[chbot] LiPo batteries

[Mark Beckett]

Thats hardley micro backup ...its more like auxillary power.

No I don't have a supplier ...I've just has some multi cell arrive from 
Hobby King, and I've had some single cell from DX in the past.
/The best buy was Corey spotted Dick Smith Riccarton getting rid of 
their Parrot ARDrone 11.1v 1000mA 10C batteries for just under $4 
each....I got all 9 of them.../

As I said most of the RC type LiPo have ZERO protection.

Not sure of how useful the bags are, but i can make enquiries.
You're right not explosive proof

I have a pre-release version the article, but it will be out soon.

Some of the SeeedStudio Arduino boards (Stalker) had built in cell 
charging (I think it was LiPo)
You could look at their open source circuitry.


Mark


Volker Kuhlmann wrote:
> Hi Mark,
>
> Thanks for the good info!
>
> Multi-cell makes it more complicated hence my plans for 1-cell. If I
> find I really need 5V I'll use two (and think about the charging then).
> The bigger the better for the same effort, so I was eyeing up the 5Ah
> range ones, like
> http://www.hobbyking.com/hobbyking/store/__18560__Turnigy_5000mAh_1S_20C_Lipoly_Single_Cell_.html
> Although made for high-Amps, if it keeps a micro going for a day or two
> in the next desaster that'd be splendid, so I'm looking at 0.5A very max
> discharge and thus that's not the problematic aspect.
>
> On Fri 17 May 2013 11:42:01 NZST +1200, Mark Beckett wrote:
>
>   
>> The cheap RC type LiPo offer no protection against damage, and don't
>> incorporate any battery management on board the battery.
>> This includes any thermal device to open the connection when the
>> discharge is too great.
>>     
>
> Do you have a good source for them? Or how exactly is it described if
> that protection is included? (Hard case not needed for me.)
>
> Does that include *dis*charge protection as well? As in does it cut the
> load below a certain cell voltage?
>
>   
>> The RC car club requires them to be charged in the special bags you can get.
>>     
>
> Those bags don't look to me like they could contain a fire much. Control
> a little bit, yes, but they'd still do nothing about the impressive
> mess. Yes I'd use them (pityful price anyway), but better assume they're
> not there.
>
>   
>> And then of course there are those itoys that decided to commit
>> suicide and catch fire ...
>>     
>
> yep...
>
>   
>> If you look in the June Silicon Chip, Stan Swan has a write-up about
>>     
>
> If you mean http://www.siliconchip.com.au/ the June issue isn't there
> yet.
>
>   
>> In circuit charging is unlikely to be of a rate high enough to
>> generate the amount of heat required.
>>     
>
> Uhhhm, I have been warned that there is no safe limit of continuous
> charge, and all the energy is stored up and at some point, things *will*
> get interesting! In contrast, NiMH go over to an oxygen-recombination
> cycle that converts the surplus energy into heat and doesn't damage the
> battery provided you stay below some limit (in the order of 0.5-5% C).
> I'd probably use an integrated LiPo charge controller because it's less
> risky.
>
> Volker
>
>