Battery for a Rotax 912ULS

[ozzietriker]

Hi fellow Aviators,

 

I need to replace my battery. I cannot get this battery here in Australia. Can anyone suggest an effective equivalent make and model to the one pictured?

 

It is fitted to a Magni M16 Gyrocopter, with Rotax 912ULS 100hp - so it would need to be a sealed unit and able to withstand high frequency airframe vibration in flight i.e marine grade. Been to some battery shops in town and they're not helpful.

 

Any info would be appreciated.

 

Cheers

 

Andrew

 

 

 

[cscotthendry]

Helpful tip #1

 

Whenever you go to buy something like this, don't tell the retailer it's for an aircraft. Reactions will range from stunned vacant looks, to being ordered out of the shop.

 

But seriously, if you need an exact "to specifications" replacement, best to get the full specs on sizes capacity etc from the manufacturer, then go shopping for the specs rather than "I need a new battery for my gyro".

 

 

[philipnz]

I replaced my battery last year. Just googled the numbers on the old one and a match came up at a regular car/bike battery retailer. Marshall Batteries. It's a standard motorcycle battery. Had to give them an hour to charge it as they only put the chemicals in on sale.

 

 

[DrZoos]

Are you 24 or 19 rego

 

If 19 then lots of 12v 8ah batteries will be fine

 

I just ordered my replacement from BatteriesDirect in sydney also Battery Dr has them

 

BCR-0859-1008

 

There are a lot cheaper types eg:

 

RM12-9FR

 

not sure on the cranking amps??

 

 

[Yenn]

That looks like an Odyssey in shape and they are used with rotax powered planes. I have found Odyssey to be poorer quality than they imply with their advertising and am using a full rivers battery from Batteries Direct. It is the same as an Odyssey as far as i can see, but I can't say if it is as good or better than Odyssey, but it is half the price.

 

 

[Downunder]

OK. I replaced my "chinese" battery for my 912 uls with an ODESSEY.

 

First I matched the weight. (Important) This give me the pc625 battery at 6kg. Then checked the terminal orientation/ size and overall dimensions. (Will the cables reach? Lug hole size?)

 

All good.

 

Purchased from 4wdextreme on ebay. Was the lowest price plus free express delivery. Had it in 2 days.

 

Slight mod to the tray as it was a bit wider but has been great for a couple of years now.

 

 

[Litespeed]

Don't forget to make sure it has the bolt down terminals like the original- not the crappy car type ones that oxidize and cause all manner of grief.

 

If you wish to save some weight you could always look into a lithium polymer battery. All the rage in sportsbikes these days and you would swear it is a empty plastic case. But damn do they have a lot of grunt. Also used in race cars etc.

 

On something like a old Moto Guzzi or BMW twin it saves about 8kg and a heap of space.

 

They also have the added benefit of keeping charge- no flying for six months? no problems it will still have about 98% charge.

 

 

[Litespeed]

Here is the equivalent lithium polymer battery to suit your need of 300 cold cranking amps

 

LFPUQ-9

 

It weighs 1.7kg total

 

And another at 320 cca

 

and 1.1 kg

 

LH9-B

 

 

[DrZoos]

Litespeed , I looked at these lithiums as I really like the weight savings, and I was going to get factory permission, however, I just decided too dangerous at this stage. I want to see many others try them first... If a company like Samsung can get it so horribly wrong, I don't think many of us stand much chance flying with one, just yet. I know this is a highly debatable topic, Im just expressing my concerns, which may be too conservative.

 

A lot of the sports car guys are doing them as well.. The toyota 86 enthusiasts do them on mass, as they need front weight savings to balance the car, and the battery is the easiest cheapest huge weight saving.

 

 

[Yenn]

Some of the lithium batteries can't stand the charging system on some engines, including some Rotax.

 

The charge is by very high voltage but for very short periods of time. it seems lead acid batteries can handle this, but not some lithium.

 

I am no expert, but would advise doing some homework before going to lithium. Some may be OK, but some definitely are not.

 

 

[Litespeed]

AS far as I am aware- these motorcycle type lithium batteries are a completely different set up to the nasty flammable Samsung type and that is a issue of them overcharging to the point of combustion. The phone use its own circuitry to manage the charge- but the bike type battery has a internal circuit to manage it all.

 

The bike style ones are chargeable by the normal car type chargers, alternator rectified systems etc that have charged lead batteries for years.

 

They do however not accept being charged by the model type lithium chargers- that model aircraft use and by high impulse chargers- which is what Yenn means I think. Why rotax might use this type of system I do not know. I thought it was just a normal AC alternator then a rectifier charging circuit.

 

 

[Head in the clouds]

The Rotax charging circuit isn't a high voltage or high impulse, it's a normal charging/accessories circuit rectified and regulated to 13.2V. The problem that some Lithium batteries have experienced is that the charging accessories circuit on the 912 is capable of delivering 22A which is a bit high for any lithium battery below 22AH. Most of the batteries fitted to 912 powered aircraft are about 18AH, so their max charge rate shouldn't exceed 18A. (Most brands of lithium batteries below 30AH can be charged in Amps, at the Amp Hour rating of the battery i.e. 10AH charged at 10A, 15AH at 15A etc, above 30AH it increases a fair bit).

 

The problem only comes about when you don't have any load on the accessories circuit and the battery is also partially discharged, so all of the available current is going to the battery. The solution is quite simple, keep some load on the accessories circuit - enough to keep the available current going to the battery less than the charging capacity of the battery. This can be done by leaving a landing light (or similar) on permanently - but you'd better keep an occasional eye on the ammeter to notice if the globe burns out sometime ... or you can install a permanent load on the circuit - a wire-wound resistor for example. Or you could have the wire-wound resistor on a switch, so that you can switch it in or out of the circuit according to other load that you may or may not be using. Better still, you could install a wire-wound rheostat (variable resistor) so that you can adjust the load on the circuit at will. Note that wire-wound resistors and rheostats do get very hot so they should be installed where they won't cause a fire, and preferably be ventilated to cool them.

