Safety Third Lithium battery care tips thread

[Bartman]

guys,



would you mind if I merged this thread with the one on LiPo's that is already in progress here



http://giantscalenews.com/forum/showthread.php?775-Understanding-Lithium-Polymer-Batteries



??



Thanks,

Bart

 

[Xpress]

I wouldn't mind it so long as the title does employ the Safety Third common sense campaign. The whole point of this thread is just to use common sense when handling batteries

 

[stangflyer]

I am absolutely by no means a battery guru of any sort. Just know what has worked for me in the past and taking "good" advice from those that have been around them has certainly proved beneficial. I do have four 4S 5000 mah Lipo's that I use on my Aeroworks Freestyle 260 Extra. I have at this time, roughly 50+ charges on these batteries since I purchased them late last year. As it stands, none of them or puffing, or losing any amount of charging capability. But then, I've never had them hot, nor over charged them. And I do, balance them every single time I charge. Is this really necessary? Some say no. Others say yes. Not really sure. I just know what has been working for me.

 

[DeathHorse]

I like to keep track of IR readings and cycle them every once and a while to confirm capacity. This is on receiver packs.



If anything starts to go downhill it should show up in increasing IR over time. I write down the IR of each cell when I get the packs and monitor this over time. The IR should be fairly close between cells.



Always balance charge. Some chargers take forever, but if you can't check IR and have a weak cell, it will overcharge the weak cell and undercharge the normal cell (s). An easy way around a slow balancing charger is to charge the batteries on a parallel board. Connected in parallel the cells balance each other to a point, (in as much as where the voltages between corresponding cells equalize is probably closer to where they are supposed to be). The more batteries connected in parallel the more likely the voltage equalized between corresponding cells approaches the ideal, but even two batteries in parallel works surprisingly well.



My experience is there isn't much balancing left for the charger to do with two or more batteries connected to a parallel board. Just make sure the batteries are all the same chemistry, cell count and close to the same state of charge. Always connect the main leads first and let it sit for 30 seconds so the initial equalization current jolt goes through the main leads.



A running theme in Lipo fires is using the wrong charge settings. Having the balance wires plugged in and letting the charger detect the cell count goes a long way towards preventing these mistakes. This is speculation, but I'll bet a higher proportion of people charging batteries in their plane use the main leads only without balance cables compared to those charging batteries outside the plane. Without the balance leads a dying cell being overcharged or the wrong settings could cause a fire. Some chargers are safer than others when it comes to auto detect features and whether the balance leads need to be connected.

 

[Xpress]

stangflyer;18679 wrote: I am absolutely by no means a battery guru of any sort. Just know what has worked for me in the past and taking "good" advice from those that have been around them has certainly proved beneficial. I do have four 4S 5000 mah Lipo's that I use on my Aeroworks Freestyle 260 Extra. I have at this time, roughly 50+ charges on these batteries since I purchased them late last year. As it stands, none of them or puffing, or losing any amount of charging capability. But then, I've never had them hot, nor over charged them. And I do, balance them every single time I charge. Is this really necessary? Some say no. Others say yes. Not really sure. I just know what has been working for me.

I balance charge every time. If one cell gets even 0.2v out of balance it can begin to degrade the whole pack. This is where a lot of people end up losing their batteries.

 

[Bartman]

Xpress;18648 wrote: I wouldn't mind it so long as the title does employ the Safety Third common sense campaign. The whole point of this thread is just to use common sense when handling batteries

is "Safety Third" a hobby-wide campaign or are you the creator of it?

 

[stangflyer]

Xpress;19026 wrote: I balance charge every time. If one cell gets even 0.2v out of balance it can begin to degrade the whole pack. This is where a lot of people end up losing their batteries.

So I wasn't loosing my mind then? One time I was at the field and I had spent my four 4s's. I wanted to keep flying so a friend said, "Here, just use my charger to charge them". "You don't need to balance them every time". Well, that being said, I really noticed a difference in those two packs I charged. It took three times balancing to get them back to where they have always been. As I said, I am no battery guru....but I "do" know what has been working. If it ain't broke, don't fix it, right?

 

[SlowHuck]

Bartman;19038 wrote: is "Safety Third" a hobby-wide campaign or are you the creator of it?

The concept originated with Mike Rowe of "Dirty Jobs" fame. He refers to it just as Xpress states it...

" ...while safety equipment, procedures, OSHA and all that are important, it is not a replacement for good old fashion common sense."​

www.mikeroweworks.com "Safety Third - Huh?"

 

[Xpress]

Bartman;19038 wrote: is "Safety Third" a hobby-wide campaign or are you the creator of it?

As stated above I'm not the creator of the concept, merely a messenger. The point is to highlight the use of common sense rather than relying 100% on what you're told.

stangflyer;19045 wrote: So I wasn't loosing my mind then? One time I was at the field and I had spent my four 4s's. I wanted to keep flying so a friend said, "Here, just use my charger to charge them". "You don't need to balance them every time". Well, that being said, I really noticed a difference in those two packs I charged. It took three times balancing to get them back to where they have always been. As I said, I am no battery guru....but I "do" know what has been working. If it ain't broke, don't fix it, right?

Some batteries are really sensitive to being balance charged so i just do it with every battery. It helps to prolong the life of the pack.

 

[Robotech]

In the case of A123s, there is no good reason not to balance charge them every time. I can't speak to LiPos as I have never used them.