Li-po voltage too low????

[Tailwind]

Hi All,
I have 2 batteries, a 11.1 900mah pack and a 11.1 650mah pack that my charger is telling me the voltage is too low to charge. The 650 is at 7.3 volts and the 900 is at 5.4 volts. Is there a way to get these to charge without burning down the house? the 900 pack seems a little puffed out? I just totalled my BME edge this morning and I don't want to finish the day off with burning down the house!!

Thank,
Dom

[Colonel Klank]

Dom:

I would like to know the answer too.

I have two new packs and one will charge and the other will not. I have tried two different chargers too. Good luck!

Patrick

[Jaybird]

I'm afraid they are toast. I ruined 2 packs earlier this year from low voltage. I forgot and left them plugged into the charger for about a week with the charger off. I guess the internals of the charger drew them down. I took them out in the back yard and shot them with a 22 hoping to see a fire. They didn't even smoke .
Brian

[Kiwi]

If the pack looks puffy take it outside and put it some place were if it goes on fire it wont matter. The BBQ is great place. Those packs can and do degenerate over time and even though you think they are dead they can still spontaenously (spelling??) burst into flames.

As for the 5.4 volts taking a new charge, well if that pack is not puffed up it may be recoverable. What you need is a good charger and set it on the highest charge rate possible for your cell count. 5 amps is great. Dont worry your not going to charge it with that, your going to kick it to get the cell voltage above six volts. Even if it will hold that six volts for a minute it will be enough for your normal charger to pick it up and hopefully get your pack back.

What I have done is put the low volt pack on the charger and hit the power or start button. Most chargers give the cell a hit then turn off the charge to see what cell voltage you have. When that happens, unplug everything and do it again. It can take half a dozen hits to get that residual cell voltage up above 6. Once you have that your on the way.

You may not ever get a full recovery but in some cases you do. Its the luck of the draw.

I have another method but its dangerous as all buggery. If your charger wont kick the cells up use a standard NiCd charger set at 5 cells and give it 30 second bursts until you get the magic six volts you want.

NOTE!!!!!. If the pack starts to look puffy, unplug it, throw it outside where it cant burn the house down and leave it. Its junk.

Kiwi

[Kuba]

I'm afraid, that lower than 2,8V per cell is a dead end... for 11,1v pack 9V means "discharged". 5,4V means, that You have 1,8v per cell (if they are balanced). That voltage is lower than critical I'm afraid. Have U tried using an ordinary charger in which U can manually select cell number? try charging it like a 2 cell pack

[Tailwind]

Hi guy's
Thanks for all the info, I decided to get rid of the two batteries and not mess with them. I store all my models in one room and I thought it would be stupid to risk my 35% Edge, 27% Extra, misc wrecks, and house for that matter over $60.00 worth of batteries!!
Thanks again for the replies,
Dom

[Vic3D]

	Quote: Originally Posted by Tailwind
	Hi All, I have 2 batteries, a 11.1 900mah pack and a 11.1 650mah pack that my charger is telling me the voltage is too low to charge. The 650 is at 7.3 volts and the 900 is at 5.4 volts. Is there a way to get these to charge without burning down the house? the 900 pack seems a little puffed out? I just totalled my BME edge this morning and I don't want to finish the day off with burning down the house!! Thank, Dom

Sounds like they went south. Did you leave a switch on, or are they connected directly to a regulator??

[Tailwind]

Vic,
One was just sitting uncharged (I probably ran it down to just about where it wouldn't fly the airplane anymore, its been sitting for 6 months), the other I left plugged in on my shockflyer for about 4 hours...won't do either again!
Dom

[Matchless]

You did the right thing by pitchin them....... I know of Kiwi's method, and have used it before as well, but I would not suggest it to anyone! A second of misattention leads to certain problems.

FWIW, I bought myself a 'battery bunker' the other day (google it and you'll find it). The thing is nicely made and I feel it adds just a little more safety to my charging activities...... Piece of mind and Peace of mind for about 30 bucks.

[Benji]

	Quote: Originally Posted by Jaybird
	I'm afraid they are toast. I ruined 2 packs earlier this year from low voltage. I forgot and left them plugged into the charger for about a week with the charger off. I guess the internals of the charger drew them down. I took them out in the back yard and shot them with a 22 hoping to see a fire. They didn't even smoke . Brian

Lol nice job man!

[Jaybird]

Thanks, If it's no good anymore, might as well shoot it!

[IanJ]

Hi,

I recently left a 3S LIPO connected overnight and it wouldn't charge due to LOW BATTERY. I measured it at 2.8v total.

I easily ressurected it by charging it with an old Lipo charger I had from ART-TECH.

Ian.