Motorcycle batteries....

[sausageroll]

So ive got this quadcopter builder from the US that I pester for help on Facebook, and one of his freinds uses these batteries.

http://www.shoraipower.com/p-149-lfx12a1-bs12.aspx

Motorbike starter batteries... Very light, 700grams and 12,000mah!! Cheap too. I wonder what the catch is? He seems to think these are the answer. They can provide the current easily enough. ...


Pete.

[Gaza07]

I have to say Pete I really like how you look beyond the norm for better alternatives and solutions 
having just had a look on the net at these packs I think your friend is on to something It wouldn't surprise me if some of the pro gear are using these, the only problem I see is the import duty from America as they are very strict about imports from there and you will always get stung,
I use makita tools that have Lion cells and they have been charged 100s of times and perform better than you can imagine, some thing like this would keep your copter up for ages 
From what I've read they are also contained in a carbon fibre case so they should be strong to, as before with the life packs there maybe some risk involved in trying these out unless your friend is already successfully using these 

Ask your friend for more info or invite him to come and join the forum 

[sausageroll]

http://www.carrotcycles.co.uk/SHORAI-POWERSPORT-LiFEPO4-BATTERIES/SHORAI-LFX12A1-BS12-12AH-12V-CASE-SIZE-1-/prod_1497.html

Well thats the import duty problem solved!!

It seems he uses them in planes. Just asked him how much current his plane draws, id be worried that this is designed for 300 amps for two seconds, not for 60 amps for 10mins. Also wondering how the hell you charge them. If they go in motorbikes, the changes are you just bodge it up to the alternator, surely dosnt use anything special... Will report back.

[sausageroll]

Says on that site can be charged with a lead acid charger. Only downside, this is only 12v but your only loosing 4v.

Wow look at this motherfudger of a battery,

http://www.carrotcycles.co.uk/SHORAI-POWERSPORT-LiFEPO4-BATTERIES/SHORAI-LFX36L3-BS12-36AH-12V-CASE-SIZE-3-/prod_1648.html

36 amp hour!!! Its heavy at 2.2kg but 36ah, that could drive an enormous quad for bloody ages. 300 quid is a lot less than a load of lipos too.


This may really be a good find... Will keep investigating.

[Gaza07]

Bloomin hell look at the  motherfudging price to  Although if you can charge them at 1c then your going to need a 12a charger 

http://youtu.be/-W3Tt0mgRHQ

[sausageroll]

Yeah theres a bit of a cost, but imagine you were buying 34ah of lipo instead.... Thousands of pounds, that big one is 300 quid...

[sausageroll]

My cheap chinese charger thingy will do lead acid at 10amps, thats not too bad, will charge that in just over an hour or so.

I wonder what the discharge curve is like....

[Longnail]

A nice cold day and a hard landing,,, Boom,,, battery acid everywhere..

[sausageroll]

Shorai LFX battery installation on VFR800

Hah, but its not a lead acid, its a LiFePo battery. No liquid in them.

[Gaza07]

There are some warning in the video about using a normal 12v charger, trickle charge is a big no no, I remember a lipo fire a few years back in a garage in the usa it was found his car charger on trickle had passed AC through to the pack and set it off, prob best to stick to LIfe or Lion which are they I thought they were Lion but now I see Life 

[sausageroll]

The guy in that previous video charges it with a 30 quid chinese charger, and its got a balancing port on the battery!! Its like it was made for people like us.

[Gaza07]

I was just watching that its looking better all the time 

[sausageroll]

This one here has the best combo of capacity and weight. 800g for 14ah, thats 2.9 or so of the batteries I currently have and they are 50 quid each and about 600g. This is lighter, buckets more capacity and a bit cheaper. Safer to charge too, and by all accounts, will hold up better in a crash (gotta be better than a silver bag of playdough wrapped in shrinkrwrap).

The only drawback is the voltage is a bit lower. Personally, im not worried about this as im working on about 10 percent power right now to lift itself and two gopros. Im gonna need a massive payload for that 2v change to worry me.

The only thing left to find out is the discharge curve. 14ah sounds great on paper, but if the voltage drops to 6v after half of its theoretical use, then its no good.


Might see if I can bulk buy and rebrand them as RC batteries haha.

[sausageroll]

http://www.carrotcycles.co.uk/SHORAI-POWERSPORT-LiFEPO4-BATTERIES/SHORAI-LFX14A1-BS12-14AH-12V-CASE-SIZE-1-/prod_1551.html

In my excitment, I forgot the link.

[Gaza07]

I think I read yesterday but not syre where now that the Life packs are ok untill you read 90% which should be fine as long as you stick to the 20% rule like with lipo's, Although it is worth verifying before splashing the cash,
Rebranding now that sounds like a good idea  ::)

[sausageroll]

I have just emailed the company to ask how the battery behaves when its being hammered constantly at 60amps rather than doing 100amps for two seconds.

If its LiFePo inside, and people use those already for RC, I cant see it being a problem... As they are so light, and relatively affordable against the alternatives, this really could be a viable solution. I hope it is, a 14ah battery would give us about 25mins of runtime on our current rig.

[sausageroll]

The man from Shorai - he say NO.

Humph.


It also turns out my friend of a friend who said he used them in his plane, he uses them in an actual plane to start the engine, not an RC. Could have been a false alarm, which is a bugger, I was getting excited there.



Hello Peter,

LFX are NOT intended for any application except starting internal combustion engines.  And warranty will not apply if used outside this recommendation.

If you have a motive power need (wheelchair, trolling motor, cpap, robot) these are not what you want. They do not have any low-voltage cutoff to protect the battery, as engine starter batteries do not need that protection (they are rarely discharged more than 25%).  Also note that our LFX36 is rated via a PB EQ system – as equivalent to an 36Ah lead acid - that is completely valid under high-rate application of a starter battery which must supply 11V+ under high load, but is meaningless when used in a low-rate application.  The lithium cells in our LFX18, for example, are 12Ah rated on a 15-minute discharge. (cell capacity of any LFX is ~1/3 of its PbEq rating)

Anyway... if you do want to use the LFX (without warranty), at minimum you would need to get an accurate estimate of average current draw, and use a timer such that the battery always retains at least 30% capacity, with 20% remianing as absolute minimum.  If the onboard control system can measure pack voltage and auto-cut or sound an alarm at 13V, then that would be even better to insure the battery is not over discharged.

Cheers,

[Gaza07]

oh not so good then  probably not worth trying then 

[MadMax]

Sounds like they are admitting that there batteries have no staying power unlike the lead acid they are replacing, I wonder how well they perform on a difficult to start bike, instead of something that fires up on the first flick