with AGM , If they get too hot , they die . spacesailor 2 Link to comment Share on other sites More sharing options...
facthunter Posted June 3 Share Posted June 3 it's the same thing as far as I know. Nev 1 Link to comment Share on other sites More sharing options...
skippydiesel Posted June 3 Share Posted June 3 2 hours ago, BrendAn said: just a quality regulator A brand name Ah! A brand name for a voltage regulator 1 Link to comment Share on other sites More sharing options...
BrendAn Posted June 3 Author Share Posted June 3 1 minute ago, skippydiesel said: Ah! A brand name for a voltage regulator yes, but a with a very good reputation and not all that expensive either. Link to comment Share on other sites More sharing options...
skippydiesel Posted June 3 Share Posted June 3 Hi BrendAn - when I Google "Power Mate" -, I Dont get the regulator you have featured - web site address please. 1 Link to comment Share on other sites More sharing options...
spacesailor Posted June 3 Share Posted June 3 XCOM powermate , ! Aircraft Spruce . Looks similar. spacesailor Link to comment Share on other sites More sharing options...
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