A Different Battery Question

We charged LFP battery installed in glider using charger plug that feeds the battery via glider electrical system. We discovered that there was automatic breaker hidden in glider electrical system (DG DEI) that stole little bit of voltage. This caused charger to not charge battery to full. It seems that you cannot have automatic breakers between charger and battery.

At 08:44 18 October 2019, krasw wrote:
We charged LFP battery installed in glider using charger plug that feeds
th=
e battery via glider electrical system. We discovered that there was
automa=
tic breaker hidden in glider electrical system (DG DEI) that stole little
b=
it of voltage. This caused charger to not charge battery to full. It
seems
=
that you cannot have automatic breakers between charger and battery.

Whenever you put any device is series, expect to lose something. For
example with a series diode expect to lose about 0.5volt.

For this reason many radio manufacturers use a back-biased diode across the
supply and a series fuse. In this way no current passes through the diode
unless you cross-polarity the radio, in case it will be a short to blow the
fuse.

On Friday, October 18, 2019 at 3:44:20 AM UTC-5, krasw wrote:
We charged LFP battery installed in glider using charger plug that feeds the battery via glider electrical system. We discovered that there was automatic breaker hidden in glider electrical system (DG DEI) that stole little bit of voltage. This caused charger to not charge battery to full. It seems that you cannot have automatic breakers between charger and battery.

KRASW - The voltage loss/drop across a breaker depends on the amp rating of the breaker. The smaller the rating the larger the drop.

For example, a small value 1A Tyco W32 breaker drops ~0.6Vdc. A 1A Klixon 7277 breaker can drop ~1Vdc! I always use a 5A or larger breaker. A clear case of "bigger is better".

See slides #95 for the full story at http://aviation.derosaweb.net/presen..._Made_Easy.pdf.