Question about new Li-Po batteries

[Skyguy]

Hi, everyone. I have some questions about new Li-Po batteries. I have read Bart's excellent treatise on the subject and found it helpful but not specific to what I'm looking for. Of course, they're going to teach me to read next week so I may have missed it. To help clarify, I'm flying a Blade Nano QX whose original 1S batteries are 150mAh 25C and some after market 180mAh 45C batteries.

So with that as a backdrop, here goes.

I have not seen anything specifically targeted at how to "break in" new batteries but someone told me that you have to do so. He said when flying with new single cell batteries you should limit the initial flights to just a minute and a half or so. After recharging, repeat that sequence again three or four flights. Then fly for two minutes several times, then two and a half, then three, and so on. He said the worst thing to do was to fly until the quad signaled it was time to stop. Well, of course, that's what I'd been doing -- flying until the bird says stop. So okay, he might be right, but like I say, I've not seen anything anywhere about this. So is he correct or is it just some misguided attempt at impressing me?

Second, I get the impression that once the charging cycle is complete, you should pull the batteries off the charger immediately. In other words, they shouldn't sit in the charger for five, ten, twenty, thirty or sixty more minutes. This implies Li-Po chargers do not turn off when the cycle is done, but continue to charge until you physically remove the batteries. Frankly, that just doesn't seem quite right to me so maybe I'm misunderstanding it. I may be reading too much into it but I'd really like to know for sure what this is all about.

Finally, what about letting the batteries cool down after a flight and before you charge them? I've also been told that once they're off the charger, they should be allowed to cool down before putting them back into the quad. The same goes for waiting to charge them after they've flown. I have not noticed any warmth at all on my batteries so I have to question if this is a legitimate concern or not. Any thoughts?

If you are knowledgeable in these areas and can address these questions authoritatively, I'd really appreciate your help. If you want further clarification, please feel free to ask. I'd be happy to do so. As you can tell, I need all the help I can get!

Thanks,

Bruce

 

[jbrumberg]

Many "toy" grade RTF 1S LiPo's have overcharge protection circuitry built into the stock battery and/or the stock charger. So leaving the stock battery on the stock charger for a little while while not the greatest is not the worst thing that can happen. It's the aftermarket batteries that usually do not have the OCP circuitry. So one has to be careful charging aftermarket batteries which probably do not have OCP and know whether or not the stock charger has the ocp circuitry. It's still not a good idea to leave batteries connected to a charger for any extended period for safety reasons regardless. I let my LiPo's cool down after use and before charging them and after charging them and using them. I charge with a "smart" charger. I do not use stock chargers.

I do not know anything about breaking in a LiPo battery. I might have broken in my old 1S SYMA S107G's and N's built in 1S LiPo's. Maybe brushed motors need a break in period. Motors definitely benefit from cooling down before re-flying.

You should check your batteries with a multimeter. It's not a good idea to run them down below 3.4V/cell.

I do not consider myself an expert in this, but I have been flying "toy" grades for around a year and I have not destroyed any batteries yet. I have burned out a few motors and broke a few parts though. I hope that this helps.

 

[Scott Drysdale]

Batteries appear to be simple but there is a lot of complexity under the hood with respect to the nature of the electrochemical activity going on inside. And LiPos are the most complex of all battery types such that TLC is required to make them last longer.

WHEN TO LAND YOUR MR: If I recall correctly, the Blade MQX documentation included statements about how to work with these very small batteries. I believe the manual stated to end each flight before the MR requires emergency landing.... or was that the the DJI F550/NAZA manual(s)? Cutting flights short initially helps to breakin the battery chemistry properly to enable the electro-chemistry to remain optimal for longer.

HEAT: Battery electro-chemistry takes a beating when there is excessive heat as when rapidly depleting charge during flight and/or rapid recharging especially when they are still hot. In the case of single cell, i.e., 1C batteries, the resting time is minimal. Tactile sensing of temperature should take into consideration that internal battery heat needs time to migrate out to the surface of the battery before it eventually dissipates into the air.

BATTERY CHARGERS: Small hobby entry level entry RTF or ARF systems come with the cheapest and least sophisticated battery chargers of all. While the led indicator indicates when the charge is complete... they may still trickle charge beyond that. The batteries are easily destroyed if charged above a specific voltage level or discahrged below 3.3 or 3.4 volts.

Until you get to a 2C battery, balancing is a feature that is not needed... More sophisticated chargers can balance charge and sense time and charge levels enabling them to shutdown automatically which is what one needs to protect their higher priced multiple cell, higher maH capacity batteries that can cost as much as $200 or more each.

 

[Carapau]

Breaking in batteries is a bit of a myth to be honest. There are no hard facts about how effective this is. However, given that it is hardly a faff to break batteries in so why not do it anyhow because it certainly wont harm the batteries.

As for keeping the batteries on the charger once the charge has finished. For the cheap chargers that come with some kits, then it might not be a good idea but if using proper branded chargers such as iCharger, Powerlab or even the Turnigy type knock offs, there is no problem keeping the batteries on them once the cycle has finished. Whilst I have not hard evidence on this, I have been flying lipos for years and often my batteries have been left on the chargers for a long time and I have witness no ill effects even with batteries that have 200+ cycles on them.

As for letting the batteries cool down post a flight before charging, again I often put the batteries on charge immediately post flight and again no ill effects. Many 3D pilots I know do exactly the same. And boy, flying a 700 class heli in hard 3D heats up the packs a treat. With that said, a bit like breaking in batteries, it can do no harm letting the batteries cool down before recharging.

 

[Skyguy]

Thanks to you all for your input and advice. Frankly, it sounds like each of you knows what you're talking about so I think my understanding has improved. I have to agree that it can't hurt to break in a battery, so I will continue doing that. Now that I know there's intelligent help available, I will feel pretty good about asking questions. Thanks again, guys. I really appreciate it.

Bruce