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<font size="2">John Veix wrote:
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<br />"<font size="2" face="Arial">I have a customer with a hot air balloon
(who) doesn't
want to use F.L.A. deep cycle battery due to weight factors, but wants to use Li
instead - and also wants to use PV to charge
it."
<br />
<br />Mick says: If one recalls the YouTube videos of flaming notebook
computers, that underscores the importance of proper management where the
lithium chemistries are concerned. (I believe) a charge algorithm for lead
batteries cannot safely be used with lithium.
<br />
<br />Southwest Electronic Energy:
<br />
<br />http://www.swe.com/default.aspx
<br />
<br />claims to have solutions for solar electric recharge of their lithium
packs. This may be a good contact to
pursue, but I have had no direct experience with
SWE.
<br />
<br />For lithium, I think you should seek a supplier that can offer
"single source accountability" where the cells, battery balance system
and the solar charge controller all come from the same vendor. Otherwise if
there are problems with these costly cells, the battery vendor could blame the
control regimen and the manufacturer of the power electronics could blame the
cell supplier. You want no finger pointing, no wiggle room and a single warranty
for the combined bundle of lithium pack plus "battery management
system"...and the "BMS" should include a solar charge control circuit for your described application.
<br />
<br />In terms of practicality, a 10 amp hour (12 volt nominal) lead battery
only weighs about 9 pounds. If lithium technology could reduce that weight by
2/3 you'll save 6 pounds but your client will pay dearly for it, and you'll wind
up with an exotic batch of gear that's not easy to service or plug in
replacement parts. Is it worth it? Be sure & report back to the List so we
can all
learn...
<br />
<br />Mick Abraham,
Proprietor
<br />www.abrahamsolar.com
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