Shockdriver

i have 2 11.1v 1800mah batteries and they have been working fine until now im trying to charge them but the light that says they are charging dosent come on the chargers fine, i can get what litttle power they have left in them out of them i just cant put power back into them.

Any suggestions

lejongleur

My Feedback: (10)

If you have a balancing charger with a cell display you could see if something is wrong with one of the cells (i.e. low voltage), causing the charger to turn off safety reasons. However, as you have two lipos, I suspect that the charger has a problem. You might consider being very careful in using it, as overcharging lipo cells has drastic results.

If you think it is the charger, you can get some fairly functional chargers from hobbycity.com of places like that for around $55. Alternatively, find someone else who has a charger that should work with these batteries, and try that one.

Hope this helps !!

Mr. Mugen

What charger? Balancer?

johnpcunningham

Measure the battery voltage. It it is less than 9 volts or greater than ~12.6, you may have a problem with the batteries. This is common when the charger won't balance or the voltage is too low. Lipos typically have a separate plug - for an 11.1 volt lipo it shoudl have 4 wires. One is ground and the others go to the + of each battery. You should be able to measure each cell individually. If one is below 3.6 volts or the entire pack is less than 9ish, the charger may not activate.

May want to list
1) What type of batteries
2) What charger are you using
3) Have you been balancing the cells

Shockdriver

how can i get enough power into them so the charger registers it to be connected

hugger-4641

My Feedback: (6)

I use a regulated 12v dc power supply with adjustment between 300 to 1000mh to revive weak cells. In the absence of this, you probably have a transformer laying around such as a cordles phone power cord, radio, cell phone charger, etc, that you could use in a pinch. Output needs to be 10 to 14vdc and no more than 1000mh (1amp). Determine polarity and make some kind of leads to connect to charge plug and charge the weak cell for 10 to 15 minutes (keep close check on battery temp) and check voltage. After a couple cycles you should see voltage come up on the weak cell. When you get about 3volts on each cell, the charger should accept it. Be very carefull doing this, don't short anything out, and don't leave unattended. Lipo's can and have caught fire!!!!!

cjg

Are you running the batteries until they are fully depleted? If so, that is probably causing the undervolt problem and can cause permanent battery damage. Don't run them down more than about 75%. Resist the urge to use them to the last bit of flight...

Mr. Mugen

If I were you I would be doing some reading on lipo's. You are playing with fire. Knowing is half the battle.

Kevin

Shockdriver

what do i need to use to connect the leads from the charge to the lipo and how

Mr. Mugen

Any chance you have a pic or can take a pic of your entire battery/charging system? You should have botht he balancing and main leads attached during charging unless you have a charger that only connects to the balance port. Pic?

Kevin

Shockdriver

[img][/img]

Mr. Mugen

OK On the other side of the balancer is there a plug in for charger? If so then you need to make a pigtail with the deans male on one end and the plug for the balancer on the other and charge the battery through the balance port.

Kevin

Shockdriver

but the charger has a green light that comes on when the battery is connected and the light is not coming on

Mr. Mugen

So that little black box is your charger? Who makes it? Looks like a balancer to me. How do you power it? With 12v or 110?

Shockdriver

12v charger that plugs into it

Shockdriver

Its an E-MAX charger
[img][/img]

Mr. Mugen

If you plan to run lipo's for a while I would think about other chargers. That is a poor lipo charger. I am not trying to knock your equipment so please don;t think I am. I am just saying those chargers are not the best for balancing the pack. They start to balance but when the voltage it see's hits the mark it will stop charging without concern to what each cell has in it. One cell may have 4.4v while 2 others only have 4.1. I have done some testing with a charger that is identical and found bad results....and very inconsistant results. If you don;t want to spend a lot of money on a charger I understand but your batteries won't.

Is there any way you can check the pack voltage as a whole? Or better yet check each cells voltage? You may just have a bum charger. It has happened before.

What are you using these packs in? Does the plane/car have an esc with a LVC? If not then you may have depleted the pack too far for the charger to recognize.

Kevin

Shockdriver

there in a T-34 mentor with a 1750kv motor 30A with bec and 4 9 gram servos what have you heard about the Zippy batteries

Mr. Mugen

Do you know the amp draw of the motor? And what is the cell rating of those zippy's? Like 15c, 20c, 25c etc.... If they are 15c they can make 27 amps constant and about 50 burst. This is on the low end of the spektrum. If they are 20c or greater they will be fine. This is assuming the plane needs 25a to fly. Like I said, if you plan to do this for a while a good charger will never hurt. There are lots of choices out there for any budget that will do. If you cannot check your cell voltages then your always in the dark. I assume your esc has a lvc set from factory or you yourself set it up....? If not then you need to do that asap. Never run lipo's below 3 volts per cell. So your lvc should be 3.0 or higher. I like mine set to 3.1 in case I am out a ways when it kicks in. ALways cushioning for more motor if needed.

Kevin

FERNDALE AIR FORCE

Shockdriver, I bought a couple of inexpensive chargers like that. I have since retired them. They were not balancing correctly. I would recommend investing in a better charger. I guess that sounds pretty harsh but if a charger gives you reason to doubt it, junk it. The risks are real. I would recommend getting an astro blinky to see if your cells are balanced or just pin out the cells with a decent dvom.

Here is a link to a really nice charger at a really nice price. The second pic is from the us warehouse so it includes most of the shipping from china. http://www.hobbycity.com/hobbycity/s...wer_Search.asp

Tim

hugger-4641

My Feedback: (6)

A small insulated solid wire would be the safest (20 to 30 gauge) if you had some old phone cable or door bell wire laying around, two different colored wires about 6" long would be ideal. You could also use the center conductor of a piece of TV cable/coax. If niether of these is an option you could straighten out a couple very small paper clips and wrap them in electrical tape. Either way, leave about 1/4" of bare wire on each end to connect to charger and charge plug and tape them up so they can't come loose or short out. Do all this with the charger unplugged from the 110vac!!!!. Be absolutely sure about the polarity of the charger and the cell you are going to charge and make sure you connect them correctly!! And once again, Be carefull, you are playing with fire!!!!

hugger-4641

My Feedback: (6)

My dial up updates so slow, I thought you were responding to my post, MrMugen has you on the right track!!

FERNDALE AIR FORCE

Hugger, that was ....... ok it was.

Shockdriver, I have the accu-cel and use it over my triton jr/equinox system. The c rating of zippy's is easily found. I think they are 20c batteries.

Tim