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Post by flydiver on Dec 17, 2008 23:17:13 GMT 1
NOT the balancing port. You're just charging a battery> + to +, - to -. The only reason you can't do this with your lipo charger is the manufacturers with GOOD cause have made it so you CANNOT charge a battery that has gotten TOO discharged. They don't want to be sued. For anyone that blithely thinks the liipo danger thing is not a real concern I think you should take a look at this: Careful! - Lipo Fires Are Real!!!! www.rcgroups.com/forums/showthread.php?t=719116IMO the 9v battery doesn't make a bit of difference. You just have to get enough juice in there for the lipo to be recognized by the charger. For all you folks following this the FMA Cellpro 4S DOES have a function for recovering batteries that have been discharged below 3v/cell. It is NOT a miracle, and will NOT FIX THE DAMAGE. If the battery is too low it won't work at all. In all likelihood it would not work in this case. It charges/balances at a VERY LOW RATE until the battery is back up to snuff. Easy and effective charging safes are an inverted old clay flower pot, crock pot, steel pot, etc. Prop the edge up so the wire can get out. Put a brick on top if you like. |
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Post by mrmugen on Dec 18, 2008 0:09:42 GMT 1
The current charger I use for trying this is the MKII by hobbico. I use it on lipo setting if it will let me. If not I use NiCd setting and use a voltmeter until the pack reaches over 9.6v.....it loses some on the way to the next charger. I do not recommend this to anyone but it is your own choice to try and do so. Because I did it without incident does not mean you will. Just thought I would say so.
Kevin
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Post by bucknut on Dec 18, 2008 18:40:01 GMT 1
I tried the 9v battery connected to my LiPo and it gave it enough voltage that my Elecrifly Equinox balancer at least acknowledged it was there and even balanced the pack.
The problem is when I hook the Equinox balancer to my Dynamite LiPo charger so they interface, the Dynamite charger lets out this obnoxious warning beep and it won't charge the LiPo. I'm assuming the balancer is fine with 3.0v per cell, but the charger needs a higher voltage before it will engage the charging cycle.
I'm guessing, based on some other threads, that I need to get my 11.1v pack to at least 9.6v. Only way to do that is to hook it up to a NIXX charger and monitor. BTW, the LiPo pack didn't puff or get warm while hooked up to the 9v battery. I had them connected for about 20 minutes with no interuption.
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Post by flydiver on Dec 18, 2008 19:10:20 GMT 1
BTW, the LiPo pack didn't puff or get warm while hooked up to the 9v battery. I had them connected for about 20 minutes with no interuption. In terms of mA there is almost no juice in a 9v battery at all. You could use a car battery  . There's some juice in there!!!! Kidding, don't do that. Use the NiXX charger on the low setting. Monitor and leave it on for as short a time as possible. A discharged lipo is not dangerous (it's an empty firecracker). With 9v worth of juice in it it's about as dangerous as a 9v battery-pathetic. You aren't in any REAL danger until you get some REAL juice in it. That's when it's armed. Once you get the lipo charger to accept it and start charging, THEN you need to watch it. Charge it SLOWLY, SLOWLY, SLOWLY. |
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Post by bucknut on Dec 19, 2008 1:38:39 GMT 1
As of right now, 7:30PM EST, my once thought dead LiPo pack is taking a charge ;D I ended up bypassing my balancer and went straight from the output jacks on my Dynamite LiPo Charger directly to the dean's connector on the LiPo pack for about 10 seconds. Then I immediately plugged the Equinox balancer into the port and then back to the charger and pressed the magical button. IT IS WORKING!!!! It's charging right now at 1.5A and I'm constantly monitoring the pack. Not warm and no puffing. When watching the balancer working it seems cells 1 and 3 are getting most of the attention, but it appears to be working fine. I will mark this pack with a Sharpie and see how it performs as compared to the other pack. I want to give a big "shout out" for everyone who gave me advice. I was so close to pitching this pack, but as I've seen "Cubbers" don't give up. Gotta love it!!!! Thanks again......  |
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Post by flydiver on Dec 19, 2008 20:32:55 GMT 1
Probably too late but I would have used more like 0.5 or even 0.25A for this charge.
Please let us know how it charges, now it hold up next flight, and more importantly, how it is about 10-20 flights from now.
Hope it works out.
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Post by patmatgal on Dec 20, 2008 0:12:39 GMT 1
bucknut
Glad you got it charging, hope things work out for you. Got a little ( OK, a lot) fed up with the stock chargers and plunked down the $ for a Dynamite AC/DC Li-Po charger. So far I balance the batteries every third charge with a stock balance charger. When the stock balance chargers goes South I'll get a balancer to use with the Dynamite. Am curious as to which one you're using (don't need all the bells and whistles, just something to put the juice where it belongs).
