doc: Add warning about matching battery voltage.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/doc/altusmetrum.xsl b/doc/altusmetrum.xsl
index aa218c5cc598fffa26f33479ecc2cc8d2816a4d6..e7ab353bbd2ef171107f6f937048cc476845a657 100644 (file)
--- a/doc/altusmetrum.xsl
+++ b/doc/altusmetrum.xsl
@@ -279,14 +279,16 @@ NAR #88757, TRA #12200
     </para>
     <para>
       The battery connectors are a standard 2-pin JST connector and
-      match batteries sold by Spark Fun. Other vendors sell similar
-      batteries for RC aircraft using mating connectors, however the
-      polarity for those is generally reversed from the batteries used
-      by Altus Metrum products. In particular, the Tenergy batteries
-      supplied for use in Featherweight flight computers are not
-      compatible with Altus Metrum flight computers or battery
-      chargers. <emphasis>Check polarity before connecting any battery
-      not purchased from Altus Metrum or Spark Fun.</emphasis>
+      match batteries sold by Spark Fun. These batteries are
+      single-cell Lithium Polymer batteries that nominally provide 3.7
+      volts.  Other vendors sell similar batteries for RC aircraft
+      using mating connectors, however the polarity for those is
+      generally reversed from the batteries used by Altus Metrum
+      products. In particular, the Tenergy batteries supplied for use
+      in Featherweight flight computers are not compatible with Altus
+      Metrum flight computers or battery chargers. <emphasis>Check
+      polarity and voltage before connecting any battery not purchased
+      from Altus Metrum or Spark Fun.</emphasis>
     </para>
     <para>
       By default, we use the unregulated output of the Li-Po battery directly
@@ -492,7 +494,7 @@ NAR #88757, TRA #12200
       <para>
         You can monitor the operation of the radio link by watching the 
         lights on the devices. The red LED will flash each time a packet
-        is tramsitted, while the green LED will light up on TeleDongle when 
+        is transmitted, while the green LED will light up on TeleDongle when 
         it is waiting to receive a packet from the altimeter.
       </para>
     </section>