Re: What to do with LiFePO4 batteries when the boat is layed up?


Joerg Esdorn
 

Thanks very much, Scott.  You certainly are putting a lot of effort into your posts!  I am sceptical as well of the MV support guys’ claim that his batteries are différent but MV’s advice to keep the batteries at 100% is out there right in their manual.  Why would they recommend something that is proven to be detrimental to the batteries?  

Thanks also for sending the article.  Having been an engineer in my first life and having done university level research work myself, I’m highly sceptical of the results of the simplified test for a number of reasons.  First, there is no indication that the researcher has any qualifications whatsoever - on his linked in page he’s described as a sales manager.  So I’m not sure of his motivations for writing the article.  Second, there is just ONE test run with ONE set of discharge and charge parameters.  These small differences he’s measured are they repeatable or could they be the result of variations between the cells, for example.  Also, a serious researcher would always run various parameters to see whether there are relationships between the outcome and your parameters.    For example, I charge my batteries at less than 25% of capacity because that’s all my chargers can do and at the the very end of the charging process my chargers would go into float, so the charge goes down to a few amps.  His test was at a charge rate of 50% of capacity - until full? If so, wow!  He’s also discharging the cells to 2.0V - my batteries would never go down so low because of the BMS.  Even more importantly, the cells he’s tested - are they what I and you have?  He used 1.5Ah capacity cells - that’s pretty small.  What is the testing setup he’s used?  Testing such minuscule voltage differences must require some expensive equipment, right?  

So I have a lot of questions and see this «test » more as the typical pseudo science that unfortunately pervades social media.  I’m curious to see whether there is any serious research out there.  Thanks again for your and everyone else’s thoughts! 

Joerg Esdorn
A55 #53 Kincsem
Currently cruising Brittany    

  

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