Hi Patrick,
I will have to be honest and say I have never tried Duralites. My warning is aimed more at preventing unautorized mods to the system. There is in fact no harm in using Li-Ions as such but based on data at my disposal at the time the state of the art was still in favour of Nicads in terms of current versus voltage. If the KS system is not happy with the battery supply it will respond appropriately. We get up to 10 starts from a 1700 Sanyo pack with a KS and Nicads are low risk in terms of charging. Hence I still use them...
Hope this clears it up for you. I would be glad to get feedback on the use of the new generation Li Ion packs in autostart apps.
Cheers
Andre
MD BMT

Hi Andre:

The charging capabilities of your system seem like a very good idea. I do have one comment thu. If customers use NIMH or LI IO batteries for their ECU's and their RX's, then the charging program has to be changed to accomodate the different battery systems out there. Right now we have Nicads, Nimh, Li Io and Li Poly that I know of. So there will have to be at least four charging profiles in memory.

I Look forward to checking one of your turbines soon if Gordon gets one

hi andre

about lithium battery,s

i am trying these now for about 8 weeks

currently used on a wren autostart with fadec
and my own 8.5n engines also with fadec

they seem to work very fine

i use 2 cells (weight 130 grams) to have full autostart
the size (half the size of a marlboro package)
and i use a special charger for this that is delivered with each lithium pack
the price difference between nic or nmh is next to none!

so i guess this will be next to lose weight
and charging problems , since they dont have a memory problem at all

reg Sandor

Ehab,
I may have to look into Li Ion for the future. To add another charge option is pretty easy for the end user. we send out the code via e-mail and you download it into the TCU.
Sandor,
The light weight is certainly the biggest plus.
Cheers
Andre

But you don't HAVE to use the built in charge functions, right? You can always just default to your own old fashioned charger, correct? Thanks.

Woketman,
No, you can use your own special charger of course.
Andre

The high-current draw will presumably be for start & shut-down, just for driving the starter motor ?

Now, you cater for an external 12V supply to be hooked up to the GSU -- so if I understand it correctly then even if there are any issues at all with the high current draw at start & cool-down, then anyone who absolutely wants to use the Duralites to save weight could presumably work any such problem by using the GSU with a small 12V pack for all starts & cool-downs (you could probably even just mount the GSU on a small box containing a suitable external nicad pack).

Gordon

The high current draw of a starter motor is not going to hurt the Duralite Plus batteries at all. It's just too short of a duration to be an issue. What kind of max draw are you guys seeing on the KS during a startup?

Gordon,
The TCU sends a "BOOST" command to the GSU everytime it turns on the starter. A constant current of 3A is injected into the system (can be set to max 5A). As long as the Duralites are not forced into a overvoltage condition it should be OK. In our quest to reduce installed weight we designed the system for 4 cells which require very high current to supply the required watts. In the case of Li-Ion the voltage is a lot higher so some reduction in current may be seen.
Doug,
Typically 20A at first turn to about 8 A at 10K with 4 cells. Once the engine fires and spools up this drops right down to 2 A.
Once again I do not have any exposure to Li-Ion so it may be the scenario described above is quire feasible.
Andre
MD BMT