Lithium polymer testing
 

Just received the FMA/Kokam Lipo 402 and am now comparing it with the Hobbico Quick Field Charger MK II, Triton and MAHA MH-C777+ as to performance on Kokam cells.

I have focused on the KOK 2020 simply because that is what I happen to have the most of.

3 cells, A, B and C are compared. I discovered my Victor Engineering Super HiQ is still a wonderful piece of equipment, capable of charge and discharge very nicely of Lithium cells since you can program exactly voltage cut off points, voltage limits on charge as well as max current and cut off current levels. I am using it mostly as a discharge device set at 1 amp discharge to 3 volts/cell.

Chargers are Identified as T= Triton, K= Kokam, and Q = Quick Field Charger Mk II, V= Victor Engineering, M= MAHA MH-C777 Plus

All discharges are with the Victor Engineering unit except where noted. Some discharges were done with Alpha 4 on C function (low capacity set so it could be disconnected before overcharging)

All charges set at 1 amp.

A charge w/M input 3123 discharge 2335
A charge w/T input 1945 discharge 1930
A charge w/V input 1978 discharge 1990
A charge w/V input 1982 discharge 1983
A charge w/T input 2002 discharge 2003
A charge w/K discharge 2107

B charge w/Q discharge 1757
B charge w/Q discharge 1749
B charge w/Q discharge 1767
B charge w/M input 3151 discharge 2543 (Alpha 4)
B charge w/Q discharge 1754
B charge w/Q discharge 1765

C charge w/? input? discharge 2351
C charge w/T input 2079 discharge 2312 (Alpha 4)
C charge w/ input 2071 discharge 2063
C charge w/Q discharge 1750
C charge w/K discharge 2067
AB charge w/Q (in process)

Some discrepancies but I think we can see a trend here. Remember, it is much easier to nit-pic the data than it is to gather it or explain it. :D

Stay tuned!

Lithium polymer testing
 

wow! talk about confusing lo

Lithium polymer testing
 

Interesting Data Red,

I am thinking of purchasing a Triton. Do you think it's wise to wait and see if GP will change/upgrade Lithium software on the Triton or do you think it's satisfactory as it is now?

Thanks

Mike

Lithium polymer testing
 

I think the Triton is doing a pretty good job from the data I have collected. You may be able to get a little better service life from the lithium packs using it vs. chargers that may be more aggressive (have not seen any yet other than the MAHA CH777) also we are seeing that the level of charge achievable seems to be charge rate dependent to some degree. The "softer" you charge them the more capacity you can pack it. It figures when you think about it.

Lithium polymer testing
 

Thank you for the quick reply Red

It makes sense that a slower charge rate increases charge level achievable in the pack.

Do you know if some of the German chargers such as the Orbit or the Schulz(sp?) do better or worse job charging/discharging Lithium packs?

Thanks

Mike

Lithium polymer testing
 

Sorry, I don't have a clue - they never submitted a sample for testing. :rolleyes:

Lithium polymer testing
 

Hello guys,

I just bought Hecells Lipo 1400mAh, it doesn't have neg./pos. indicator. I was just wondering. How can I determine neg. and pos.? And how to configure these cells? (+ to + and - to -)

Thanks
genovia

Lithium polymer testing
 

You can use a digital voltmeter to determine polarity. When the voltmeter reads a positive voltage the positive terminal is the one connected to the red probe.

Poly Lithium??
 

Hey Redscho,

I'm kinda new to the electrics, but I'd like
to get one of the IFO MK3's by WildRC.

Some of the guys at the flying field have
one and it looks like a blast.. but they can't seem to agree on the motor/gearbox and the batter/charger setup. From what I've read wildRc reccomends the graupner
280 with the 4:1 gearbox, as well as the
3-cell poly-lithium batter and charger. However I've read a few articles on rcuniverse of guys who use the 2-cell setup and seem to have plenty of power to hover and climb vertical with flight times of 20 minutes or more..

You sound like you have some experience with batteries/chargers so
Any input would be greatly appreciated..

flyguy77..

Lithium polymer testing
 

Have no experience with the plane you mention. I am flying lithium polymer in place of 7 cell Cs Ni-Cd 1700 using 2s2p 3300 packs. Not quite the punch of the Cs but awsome fight time. Also using 2s 1020 lithium polymer in place of 7 Ni-Cd 150 mAh - on a lite stick and in a GWS Tiger Moth. No apprecialble change in performance except for extended flight time of 30 minutes. Charging with KOKAM 402 or Apache 1200 or Triton.

