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RichJordan
11-05-17, 10:21 AM
Hi,

Met a fellow Skyranger owner last night who has more kit on his Skyranger, but it's also lighter.

Seems like a lighter battery could be an easy way of finding a kilo or two. I've currently got a Varta motorcycle battery, does anyone have the specification of the correct lightweight battery? I think it's called a Red Top?

Are there any downsides to these batteries? I only use the plane a couple of times a month, will it hold charge?

Thanks.

Bob T
11-05-17, 14:56 PM
You mean Motorcycle Lithium batteries?
I took the 3.6 kg Yuasa battery with 180 cranking amps off my Ducati SBK and fitted a Lithium battery weighing in at 620 grams with 180 cranking amps. There are many available for bikes these days and some manufacturers fit them as standard. I fitted a Magneti Marelli one that has been fine for the last 18 months.

andy dixon
11-05-17, 18:03 PM
Obviously not as good as a lithium battery, I have the odyssey battery 106.... a sealed lead acid battery. The manufacturer claims a life of 3-10 years. Average life seems to be 6-7 years.
I've had one on the Quik 912s for 4 years,they don't discharge if you don't use your plane for a few months. They are a bit smaller and lighter, but no where near as light as a lithium that Bob has

The first all red battery is the odyssey the second "red top" is a lithium.

My next battery will be a lithium ( because of the weight and safety of them )

Bob T
11-05-17, 21:57 PM
I have the Odyssey PC 680 in the microlight and that is an AGM battery with loads of cranking amps. I also have in in one of my BMW bikes that needs cranking amps! They are very heavy compared to Lithium.
Odyssey were fantastic a few years ago but these days most bike batteries are AGM and Yuasa is one of the better makes along with Odyssey.

RichJordan
11-05-17, 23:22 PM
Thanks for the the replies all. Lithium sounds like what I want. Current battery is 4kg, so it I can get one that weighs 620gs that'd be an excellent bit of weight saving.

Any preferred brands? Do I just need to match cranking amps?

Bob T
12-05-17, 08:39 AM
Here you go, this one is 290 CCA, more than most bike batteries. You need to choose the CCA rather than the Ah rating which is of no consequence when using is as a starting battery. A High compression V twin Ducati needs around 180 CCA to start it so even a Rotax 912s will have no problems with that and a two stroke would need much less.
https://www.amazon.co.uk/dp/B06XFBFD74/ref=sr_1_8?ie=UTF8&qid=1494574186&sr=8-8&keywords=%22Magneti+Marelli%22+lithium.

goldrush
12-05-17, 09:30 AM
For over a year now, I have been using German motor cycle lifepo4 battery which I obtained as bankrupt stock for 30- a bit more "powerful" (it will actually start my old McCormick diesel tractor!) and at 980gms is also heavier than needed for my 503DCDI Shadow at 350 CCA.

Couple of points.
1. Lipos do not like being charged with lots of "ripple", so with the 503 one needs the "Key West" regulator not the Rotax original. (I believe the 912 regulator is fine)
2. In freezing weather, it will take a couple of seconds for the battery to "wake up" and provide full cranking power... so it probably will not turn over first instance

Bob T
12-05-17, 11:12 AM
http://www.bmaa.org/pwpcontrol.php?pwpID=11830
If the BMAA is going to dictate minor stuff like which battery you can fit then they should keep that up to date. That document is nearly 18 months old - there has been a huge advance it what is available since then.

Bob T
12-05-17, 11:15 AM
Some pictures on here of the weights of some of the batteries that I have in my garage. http://wp.me/p5xJlR-5w

garry
12-05-17, 12:44 PM
Good write up Bob thanks for sharing

Dynaglide
12-05-17, 20:48 PM
Choose a lithium battery with care, for aircraft use. There's some gen on the BMAA website regarding what not to use. It's important enough to be a subject of a minor mod.....
My Nynja came with the option of an Earth-X battery, unbelievable light compared to the old lead-acids I've been hefting into bikes for the past fifty years!
Dave

