Lithium battery article

[mojoman]

Great info on lithium battery care.
http://powerelectronics.com/mobile/prop ... ife?page=1

[markopolo]

Avoid charging to 100% capacity - Selecting a lower float voltage can do this.

If you have solar then maybe set the output voltage so as to not fully charge the battery when in storage.

[gcvt]

Interesting read - thanks for posting. Now, if they would just come down in price. Yikes.

[gerrym51]

Originally Posted by gcvt

Interesting read - thanks for posting. Now, if they would just come down in price. Yikes.

tppl agm's might be a good middle ground-almost(i said almost) as good as lithium

[booster]

Originally Posted by markopolo

If you have solar then maybe set the output voltage so as to not fully charge the battery when in storage.

That is kind of contrary to all the stuff the said about not putting them on float charge, kind of contrary, I will have to read again.

I think what they are saying in one place in the article is that if you have a charger, either shore, alternator, or solar, that determines full charge by ending amps, you can just set the ending amp higher to get it to stop earlier. It would have to be a full shutoff, however, not the more typical in RVs move to float. Those functions may be programmable into the BMS systems that you can get with the lithium batteries, but don't know for sure. If it is in the BMS, then you could just use a constant voltage charger, which would be a big plus.

[markopolo]

Probably not typical float mode as we know it. More of a constant voltage as you said but lower than what would fully charge the battery.

Might be better to just shut of the solar if the RV is stored for a month or so. That type of battery will be happy sitting at 80% SOC for example.

I still have a lot to learn before I can say I understand how to care for lithium batteries.

[booster]

I just did a little reread of the article. It appears he is calling the float voltage what we would be calling the absorption voltage. You may want to take a look to see if I am reading what he is saying correctly, though.

[markopolo]

I did read through it just now but struggled a bit. My interest is in LiFePO4, LFP or Li-phosphate batteries for RV use. It seems that the various lithium-ion chemistries have specific care requirements.

The 4.2v mentioned throughout the article would not be suitable for RV use (4 x 4.2v = 16.8v). The battery bank would have to be disconnected from the coach. 16.8v is too high.

This article - http://www.powerstream.com/LLLF.htm gives more info but it is still not clear to me if charging at 14.4v will fully charge a LiFePO4 battery bank.