Lithium polymer testing
 

Red does know his batteys take a look at
resume he helped devlope the nicad and more. CU

RE: Lithium polymer testing
 

Red, if I am understanding correctly, the batteries had better capacity with the Maha charger. Looks like the battery charged with Maha had the largest discharge reading.
Did I understand correctly?

Thanks for the expertise.

RE: Lithium polymer testing
 

That is what the testing showed on that particular set of cells 6 months ago. The MAHA has since been pulled from the market by FMA due to some risk in charging Lithium batteries. I have found that the Triton does an acceptable job and doesn't push the envelope as did the MAHA.

RE: Poly Lithium??
 

What ESC are you using for the lithium set up in the Tiger Moth? I'm looking at moving in this direction with my moth.
thanks.

RE: Poly Lithium??
 

What ESC are you using for the lithium set up in the Tiger Moth? I'm looking at moving in this direction with my moth.
thanks.

RE: Poly Lithium??
 

I'm running a Jeti 05 (I think) with 2S1P 1100 mAh pack (FMA-Kokam).

RE: Orbit V6.2 for lithium-ion
 

Update: 11/10/03
I have since received an Orbit V6.2 for testing. So far it looks like one great unit. Looking at lithium pack charging and it seems to be doing great in this area as well as the standard Ni-MH, Ni-Cd and Pb packs.:D

RE: Orbit V6.2 for lithium-ion
 

You can purchase the Maha charger 777plus here:
http://www.mahaenergy.com/store/view...?idproduct=185

cost: 89.96$

Scou

RE: Orbit V6.2 for lithium-ion
 

Red, can you give me more details on your numbers above please? I dont understand what do you mean with all these numbers? What is good and bad results from your tests?
Scou

RE: Orbit V6.2 for lithium-ion
 

The charges were all at 1 amp. Number after input is the mAh of charge that went into the cell, the next number after discharge is the capacity yield in mAh. The code for the various chargers is given in the opening thread.

RE: Orbit V6.2 for lithium-ion
 

Thanks Red, it's more clear for me now.

The triton and the Victor charger seem to be the most accurate to charge lithium pack and Maha seems very agressive?

I am looking for multi-fonction charger to cycle my Nicad pack and i will try the Triton because i will put the Duralite lithium pack in next gas plane. I hope being more lucky than the guy in RCU who is at the 3rd defect Triton? There are many people having problem with the Triton but my feeling is, if you read the instruction and don't do stupid things, it should be a great charger
Scou

RE: Orbit V6.2 for lithium-ion
 

Then if you are going to use Duralite, then get their charger. This will avoid a p***ing contest when you have a problem with the battery.

RE: Orbit V6.2 for lithium-ion
 

For the price, this Maha charger looks to be a great deal.
http://www.mahaenergy.com/store/view...?idproduct=185 (thanks for the link)
Are there any known problems with this charger? I am on a bit of a budget now that my brushless heli is almost complete and was seriously considering this charger. What say you mang?
Thanks
Barry

RE: Orbit V6.2 for lithium-ion
 

Yes, they were pulled from the market by FMA.

"The management of FMA, Inc. has recently determined the product formally distributed
by FMA Direct as the MAHA777 to be unsafe for charging certain battery types. If you
currently own a MAHA charger, do not under any circumstances, leave this charger
unattended while charging Lithium Ion or Lithium Polymer batteries. We have recently
found that the MAHA777 Plus charger is not reliable in automatically detecting the
correct number of cells in a lithium battery pack. The proper selection of cell count in a
lithium battery pack is crucial to the safe charging and termination of charging. The
result of improper selection of cell count has led to over-heating of the lithium cells on at
least two occasions. FMA, Inc. will be issuing a formal recall on this unit to all
customers who are known to have purchased the MAHA777 charger directly from FMA
Direct. Please watch for this recall notice in the mail. If you have purchased a MAHA
charger distributed either directly from FMA Direct or from a local FMA Direct dealer
and you are affected by this recall, provisions for returning this unit will be included as a
part of the recall letter. We apologize for the inconvenience. We at FMA, Inc. are
greatly concerned about this unfortunate problem and we are taking every action in our
power to remedy the situation."

RE: Orbit V6.2 for lithium-ion
 

okay back to the triton then