Nicad Battery for 407
 

I've been doing some research for replacement 407 batteries.
I can only find STC's for sealed lead acid batteries (Concorde etc).
While they are the cheaper option they don't last as long so I am trying to find out if anyone produces NiCad batteries or if we have to buy the standard Bell part.

Why buy a battery that is not really designed for aviation ?
A NiCad has a memory effect so should not really be trickled charged, which is exactly what you do with your starter gen after a start
I would stick with sealed lead acid, means if you do flatten it you can take it out and charge it from a normal 24 volt cat battery charger.
Unless you can get a NiMh battery or a LiOn battery which do not have memory effects !

The only NiCad I know of for a 407 is the original Marathon (28Ah) installed by Bell.

You can source the "original" battery from the manufacturer of the battery through FAA PMA and their distributors.

Bell Helicopter 407,427,430

Type TSP-283
Part No. 31908-001
PMA Supplement 50 (7-1-2005)

I once had to replace a battery in an EC135 (SAFT) in the US. Only source in the US was (then) EC. Quoted USD 22K.
Bought one from supplier in EU USD 8K. Released with a Form 1 with all the necessary paperwork for application.

Google the part number you will get a huge response.

I find these guys have a huge selection.
https://www.wes.com.au/

Ah yes WES, the well known aviation battery suppliers :rolleyes:

Thanks for the assistance everyone

You dont want to go the Nicad route, a new Saft 176CH is in the range of $7000, Marathon( if they make one the correct size)would be about the same. The servicing can be expensive, and if more than three cells fail, then you are up for a new battery again.

The Concorde (sealed) is easier to maintain, and if needed in the field could be recharged with an ordinary charger (24V)

Does anyone still actually use Nicads? You can get some fabulous,small, inexpensive chargers to keep on board. Plus you can airfreight Lead Acid batteries, without all the hassle and expense of a Nicad. And don't even start on the maintenance requirements.

Yes. In 407 ops with a high start/flight ratio a NiCad provides a better margin and increased life over the lead acid. Several operators in the GOM tried to switch but went back to NiCad due to start issues, minimum voltage issues, etc. Plus in that environment the lead acids were prematurely failing their capacitance checks, some after just a year TIS.

Most EMS 407 ops went to lead acid as the start/flight was manageable for the lead acid and it added to the reduced DOCs for that type of ops.

Commercial batteries do the job just fine. Odyssey batteries have been fitted under EO approval into 206L/350 and even Lama (Lama draws some serious power when starting) . Throw them away after 12 months , maintenance free and replace for a few hundred $$.

Batteries
 

Batteries are an area I have a fair bit of experience in (renewable energies). NiCd doesn't get the memory effect because they are being trickle charged, they get the memory effect from repeated 'short cycling'. I.e. only taking a portion of their energy before recharging them. In a camera or other consumer device, the solution is simple - regularly discharge them to dead flat before fully charging them. In a chopper, not so easy unless you could swap them out, discharge them on a workbench, and recharge them externally before being swapped back in.

Lead acids... cheap available heavy. They don't respond well to repeated heavy cycling.

It would surprise me that somebody isn't looking at one of the newer battery technologies Li ion etc. Even a NiMh battery would be a better choice as they do not suffer the memory effect that NiCd's do.

That link is for a company that doesn't even sell car batteries, it's a consumer electronics parts shop ;)