[Power] [support-gang] External "power bank" for XO's ?

[T Gillett]

Nathan

I have tried to standardise on 12V powered gear as it really makes it
simple for field work.
SLA batteries and chargers are pretty cheap and readily available.

Like you, I also found trying to work from 5V battery packs with step up to
12V to be problematic.

Thanks for the link, that is a nice board for a solar powered system. It
would be good to find one that does the load cut off at low battery as well.

The unusual sized power connector on the XO is a bit of a problem to find
replacement parts, but they are around.
It is the small centre conductor version (? 1.7mm) that seems hard to find.

I have also found that with age the connectors on the chargers don't make
good contact as the V shaped centre contact spreads apart. But they can be
pushed/bent back into the middle of the connector to extend their life.

On Tue, Jan 26, 2016 at 12:01 PM, <nathanr333 at charter.net> wrote:

> Terry,
>
> Again, thanks for suggestions.
>
> I do have the 3 A version (slightly lower cost) of this board.  It also
> permits charger input instead of solar.   OLPC chargers  ( 12 V and 13.5 V)
> would not work since module is only voltage bucking device and lead/acid 12
> V batteries are about 14.3 V at full charge.  (In my solar application,
> this board feeds a Li battery charging/protection board for 14 V  output).
>
> I have used a 5 V  to 12 V boost board enough to know that XO-1 requires
> almost 1 amp to start and about 3/4 amp to run. The 5 V had to supply the
> board at least 2.5 amp at start.  This beyond the output of maximum of 2.1
> amp of most 5  V "power banks".
>
> A hard part is getting  the XO compatible connectors needed.  :(
>
>
> http://www.ebay.com/itm/BQ24650-5A-MPPT-Solar-Panel-Lithium-Lead-acid-Battery-Charging-Controller-Board-/171753976645?hash=item27fd55b345:g:H9QAAOSwMmBVuyYI
>
> Nathan
>
> -----------------------------------------
> From: "T Gillett"
> To: "Community Support Volunteers -- who help respond to help AT
> laptop.org"
> Cc:
> Sent: Tue, 26 Jan 2016 08:47:12 +1000
> Subject: Re: [support-gang] External "power bank" for XO's ?
>
> Ahhh  I see we have additional requirements to meet...
>
> Travel and shipping requirements for small, non-spillable batteries (<100
> Watt Hours) are not that onerous.
> If they are properly installed within a piece of equipment that is
> prevented from being accidentally switched on, then you have met the rules
> and won't attract undue attention.
>
> Lithium based batteries do require additional care and can attract extra
> attention however, simply due to their chemistry and the possibility of
> burning.
>
> I imagine you don't want to modify the XO so that it retains its
> qualification for travel and shipping. The goal is just to have an
> additional source of power plugged in via the charging socket - correct?
>
> In this case you need a nominal 12V supply for the XO.
>
> A 12V battery mounted in a suitable enclosure with a switched, fused and
> pluggable output cable, combined with a matching plug pack charger would
> fit the bill. Such a thing is fairly easy to assemble, and you can probably
> do so for under $30 all up with a common 4AH SLA battery and a 1.25A
> charger.  Of course you can use other battery types as well.
> There are also commercial products like this, but perhaps not in as small
> a size as you are looking for.
>
> But if you must re-use the original XO charger, then it is going to be a
> little more complicated because you can't directly charge a 12V battery
> from a 12V supply. If you include a step up DC-DC converter with adjustable
> voltage and current then you can use that as a simple charger within the
> enclosure. Or use a more elaborate charge circuit.
>
>
> 1.25 A SLA Charger $8
>
> http://www.ebay.com.au/itm/12V-Volt-1250mA-Sealed-Lead-Acid-Rechargeable-Battery-Charger-SLA-Computer-AU-/190615897043
> 4AH SLA Battery  $14
>
> http://www.ebay.com/itm/Casil-Genuine-CA1240-12V-4Ah-SLA-Alarm-Battery-Brand-New-2016-/291575671757
> DC-DC Converter $3
>
> http://www.ebay.com.au/itm/Boost-Buck-Voltage-LM2577S-LM2596S-DC-DC-Step-Up-Down-Power-Converter-Module-/191149033807
>
>
> On Tue, Jan 26, 2016 at 4:42 AM, <nathanr333 at charter.net> wrote:
>
>> Terry,
>>
>> Thanks for suggestion.
>>
>> Since XO LiFePo4 batteries are no longer manufactured, I am looking for a
>> means of battery power when current batteries reach short run times near
>> end of usefull life.  The targeted features sought are: fit in a small
>> brief bag with XO, can be carried on airplane, can be mailed  with an XO,
>> cost similar to XO battery and use XO  charger.  The devices mentioned met
>> some of the features:   about the size of my hand, similar or greater run
>> time, cost equal or slightly higher than XO battery, certified for
>> transport and mailing, and in some cases could use XO charger.
>>
>>  They do  cost 2X of a sealed (gel) lead/acid battery with charger.
>>
>> Posted earlier that I have been able to rebuild an XO battery using 4 of
>> 18650 cells and a slight modification of the battery case.    However,
>> these would not be qualified (certified) for transport or mailing.
>>
>> Hence, looking around for what might be available and continue to be
>> available.
>>
>> Nathan
>>
>
>
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