23 replies to this topic

[JaSAn]

While researching solar for my Grandby last winter, I studied LiFePO4 batteries.  My conclusion was that the technology was not mature enough for me to tackle.

 

Best discussions I found on LiFePO4 come from the cruising world.

 

MaineSail shares a lot of good knowledge:

http://www.pbase.com...on_boats&page=1

 

If you want a very complete discussion on their use for house batteries:

http://www.cruisersf...anks-65069.html

Lots of arguing and disagreements that you have to wade through (over 4000 post long), but it and the referenced earlier posts will give a good understanding of the issues.

 

jim

[enelson]

So far I'm very satisfied with the LiFePo I've installed.  We camped in Winter Park, Colorado this weekend and running the furnace, frig, lights, battery management system, and gas safety sensors we dropped from 98% to 84% capacity overnight.  The nighttime low was around 14 degrees F.  Winter camping is pretty addictive in a camper that is set up for it like our Hallmark.

 

The only thing that I'm less than 100% pleased with is risk of damage to the batteries during cold weather charging.  The word out there is that the charging must be kept at capacity divided by 30.  It isn't clear exactly what temperatures are too cold for my particular batteries and the spec sheet seems way too optimistic  http://en.winston-ba...category_id=176

.  I may move the batteries from the forward battery compartment a position under the dinette seating to allow them to benefit from the furnace heat.

Edited by enelson, 12 January 2015 - 05:02 PM.

[BobM]

Being an Ebike owner I have a lot of experience with Lithium batteries. They are very expensive compared to lead acid. Not only because the lithium is more expensive but they require a computer that manages both charging and usage/heat etc. Without a good computer they will explode. They don't charge well if it's cold. I put mine in an ice chest (to retain heat) to charge during the winter when I charge them. They should never be fully discharged.

For the bike, their light weight to power ratio makes the expense worth it but I just don't see them ready for our campers yet, IMHO. But also, after a year on my bike the batteries only last about half the distance of when new. They also power off multiple times when going up hills probably because a weak cell starts to overheat.

[enelson]

There are many types of lithium chemistry used in batteries.  I would guess that your ebike uses something like lithium ion or lithium polymer batteries.  The lithium iron phosphate do not have the same fire / explosion risk as other chemistry but are not as high performing either.  Here is something to consider

Edited by enelson, 12 January 2015 - 08:35 PM.