i3dm

My Feedback: (51)

Hello guys,

Will my Fromeco 5200mAh Li-ion pack be able to stand to the current load of a Jetcat ECU with Kero plug driving my P-70 ?
I can tell you this pack does run great on the GAS version Jetcats.. P-60 to P-120 been tested flawlessly.

thanks.

SinCityJets

I don't think the li-ions have the poop for the kero start.

Chad

Greg Wright

My Feedback: (6)

If it was myself i'd stick with a NIMH i had a 4600mh r/c car pack on a p-80 and the kero start plug and could get six to seven succesful starts & flights with that set up.

SinCityJets

3 cell A123 (with ECU upgrade)

jonesmarvin

My Feedback: (10)

It is working for me on three JetCats!
Marvin

i3dm

My Feedback: (51)

What is ? Li-Ion and Kero start ?

Guys, does anyone know the current draw of the Kero plug during start up ?

digitech

My Feedback: (10)

30 amps for about 2 seconds
then goes down to 10 amps

all my jetcats do at least 3 starts on a hobby city lipo 20C 2200mAh 7,4 volts.
and that is a 12 usd battery

i3dm

My Feedback: (51)

Sandor,

thanks for your reply. i know a Li-po is the easy way to do this and i love Li-pos, but in this plane the battery is in the nose, and its impossible to pull it out during charging, and i will never risk charging it in the plane. (even balanced).

An A123 upgrade might be in order, but that requires a round trip abroad for the ECU. just trying to find the easy way out of this..
PS - i sent you an email asking for a shipping quote on your Kero plug.

Im still curious if anyone tried this with a large Li-ion like the Relion 5200mAh.

jonesmarvin

My Feedback: (10)

A123 and kero start.

David Gladwin

On my P70 with kero start I plug in a booster battery for the start sequence to augment the standard Duralite ECU battery. I use either a Duralite Lith. Mang. battery or a standard Jetcat 7.4 nicad, the former is better the latter helps get about 5 starts from the standard Duralite ECU battery. The battery can be any size, bigger is better and lipo, li-on, or even Nicad seem to work so long as the voltage is around 8v. (6 cell Nicad or two cell lithium.) A123s works great with JetCats BUT you need to get the ECU modded or the ECU may fail at any time (or may not, I had 2 fail, one was fine !)

Using the booster method also means that you dont need a large ECU battery in flight.

I simply arranged a Y in the power lead to the ECU.

Without the booster I was getting only one reliable start.

Regards, David Gladwin.

Gonzalo38

David:

Do you have pictures of your install ? I'm planning to use a Fromeco Li-on 5200 mah battery.....

i3dm

My Feedback: (51)

Same here - and shouldnt i be worried with using 2 packs for startup in parallel which are not matched in voltage ?
Also David, when you say you got just one good start - is that on a Fromeco 5200 ?

David Gladwin

My BobCat with a P70 has aways flown with a Duralite ECU battery (2500Mah ish) Got upto 10 flights without recharge.

Swapping to Kero start I got one, perhaps two, starts then recharge was neccessary.

I then connected a second, booster, battery by creating a Y-lead in the cable to the ECU with a male Multiplex connector. Before start I then plugged in a Duralite 3000 MAh lithium manganese battery. Got lots of consecutive starts without trouble, disconnected this batt. after start complete.

I needed the LiMang for an airborne installation which needed nose weight so tried a spare JetCat Nicad as a booster, works fine !!

If you watching the battery voltage during start without the booster it drops almost to empty, connect a lith mang, ( a 2s lipo would work just as well) very little drop. With the nicad, it does drop but not as far as with the ECU battery alone. As the voltage on the Duralite drops, it will fall below the value of the Nicad which then shares the load, thus the voltage doesn't drop so far. result : several trouble free starts. Trust me, it works !!

Not sure why you need a picture of my installation, all you need is to make a y-lead in the cable from ECU battery to ECU, thats it !

Regards, David.

ColinW

JC 160 kerostart. Thunder Power 2S 4200 Mah 15C - 4 starts and 15 minutes running needed a recharge of 990 mah

i3dm

My Feedback: (51)

I hear that A duralite Li-ion cant take the load but a Fromeco Li-ion can and will work with a Kero-start. i have been told it was tested.

Gary Szetlak

My Feedback: (13)

these are the specs on the Fromeco Li-Ions form the TBM website

5200 mah 12 amps continuous 18 amps burst
7.4v 6.6 oz

Even if you do get through the start sequence you may be killing the batteries prematurely by pulling the high current. I used the Fromeco Li-Ions for a while and then started getting ECU shutdowns due to low battery. Jetcat seems to be sending Li-Pos with new engines, there must be a reason. Good luck with whatever you choose.

