<font size=2 face="sans-serif">Hi:</font>
<br>
<br><font size=2 face="sans-serif">We've done some testing and operation
of Lion battery banks in the 10 kWh range with our inverter chargers and
so far the most important findings are:</font>
<br>
<br><font size=2 face="sans-serif">1. The battery pack must have its own
battery management system to:</font>
<br><font size=2 face="sans-serif">a. regulate the individual cell voltages
during charge and discharge</font>
<br><font size=2 face="sans-serif">b. balance the cell voltages during
charge and discharge</font>
<br><font size=2 face="sans-serif">c. adjust cell charging voltages due
to temperature variations</font>
<br><font size=2 face="sans-serif">d. not provide a continuous float voltage
to the battery bank</font>
<br><font size=2 face="sans-serif">d. provide a built in safety cutoff
disconnect, which turns off the current if for any reason either the charge
or discharge current is too high.</font>
<br>
<br><font size=2 face="sans-serif">A series string of Lion cells, without
the battery management system functions above is very likely to result
in damaged cells or worse. The most likely mechanism which ultimately
causes damage is individual cell temperature or cell to cell voltage imbalance.
</font>
<br>
<br><font size=2 face="sans-serif">2. The inverter system must be designed
so that the inverter never draws so much current that the current limit
circuit in the battery bank is triggered. </font>
<br>
<br><font size=2 face="sans-serif">3. It may be necessary to adjust the
current limit circuit as they typically respond within milli-seconds and
may be triggered on simple power up as the inverter cap bank charges up.</font>
<br>
<br><font size=2 face="sans-serif">4. When working with Lion, the inverter/charger
should be configured so that it is a simple current limited voltage source
when in charge mode. The built in battery management system should
take care of the required charge cycle operation.</font>
<br>
<br><font size=2 face="sans-serif">5. Whether the pack is LiFePO4, Lion
polymer or other does not appear to be as important as a having a reputable
brand and more importantly a well designed built in battery management
system.</font>
<br>
<br><font size=2 face="sans-serif">The short version is that lead acid
cells are amazingly forgiving with regards charging and discharging voltages,
currents and temperatures. Lion cells on the other hand are amazingly
sensitive and going out of bounds on any of these can and will cause irreparable
damage. </font>
<br>
<br><font size=2 face="sans-serif">Given the sensitivity, it doesn't make
sense to take on responsibility for Lion battery management.</font>
<br>
<br><font size=2 face="sans-serif">Management of that sensitivity and responsibility
is best left to the battery bank manufacturer. </font>
<br>
<br><font size=2 face="sans-serif">JARMO<br>
</font><font size=3 color=#008000>_____________________________________________________________________________________</font><font size=3>
<br>
</font><font size=1 face="Arial"><b><br>
Jarmo Venalainen</b> | </font><font size=1 color=#008000 face="Arial"><b>
Schneider Electric </b></font><font size=1 face="Arial"><b> | Solar
Business</b> | <b>CANADA</b> | <b>Training &
Development Specialist - Senior</b> <b><br>
Phone:</b> +604-422-2528 | <b>Fax:</b> +604-420-1591 |
<b>Mobile:</b> +604-505-0291 <b><br>
Email:</b> </font><a href="mailto:jarmo.venalainen@schneider-electric.com"><font size=1 color=blue face="Arial"><u>jarmo.venalainen@schneider-electric.com</u></font></a><font size=1 face="Arial">
| <b>Site:</b></font><a href=http://www.sesolar.com/ target=_blank><font size=1 color=blue face="Arial"><u>
www.SEsolar.com</u></font></a><font size=1 face="Arial"> |
<b>Address:</b> 3700 Gilmore Way, Burnaby, BC V5G4M1 <br>
</font><font size=1 color=blue face="Arial"><u><br>
</u></font><a href="http:// www.sesolar.com/"><img src=cid:_2_0CAB3C9C0CAC3DE0000BB99B88257D55></a><font size=1 face="Arial"><br>
*** Please consider the environment before printing this e-mail</font><font size=3>
<br>
</font>
<br>
<br>
<br>
<table width=100%>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">From:</font>
<td><font size=1 face="sans-serif">"William Miller" <william@millersolar.com></font>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">To:</font>
<td><font size=1 face="sans-serif">"RE-wrenches" <re-wrenches@lists.re-wrenches.org>,
</font>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">Date:</font>
<td><font size=1 face="sans-serif">09/15/2014 04:27 PM</font>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">Subject:</font>
<td><font size=1 face="sans-serif">[RE-wrenches] LiFePo4</font>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">Sent by:</font>
<td><font size=1 face="sans-serif">"RE-wrenches" <re-wrenches-bounces@lists.re-wrenches.org></font></table>
<br>
<hr noshade>
<br>
<br>
<br><font size=3 face="Arial">Wrenches:</font>
<br><font size=3 face="Arial"> </font>
<br><font size=3 face="Arial">Does anyone have any experience with Lithium
Ferrous Phosphate cells? What are your experiences? I am looking
at an installation tomorrow and would like some input.</font>
<br><font size=3 face="Arial"> </font>
<br><font size=3 face="Arial">Thanks in advance.</font>
<br><font size=3 face="Arial"> </font>
<br><font size=3 face="Arial">William Miller</font>
<br><font size=3 face="Arial"> </font>
<br><img src=cid:_2_0CA90C80069FDDD0000BB99B88257D55 alt="Gradient Cap_mini"><font size=2 face="Arial"><br>
Lic 773985</font><font size=2 color=blue face="Arial"><u><br>
</u></font><a href=http://www.millersolar.com/><font size=2 color=blue face="Arial"><u>millersolar.com</u></font></a><font size=2 face="Arial"><br>
805-438-5600</font>
<br><font size=2 face="Calibri"> </font>
<p><font size=3><br>
______________________________________________________________________<br>
This email has been scanned by the Symantec Email Security.cloud service.<br>
______________________________________________________________________</font><tt><font size=2>_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
List Address: RE-wrenches@lists.re-wrenches.org<br>
<br>
Change listserver email address & settings:<br>
</font></tt><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org"><tt><font size=2>http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</font></tt></a><tt><font size=2><br>
<br>
List-Archive: </font></tt><a href="http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html"><tt><font size=2>http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html</font></tt></a><tt><font size=2><br>
<br>
List rules & etiquette:<br>
</font></tt><a href="www.re-wrenches.org/etiquette.htm"><tt><font size=2>www.re-wrenches.org/etiquette.htm</font></tt></a><tt><font size=2><br>
<br>
Check out or update participant bios:<br>
</font></tt><a href="www.members.re-wrenches.org"><tt><font size=2>www.members.re-wrenches.org</font></tt></a><tt><font size=2><br>
<br>
</font></tt>
<p>
<p>