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Old January 5th 21, 06:41 PM posted to rec.aviation.soaring
Eric Greenwell[_4_]
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Default Solar panel controller

Dan Marotta wrote on 1/5/2021 8:19 AM:
On 1/4/21 6:35 PM, 2G wrote:
On Monday, January 4, 2021 at 3:32:11 PM UTC-8, Dan Marotta wrote:
On 1/4/21 2:22 PM, 2G wrote:
On Monday, January 4, 2021 at 7:41:18 AM UTC-8, Rhubarb wrote:
https://airbatt.de/navi.php?a=9114&lang=eng

Unfortunately they don't ship to countries outside of Europe.

Tom

I have one of these:
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

--
Dan
5J

Besides been quite large and unavailable, it is not for use with LFP batteries.

Tom


Oops, I thought the thread was about charge controllers, not about the batteries they're charging.

There ARE MPPT chargers suitable for LiFePO4, however.* They do cost quite a bit more but they
deliver a higher percentage of the energy to the batteries.

For glider use, they may not be worth the extra size, weight, and cost. It depends on the solar
panels, and the ones for gliders are usually chosen to optimize charging of 12 volt batteries
with PWM charge controllers, and using an MPPT controller on those panels will gain little
extra charging.

If the panels could be rewired in series instead of in parallel, the MPPT controller may
improve the charging rate. It's possible the constant changing of panel orientation in flight
may render the MPPT controller ineffective; on the ground it's probably similar to an RV, where
the range is often given at 10%-30% short term improvement, and perhaps as much as 15% average
over a few months use.

I've been researching this issue for my motorhome; currently (little pun there), I'm leaning to
doubling the size of the system as simply and cheaply as possible by duplicating the system it
already has, and paralleling the output from the two PWM controllers to the battery. If actual
usage shows another 15% charging would be worthwhile, I'll replace the PWM controllers with
MPPT units at about $200-$300 additional parts cost. I suspect additional batteries will be a
better way to spend $200, however.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1