[Noisebridge-discuss] [HBRobotics] High density 2S LIPO with Charge/Discharge cutoffs - Brainless Battery Pack?

[Taylor Alexander]

> For all intents and purposes, a 9v DC source should be all that is needed
> to charge this pack.


I don't know specifics, but I'm inclined to believe that isn't the case. The
protection circuits are only there to prevent overcurrent and over/under
voltage conditions. They don't do any charge current regulating and I'm
pretty sure LiPo cells want that. At least, I do know that even though all
of Sparkfun's single cell battery packs have protection circuits, they
always say you need a lipo charge circuit and I've never heard anything
about charging a LiPo off straight DC. Given how handy that would be, I'm
inclined to believe I would have heard something about that.

So like I said, I don't know anything for sure, but if you don't either,
then there's probably more to it. Either way its something you should
definitely be sure of before trying.

-Taylor




> As long as you only need to provide 7.4 volts at 8 amps, you should be
> fine.  This pack only has two leads.  That's for voltage in and out.  No
> LIPO charging equipment required.  My expectation is that there is some
> circuitry in the pack that does this for you.
>
> On Wed, Sep 14, 2011 at 11:04 AM, William Garrido <
> blackspartan117 at gmail.com> wrote:
>
>> Nice! This would be great to drive my motors. I doubt my charger for LiPo
>> would work, anyone know if a small LiPo charger for 2S? I have my
>> chargers embedded on my robot.
>>
>> Or even my MC, would get rid of the need for a stepup! Too bad its not
>> 6AH.
>>
>>
>> On Wed, Sep 14, 2011 at 10:10 AM, Corey McGuire <coreyfro at coreyfro.com>wrote:
>>
>>> Need to replace NICAD/NIMH packs, but are afraid of the complexity of
>>> LIPO or added charger cost?  This pack might fit your bill.
>>>
>>>
>>> http://www.hobbyking.com/hobbyking/store/__19481__Turnigy_4000mAh_Spektrum_DX8_Intelligent_Transmitter_Pack..html
>>>
>>> Sparkfun and other places have single cells that have such cutoff
>>> circuitry to protect your single cell from being charged too high or
>>> discharged too low, but this is the first 2S solution I've seen. 2S LIPO is
>>> a sweet spot because it nearly perfectly matches the voltage characteristics
>>> of 6 Cell NICAD/NIMH packs, which are common everywhere.  This could be a
>>> drop in replacement for such needs.
>>>
>>> One draw back, it appears to provide only 8 amps of current.  This is, no
>>> doubt, because the circuit that regulates charge is in line with whatever
>>> you plug it in to.
>>>
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>>
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>
>
>
> --
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