Banche

I have 3 new TBM batteries for my TOC yak. They are 2 cell 2800mah 8.4 volt.

They came to me halding 7.5 volts and I stuck one on the charger for 15 minutes and then took it off and tested the voltage.

IT READ 7.4 and was only kinda warm, just barely to the touch.

Then I stuck it back on for another 15 and took it off and it READ 7.3.

I though, is my charger busted, it is the wattage charge it all sport. It's supposed to charge everything nimh nich lipo and li-ion.

I know it works, atleast for nimh because I charge batteries on there for other planes all the time.

Here is the funny think. I tested the battery and put a 1 amp load on it and it read back up to 7.5 then it dropped back down to 7.3volts.

The other batteries read 7.5 and when I put a 1amp load on them they read 7.2 or maybe .1 or .3.

Whats the deal. I am new to li-ion's and need help! I can either charge them at 1.3 amp or .7 amp.

Which is better? How can I charge these corectly or are they bad? Please help. I no the answere is probably easy but I have looked everywhere!

Rockyaged

My first question is, is your charger made for charging Li-ons.
There is a difference. Chargers built for Nicads or Nickelmetal
battery packs will not charge Li-on. There is a difference in the
Chemistry buildup of the batteries. If you don't know, you will
need regulators to regulate the battery's voltage down to a max
of 6 volts. Always use the 1 Amp load voltage reading and DO NOT
fly when the voltage is 7.0 volts or less.
I might also suggest you spend some time in one of the Electronics
forums to bring your knowledge of different batteries up to date.
Hopefully, you did not hook up the batteries to the receiver before
using regulator. If you did, it's likely to need to go back to a repair
station to be checked out. If it seems to work okay with proper
connections, regulators, be sure to do a good range check.
Lastly, when you get the plane to the flying field, find some with the
right knowledge to check what you have done to be totally safe.

Gerald

IFLY3W

My Feedback: (5)

Ok, first things first. He says that his charger is rated for lipoly. That is ok! The batteries should not be getting warm at all, even charging at 1.3A. He is charging up 2800's. It will take over 2.5 hours to fully charge them, if they were at 6VDC. I think that if they were getting warm, you could have been charging them on the wrong type of battery?? Only speculation.

My only real concern is, what is the procedure to change the charger from NiMH to Lipoly?? Do you push a button, move a switch?? I'm not at all familiar with your charger. Also, what type of voltmeter do you have??

Me personally, I have LOTS of expierence in Lipoly, I deal with them on a daily basis. I would tend to think that I am somewhat Lipoly knowledgable. If it were me, I would keep that charger for strictly NiMH's, and buy a Lipo charger only. FromeCo makes a REALLY nice unit, that you can upgrade to as many as 5 charge ports. Comes std with 3. Charges at .5A or 2A. 2A is great for your 2800's. Senses when the pack is getting full, and ges from a C-C(constant current) charge to a C-V(constant voltage) charge, while tapering the current down. Or see what Gene recomends at TBM for charging Lipo.

Any more questions, feel free to ask!!

Chris~

ShawnM

My Feedback: (6)

I agree...make sure your charger is acceptable for these batteries. If you can tell us what charger you are using that would help.
If you are reading 7.2 or whatever volts then your batteries are good. If you had lost a cell your voltage would be around 3.6v, so as it is your batteries are just fine.

If you have the correct charger then just let them charge until they are finished. It is better to use the lower current setting unless you are in a hurry for some reason. It will just help to extend the life of your batteries by charging them a little slower, but if you're at the field and want to use the 1.3a charge rate then that would be fine too.

After they are fully charged you should see around 8.1volts with no load. With a 1amp load my batteries typically read 7.7volts. (they are TBM 2800's like yours)

Make sure you install them....battery--switch--regulator--reciever. You can't charge them going back through the regulator.

I hope this helps some.

Diablo-RCU

My Feedback: (1)

Before you put your batteries on charge, call your agent and double your homeowner's insurance. Sounds like Dave Brown might be writing a column about you soon...

Serioursly, before you use any charger with Li-X batteries, you better know EXACTLY how your charger works and the voltage and current it puts out over a charge, and how it terminates a charge. Otherwise, very bad things will happen.

ShawnM

My Feedback: (6)

I missed the part about your batteries getting warm. I agree with IFLY3W, they shouldn't be. I use a Triton and a Powerflite charger and my batteries stay cool. You can't even tell they are being charged. Get the manual out on that charger and see what it says and let us know what it is. Lots of folks here are willing to help

Banche

Well my batteries didnt get warm. Just room temp I was imganining things.

Alot of u missunderstood.

I said I got a li-ion charger. My batteries are li-ion no li-po so they should charge at 1 amp I think for the best results.

My voltage tester is the hangar 9 one that can use .5 1 and 2 amp loads. My charger and volt tester both work fine because they have charged and tested li-pos on many ocasions and

IFLY3W

My Feedback: (5)

Ion and Poly charge the same way. You can safely charge your Ions at 2.8A. But like you said, slower is better for charging. Just takes a bit longer..

I guess some of your info was unclear to most of us, so we all went to the extremes to keep fellow modelers safe with Lipo. I use Lipo in my GS airplanes. Do I fear them, you bet!! Do I charge them as fast as I can, you bet I do!!!

Room temp is fine. Just be certain as to how you set your charger from NiMH to Lipo, make sure that it is on the right setting, and everything will be a-ok!!! Any warmer than room temp, or ambient temp, might want to check things out...

I charged my Lithium's in my GS'er on a Orbit PocketLader until I got my FromeCo charger. Now I can do all 4 of my packs in my GS'er at 1 time!! No more waiting on the charger to finish, so I can charge the next pack!!

Enjoy!!

Chris~

Rockyaged

Blanche..

Could you tell me the brand name of your charger
and it's model number. I do not know of any charger
that will charge Nicad, Nickelmetal and Li-Ons/Li-polys.
I would like to research that charger.. thanks..

Gerald

naamanf

My Feedback: (3)

There are a lot of chargers that will charge all three types of batteries and some that will even do lead batteries. I own three myself that will do all three. Triton/Hobbico Elite/ Hobbico Mk II.

jjamesrb

My Feedback: (39)

I had the same problem charging the TBM batteries, you have to use a duralite charger that TBM sells.It will charge 4 at the same time.I tried a couple different chargers that charge li-ion and they wouldn't charge them.Call Gene up at TBM and he can help and make sure you don't charge the batteries incorrectly because they will catch on fire and explode.