 

 

[DrZoos]

Heads, is there a way to make this relatively fool proof and safe without any pilot input or decisions?

 

 

[Head in the clouds]

Heads, is there a way to make this relatively fool proof and safe without any pilot input or decisions?

Yes, install a Lithium Iron, that's IRON, not ION i.e. LifePO4 (lithium ferro phosphate) battery of more than 22AH then it can be charged at the full 22A capability of the charging/accessories circuit. I'd use a 25AH.

LiFePO4 batteries can't catch fire anyway and are only 10% heavier than the dodgy Lipos (lithium ion polymer). A 25AH LiFePO4 weighs 1.2kg compared with 9kg for a lead acid.

 

Incidentally though, the lead acid batteries of this size shouldn't be charged above about 10-12A either, it's just that they don't catch fire if they're charged too fast, instead they can boil and reduce their electrolyte level and certainly buckle the plates and reduce their life significantly.

 

EDIT - the above is my opinion only, not my advice ...!

 

 

[DrZoos]

Yeh my Cyclon is"supposed" to have a 15 year life... the aircraft is a 2013 model...so it hasn't made 3 full years yet. SLA too my knowledge..not impressed, but needed a quick 24 rego identical replacement

 

 

[Geoff13]

Having been in an aircraft that filled with Electrical smoke, I will happily take the 7-8 kg weight penalty and not be worried about in flight fire.

 

Trust me when I say a smoke filled cabin is about the worst thing you can imagine.

 

Hell I would take a 20kg penalty rather than relive that 10 minutes of my life.

 

 

[Litespeed]

Geoff your problem is a fundamental misunderstanding of electrical systems.

 

Don't you know your electrical system was stuffed- it must be you let out the majic smoke:rofl:Lord Lucas Prince of Darkness invented such a system.

 

In seriousness just use a Li-iron battery and no smoke problems exist.

 

Yeh my Cyclon is"supposed" to have a 15 year life... the aircraft is a 2013 model...so it hasn't made 3 full years yet. SLA too my knowledge..not impressed, but needed a quick 24 rego identical replacement

SLA are in fact not sealed at all- they have a cover that can be removed carefully and underneath it has caps- one per cell- so six in this case. It probably was overcharged by the system and lost some fluid and hence died a thirsty death. You can add some proper fluid and recharge it back to life- I have done this on many SLA batteries. But do not overfil or overcharge or it will boil off the fluid.

 

 

[DrZoos]

SLA are in fact not sealed at all- they have a cover that can be removed carefully and underneath it has caps- one per cell- so six in this case. It probably was overcharged by the system and lost some fluid and hence died a thirsty death. You can add some proper fluid and recharge it back to life- I have done this on many SLA batteries. But do not overfil or overcharge or it will boil off the fluid.

Mine is made up of smaller sealed cell batteries "apparently".

 

They make them up using the smaller Enersys batteries on this page..

 

 

[Captaincoop]

Having been in an aircraft that filled with Electrical smoke, I will happily take the 7-8 kg weight penalty and not be worried about in flight fire.Trust me when I say a smoke filled cabin is about the worst thing you can imagine.

Hell I would take a 20kg penalty rather than relive that 10 minutes of my life.

What caused the smoke?

 

 

[Captaincoop]

Here is the equivalent lithium polymer battery to suit your need of 300 cold cranking ampsLFPUQ-9

 

It weighs 1.7kg total

 

And another at 320 cca

 

and 1.1 kg

 

LH9-B

I use the next one up from this on my 912ULS. I did plenty of research beforehand. 700 CCA kicks it off nice. The weight went from 7kg to 1.7kg and improved C of G.

 

I have flown 150 hours with it. They are the only ones I know of that are ok for aircraft.

 

 

[Geoff13]

What caused the smoke?

http://www.recreationalflying.com/threads/incident-13-may-15.136397/

 

 

[skippydiesel]

I am using a motorcycle SSB Power Sport XR Series battery Part Number RB16CL-B

 

CCA: 385

 

AMP Hours: 19

 

Net Weight: 6.60KG

 

Supplied by "All Purpose Batteries" (02) 46483111 - www.ssbpowersport.com.au

 

Check out the web site they have a vast range of battery configuratioins

 

 

[DrZoos]

I am using a motorcycle SSB Power Sport XR Series battery Part Number RB16CL-BCCA: 385

AMP Hours: 19

 

Net Weight: 6.60KG

 

Supplied by "All Purpose Batteries" (02) 46483111 - www.ssbpowersport.com.au

 

Check out the web site they have a vast range of battery configuratioins

Wow 19AH, why so huge???

 

Dump 10AH and go about 2.8kg

 

 

[skippydiesel]

Wow 19AH, why so huge???Dump 10AH and go about 2.8kg

Firstly : I am a big believer in plenty of cranking amps. Low amps places damaging stress/elevated temperatures on the starting system. My 912 (100hp) starts from cold without any hesitation but on a warm day can have "vapour lock" which can necessitate additional seconds of fast crank to overcome.

Second : This battery is dimensionaly within my aircrafts battery cradle space.

 

Third : Is much lighter & powerful than the original, so I have a win win situation while still maintaining acceptable W&B

 

 

[DrZoos]

always better to be too big then too small, it just surprised me as we have found 8ah fantastic..