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Post by bucknut on Dec 20, 2008 4:47:55 GMT 1
My Dynamite AC/DC LiPo charger is left over from the days when I ran brushless RC trucks. I just recently added a Eletricfly Equinox that I got off of eBay. I think it was like $30 and it's tiny. It balances by itself using the power from your lipo or you can use it in "interface" mode and it balances and charges at the same time using the Dynamite Charger for the power. It's super simple and cheap.....I love it. BTW...if you ever over discharge your lipos the Dynamite charger needs to see 9v in you lipo or it will give you a warning sound like a flippin' siren.....no kidding....LOL!!! My dog was howling |
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Post by patmatgal on Feb 12, 2009 21:55:59 GMT 1
Uhh..
Found my way back to this page 'cause I would really like some opinions. Long story short: Landed my Cub in a tree on Jan 12th and recovered it today, Feb 12th. 1 month in the tree and the brand new Rhino 1750 is deader 'n a door nail. Brought it home and hooked a voltage meter to the balancing tap, an Art Tech direct charger to the Deans discharge connection, this brought it from no reading to 9.1 volts in about 45 seconds. Now I've put it on a Cellpro4 and and it's being balance charged, first on the "Low Voltage Recovery" at 1 Amp and then it switched over to "Safety Charge" at .5 Amp when the pack reached 50% (I'm thinking it'll finish charging at .5 Amp) The whole thing is in a Crock Pot next to my stove in case things go bad but so far it's all looking good, no puffing or battery getting warm. I plan on taking the battery off the charger when it reaches 90% charged and doing that for the next several charges. I'm wondering if the reason things seem to be going well is because the battery was new (first flight landed in the tree) and keep a sharp eye on it from now on or maybe I should just hook it up to a light, drain it, dispose of it and chalk it all up to experience. I figured the battery was a gonner after 1 week and am OK with losing it, I'm trying this more for the experience than anything. Hopefully I put all the pertinent info in here and would appreciate what anyone has to say, good idea, bad idea, indifferent, salvage it, trash it, any 2 cent please.
Thanks much
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Post by flydiver on Feb 13, 2009 0:26:29 GMT 1
This kind of situation get opinions ALL over the map-from go for it! to, jeez man, want to burn your house down?! Get rid of it!!!
A dead lipo is of no particular danger-it's a pile of relatively inert chemicals. A charged (charging) lipo or crashed/charged lipo are the danger.
If you are personally comfortable with it you can experiment. You are already being careful so that's good. Continue to do so. Do no relax precautions on that battery.
Likely having been that discharged for that long the battery has taken permanent harm. How much, you'll have to find out by trying it. It will NOT hurt it to 'under charge'-in fact it's actually easier on the battery. You can stop at 90% and try flying that. Try to avoid going below 20% remaining ever again.
If it just sags and wont' do decent power at all it's shot. Discharge completely and discard. If if works, use it, but monitor closely. Keep us posted. I'm curious how these things turn out in the long run.
I've puffed on battery by leaving it in a plane. No recovery available.
A buddy broke tap wires on some Loong Max's. Cheap/stupid charger just charged them as 2S, but flying pulled energy out of all cells so 1 cell got really drained. A Cellpro would have caught that. Fixed the tap, used my Cellpro to recover the battery and it seemed OK but only lasted 2 months and that overdrawn cell went bad. Not sure if a newer cell will be more resilient.
Bucknut - How is your battery holding up?
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Post by patmatgal on Feb 13, 2009 1:52:28 GMT 1
Thank for the input
After charging it I did compare it against an identical Rhino 1750 that has only been recharged 2 times. The sides of the suspect battery were a little swollen & mushy so I'll just drain it and dispose of it. It was probably an exercise in futility but not a total loss, learned something. Oh well, now to find that ligh bulb...
Thanks Much
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Post by ginginho on Feb 13, 2009 13:47:30 GMT 1
... A buddy broke tap wires on some Loong Max's. Cheap/stupid charger just charged them as 2S, but flying pulled energy out of all cells so 1 cell got really drained. A Cellpro would have caught that. Fixed the tap, used my Cellpro to recover the battery and it seemed OK but only lasted 2 months and that overdrawn cell went bad. Not sure if a newer cell will be more resilient. Bucknut - How is your battery holding up? On the subject of LoongMax's and the balance leads, I've snapped one off on one of mine. It seems that the solder of the balance leads is a weak point on these, a mate has done the same. I was lucky it was the earth so I soldered it to the main earth and all is OK. Something for anyone who owns Loongmax's to be aware of. Apologies for the detour of the thread.... |
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Post by flydiver on Feb 13, 2009 19:15:17 GMT 1
It's not the solder, it's the wire. Puny wire. Best to fix the wire with some tape of hot glue so the end doesn't get flexed/worked.
I opened up a pack to solder, finished that, and another wire broke off while I was putting it back together. Known Loong Max problem.
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. There's some juice in there!!!!
