[time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.

[Poul-Henning Kamp]

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Bob kb8tq writes:

>Properly charging batteries is a bit complicated.

With VRLA lead-acids:  Not really, constant voltage 2.3V/cell, current limited to $Ah/10 and you're done.

For the tonnage of batteries relevant for us, when used indoors, temperature-compensation and all that is not relevant.

Charging Lithium on the other hand is several kinds of nightmares, many of them involving unquenchable flames.

>One “cute” alternative is to do a battery + boost converter ( = switcher) instead.
>[...]
>The advantage of a switcher is obviously efficiency. A fully charged “12V” LiFePo4 stack could easily be at 14.8V.
>Fully discharged it might get down to 10.4V. Allowing for that 1.4:1 output ratio with a linear regulator means a 
>lot of (expensive) battery energy goes up in heat ….

Yes, for most stuff I would just slap a good isolated DC/DC converter on a single 12V battery and be done with it.

But for a BVA I would choose more expensive batteries over switching noise any day...

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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