{"id":553,"date":"2015-07-06T12:04:40","date_gmt":"2015-07-06T11:04:40","guid":{"rendered":"http:\/\/axotron.se\/blog\/?p=553"},"modified":"2015-07-22T08:37:21","modified_gmt":"2015-07-22T07:37:21","slug":"voltage-delay-in-lithium-thionyl-chloride-batteries","status":"publish","type":"post","link":"https:\/\/axotron.se\/blog\/voltage-delay-in-lithium-thionyl-chloride-batteries\/","title":{"rendered":"Voltage Delay in Lithium Thionyl Chloride Batteries"},"content":{"rendered":"

As I described in a previous post, I built a simple Teensy-controlled battery tester for Lithium Thionyl Chloride batteries<\/a>. I had noticed that unused batteries that had been laying around, seemed to have high internal resistance and according to Wikipedia<\/a>, this can be due to a passivation layer that forms on the anode and which causes a “voltage delay” when put into service.<\/p>\n

I decided to test this using the battery tester. What I did was to modify the program I had written for it so that it loaded the battery with a constant 5 mA current while monitoring how the pole voltage developed over time. I did this three times for one minute with a few minutes of pause in between for the same previously unused battery which has been stored for at least three years. The battery type is a 1\/2 AA size Tadiran TL-5101\/P.<\/p>\n

Below are plots showing the how the pole voltage varied during the tests. The three curves shows the result of the initial test (red), second test ~20 minutes later (blue) and third test ~10 minutes after the second test. The first plot shows 60 seconds while the second plot zooms in on the first 3 seconds.<\/p>\n

\"Voltage<\/a>
Voltage vs time during 60 s while loading the battery with 5 mA.<\/figcaption><\/figure>\n
\"Voltage<\/a>
Voltage vs time during 3 s while loading the battery with 5 mA.<\/figcaption><\/figure>\n

The pole voltage does indeed increase at first (during 3-10 seconds) while the battery is being loaded before it starts drooping. Also, the voltage under load becomes higher the second and third times the battery is tested in this manner.<\/p>\n

So a very short and simple test under load might give a too pessimistic view of the state of a lithium thinoyl battery that has been stored for an extended period of time. It might recover and start perform better while it is being loaded. This is somewhat counterintuitive.<\/p>\n

The Teensy program I used to for the tester can be found here<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

As I described in a previous post, I built a simple Teensy-controlled battery tester for Lithium Thionyl Chloride batteries. I had noticed that unused batteries that had been laying around, seemed to have high internal resistance and according to Wikipedia, this can be due to a passivation layer that forms on the anode and which … Continue reading Voltage Delay in Lithium Thionyl Chloride Batteries<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10,2,16],"tags":[],"class_list":["post-553","post","type-post","status-publish","format-standard","hentry","category-arduino","category-electronics","category-orienteering"],"_links":{"self":[{"href":"https:\/\/axotron.se\/blog\/wp-json\/wp\/v2\/posts\/553","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/axotron.se\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/axotron.se\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/axotron.se\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/axotron.se\/blog\/wp-json\/wp\/v2\/comments?post=553"}],"version-history":[{"count":7,"href":"https:\/\/axotron.se\/blog\/wp-json\/wp\/v2\/posts\/553\/revisions"}],"predecessor-version":[{"id":562,"href":"https:\/\/axotron.se\/blog\/wp-json\/wp\/v2\/posts\/553\/revisions\/562"}],"wp:attachment":[{"href":"https:\/\/axotron.se\/blog\/wp-json\/wp\/v2\/media?parent=553"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/axotron.se\/blog\/wp-json\/wp\/v2\/categories?post=553"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/axotron.se\/blog\/wp-json\/wp\/v2\/tags?post=553"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}