On Thu, 17 Jan 2013 20:26:43 +0000, Roel Baardman wrote:

Can I briefly ask the naive question: What is wrong with a few lead
batteries? Weight? Installing/removing? The circuitry?

Space and weight, particularly if you fly an older glider and like to put
electronic toys in your cockpit.

The problems with anything much more exotic than sealed lead-acid gel
cells (SLA) are cost and the need for more intelligent (and expensive)
chargers.

That said, IMO you're cheating yourself if you don't use a charger that
can detect full charge, and hence won't over-charge the battery, and can
automatically cycle batteries and measure the battery capacity. Same goes
for buying cheap batteries: I like Yuasa SLAs, which reliably give me 3-4
years flying.

I cycle and test my batteries each winter and log the measured capacity
of each battery: this makes it really easy to see when one should be
replaced.

I use Sunpower multi-stage mains chargers for my SLA glider batteries and
never leave them partially charged: the batteries are put on charge as
soon as I get home from flying.

I have a fairly basic Pro-Peak Prodigy multi-chemistry charger (lead-
acid, NiCd, NiMH, Li-ion, Li-poly) that I use for testing the SLAs and
for charging and testing the other batteries I use in models, cameras,
etc. Pro-Peak and similar chargers are sold wherever you by RC and
electric model aircraft gear.

I also have a Vencon charger/cycler, but this is a beast of a very
different stripe: it is controlled and programmed by a management program
running on a Windows PC. This kit is not cheap, but if you're serious
about battery monitoring or have a lot of batteries that are used for
critical tasks its the one to use.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
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