Gary

i3dm

My Feedback: (51)

Gary,

Can you confirm under what circumstances you got low battery shut downs ?
with which pack ? turbine ? after how many starts ? kero start ?

would like to analyze the situation.

Gary Szetlak

My Feedback: (13)

I was using a 5200mah battery, the turbine was a standard P120 NO kero start. I had been using this setup for maybe 15 flights. The first flight of the day the turbine quit in flight. I landed and the GSU indicated shutdown due to low battery. Checking volts with a 2amp load showed the battery to be charged. I put the battery on charge and it did not require much time. So up she went for another flight, sure enough engine quit. Landed, same shutdown message. I was at an event at the time and went to one of the vendors on site and bought a 2400mah 6 cell Nicd. Changed the connector charged it and flew 3 more flights that day no problem. The ECU was probably a 5.0 but I'm not sure. Since then I used Nicads where I needed the weight and lipos when I didn't. I used the Li-ion as a receiver battery in another plane for a long time (it might still be in there) but I have never used LI-Ions for ecu again. But that could have been an issue with my starter motor or fuel pump or whatever. The thing I would be concerned with is that the Fromeco has a burst rating of 18amps, and I believe someone posted a much higher current draw for the Kerostart jetcat. In the end its up to you but I would follow Jetcats recomendation. Good luck.
Gary

i3dm

My Feedback: (51)

Gary,

My friends fly P60s to P-120s on a Fromeco 5200 Li-ion with great success.
Maybe your battery was bad or something.

I ordered the Kero plug - will give it a try anyway and see how it goes.

digitech

My Feedback: (10)

guys believe me

we get 4 starts and flight out of a small 2200 max lipo 20C (jetcat)
all the story,s i am hearing must be a problem somewhere.

1 . dont use a switch between batt and ecu (switches mostly cause restriction due to the small smd copper connections-like going from 3mm to 0.9 and back to 3mm again)
2. make sure you use thick cables.
3. keep them cable.s short! modern battery,s weigh about 290 grams , better mount them close to CG

the keroplugs v3 use only 10 amps , ask any slowflyer how much this is..

best battery,s to use are any lipo,s or A123 with at least 20C where 30C continue discharge holds best.

i3dm

My Feedback: (51)

Sandor,

For 10A you dont need 20C or 30C lipo.

Did you send my plug ?

i3dm

My Feedback: (51)

Here is what i got from Kurt at Fromeco directly:
-
We have several customers that are currently using Relions on Kero Start units. Fromeco has not physically tested this our selves however the Pilots that who do use it are Reliable sources of information. The testing that was done with Kero Start units was done a couple of years ago, if the Kero Start unit has changed since this time frame I can't attest as to whether it will still work or not.
-

derrickxp8103

My Feedback: (80)

A123 Batteries are perfect !!.....no fires no worries, charge in the aircraft . Need to send ECU to JetCat for the mod. I talked to Bob at Jet Cat and they change a couple of diodes and put a Heat sink in the ECU to use A123's.

I also run a Fromeco AMP meter between the bat and ECU......awesome set-up.

I use the new FMA Cell Pro 10 - Awesome Charger and very easy to use.....

A123 Batteries are the future. I am new to them but so far I am impressed and sold on A123's

Everything I have I will convert to A123 except the JR12X transmitter.

i3dm

My Feedback: (51)

Here is Kurt Cook's (of Fromeco Scale Avionics LLC) reply:
-
We have several customers that are currently using Relions on Kero Start units. Fromeco has not physically tested this our selves however the Pilots that who do use it are Reliable sources of information. The testing that was done with Kero Start units was done a couple of years ago, if the Kero Start unit has changed since this time frame I can't attest as to whether it will still work or not.
-

With that being said, i hear the V3 Jetcat unit draws way less current than former versions. but ill test my own unit soon enough (i got it installed already) so i will have real world personal results to post.

i3dm

My Feedback: (51)

Here is some real world test results.

4 flawless starts yesterday, using a watt meter to check currents.

In the pre heat stage the current jumped to about 15-16A for a split second (which got the Fromeco 5200 Relion battery down to about 7.0-6.9V) and immidiately after that came down to about 2-3A or so and the starts were smooth.

4 starts followed by short runs and cool down took out about 500mAh of the pack.

Bottom line: A Fromeco Relion 5200mAh pack handles the Jetcat Kero Start easily.