Bob T
12-05-17, 22:32 PM
Choose a lithium battery with care, for aircraft use. There's some gen on the BMAA website regarding what not to use. It's important enough to be a subject of a minor mod.....
My Nynja came with the option of an Earth-X battery, unbelievable light compared to the old lead-acids I've been hefting into bikes for the past fifty years!
Dave
Why? What will happen in an aircraft that won't happen in a bike? If Ducati are happy to put one in a 20,000 Panigale 1299 then I would be happy in my microlight.

jetlag
13-05-17, 09:27 AM
Choose a lithium battery with care, for aircraft use. There's some gen on the BMAA website regarding what not to use. It's important enough to be a subject of a minor mod.....
My Nynja came with the option of an Earth-X battery, unbelievable light compared to the old lead-acids I've been hefting into bikes for the past fifty years!
Dave

Sadly, my Mcafee has decided that the BMAA is "not safe", baffles me, so I cannot access the files regards what and why not to use certain batteries in microlights. Is it a question of altitude, if so do these batteries come with warning not to ride above a certain altitude for fear of malfunction ?

Having read Bobs info on the batteries, very informative and comprehensive, researched internet views on the technology, the advantages of a dry sealed low weight system and the lack of any seriously negative data, I am baffled. Lithium batteries are not new tech and are found in many items and seem to function rather well unless you decide to drive a nail through them. On my weightshift, Air Creation, the battery is housed within a recess of the fuel tank therefore surrounded by 60ltrs of fuel, is this the problem? Please advise me as until Mcaffee decides otherwise I cannot access BMAA and their collective wisdom.

Arielarts
13-05-17, 11:22 AM
Unfortunately 'lithium batteries' covers a whole range of different chemistrys - some perfectly safe and a few dangerous if abused. You probably carry one or more with you when you fly, close to valuable body parts - think smartphone. The one's we're talking about here are the ones supplied as alternatives to 12v lead-acid vehicle batteries, and are pretty much foolproof.

goldrush
13-05-17, 18:50 PM
Just to add, that the "evidence" is that LiFePo4 chemistry (Lithium IRON Phosphate!!) is "safe" but Lipo (Lithium ION ) is not so safe:-)

Bob T
14-05-17, 08:15 AM
Just to add, that the "evidence" is that LiFePo4 chemistry (Lithium IRON Phosphate!!) is "safe" but Lipo (Lithium ION ) is not so safe:-)

Then I doubt that any manufacturer would make Lipo for motorcycle use.
I wonder what my type my Tablet, phone, GPS or laptop has.

peastlake
14-05-17, 08:43 AM
So if I put a battery (of any chemistry) in my Quik 912S that has a higher CCA number than my existing one, will that improve "first start of the day" performance? This is sometimes poor (and I've had the mags fixed!).

Bob T
14-05-17, 11:08 AM
CCA is cranking amps. We still think of batteries in Ah (Amps per hour) which is irrelevant for a starter battery. Ah is the amount of discharge over time (simply put) that a battery will achieve. In a bike or microlight the battery serves no other purpose than to start the engine, as soon as that engine is running then the generator will supply electrical power.
It Just so happens that the old lead acid technology, which dates back hundreds of years, never had as many CCA as a Gel or AGM battery (more modern) or a very modern Lithium.
One design problem that the Quik has is that the battery is in the front and the starter motor is in the back, so the cables are long, the longer the cable the more the resistance. If you don't want to go for a lithium then chose a Yuasa AGM motorcycle battery as big as you can fit to ensure that you have enough CCA. Yuasa AGM tend to be better quality than all the cheap ones out there and seem to have more CCA per kg in weight.

Dave Morton
14-05-17, 11:29 AM
So if I put a battery (of any chemistry) in my Quik 912S that has a higher CCA number than my existing one, will that improve "first start of the day" performance? This is sometimes poor (and I've had the mags fixed!).

I put the larger cca battery in my Quik s and it made a huge difference, i also replaced the positive cable with a higher quality one and used the old one as a second earth direct to the starter motor, all these little things made a huge difference