Another Lithium Ion batteries question

Hey Pnick, that is pretty much how you charge all LI (well at least LiFePo4 batts). If you build your own pack, battery prices are close to $1/Ah now.

RambleOnNW wrote:
The lithiumion-batteries.com link when clicked says "Account has been suspended". On further edit their Better Business Bureau rating is F. The complaints show they have been failing to deliver product.

Yeah....I just posted that link Saturday. Sunday it still worked, but yesterday it didn't. Now the link works again ... I guess they paid their hosting bill!:

http://www.lithiumion-batteries.com/lithium-rv-deep-cycle.php

I've been watching this company for a couple of years now. I really like their turn-key drop-in approach so you can use their lithium RV battery right in the same mounting place as where your lead acid RV batteries would go, as they come in standard 12V automotive sizes.

Here's a link on charging of their LI RV batteries:

http://www.lithiumion-batteries.com/smart-battery-charging.php

Here's a paragraph I clipped from the link above, implying that even many existing chargers in RVs might be able to be used to charge them:

"Smart Battery Lithium Ion Batteries need to reach between 14.4V and 14.6V during charging to reach a full charge. If your charger voltage is much higher than this and cannot be programmed to a lower voltage it is not recommended for use with our batteries. If the voltage is much lower this is OK to use with our batteries. Depending on how much lower the voltage is it may not fully charge the Smart Battery Lithium Ion Battery. A good range to keep within is 14.0V - 14.8V this will average 85% - 100% charged."

Build you own is the cheapest way to get into this but it does require some research. The hardest part is figuring out which BMS to get IMO. It seems the supply channel has improved now too so getting batteries isn't as difficult as before. Visit the DIY EV forums and just use what everyone else uses. That's the safest bet.

diyelectriccar.com

The lithiumion-batteries.com link when clicked says "Account has been suspended". On further edit their Better Business Bureau rating is F. The complaints show they have been failing to deliver product.

For charging Lithium Ion batteries, Progressive Dynamics has a lithium ion battery charger.. They also mention output voltage can be factory adjusted to meet battery OEM requirements. Lithium Ion batteries do not like to be trickle charged when fully charged.

Also noticed they link to Starkpower, which has a 100AH battery for $899.

Hi Phil,

Yes the weight is nice.

Here is the reply I got when I asked about using them at -40. It is not too helpful.

The original question:

Hi, Can your jars be used at -40 C? Would there be special requirements for charging at -40 C?

The reply:

Don,

Yes the batteries can be used at -40c if you use a low wattage heat pad or blanket around the battery.


Best Regards,


Sales Engineer
Smart Battery®

I know nothing about the lithium batteries used for automotive use, but they are the battery of choice for Radio Control cars and planes. The fly in the ointment is the safety in charging these batteries. If not done safely and properly, they will cause early failure and a fire is a real threat.
So the charging system would have to be designed to safely charge them. Probably completely different than regular automotive batteries as we know them now.

Don,

How do you like the (lack of) weight on that 300 amp-hour LI beauty?!

(I wonder if I could still use my Parallax converter + Sears charger to take care of one? :B )

Hi Phil,

Well, this is the one I would choose:

300 amp-hour LI

I'd want two, so it would cost $7k

For an AGM I'd need four and cost would be close to $3k

Too bad they don't have a 12 volt 400 amp-hour box. That would be more or less a replacement for the bank I have now (when it was new).

I've emailed them about cold weather use.

reed cundiff wrote:

There are arguments going back and forth among LFP users about using battery management systems (BMS)or close monitoring of cells with Fluke meters.

What Reed means here is that LFP (LFP=LiFePo4 is in the lithium ion "family") cells need to be "balanced". Unlike lead acid batts where each cell will balance themselves (balance = same voltage on each cell), LFP batteries can't do that. You have to perform that task manually (volt meter) or have a BMS system do that for you. The reasoning for cell balancing is you don't want to overcharge a cell. Overcharging LI batts will kill them.

Son is in solar and he recently attended a symposium where they believe that costs for lithium iron phosphate will drop by 50% within next two years. This would mean that a 10 kW-hour system would costs about $1500. This is 8 kW-hours of usable energy since 80% DOD should (according to tests run by Liberty Coaches for their $1.8 M and up Liberty Ladies) last 2000 to 3000 full cycles or about 10 years without degradation. I believe that they have three battery banks for a total of about 27 kW-hrs. This is a surcharge of $21K. I suppose if you can afford what is basically a $2M US rig, a 1% surcharge is pocket change. There is a thread on this forum where Liberty Lady coach owners discuss their use.

There are arguments going back and forth among LFP users about using battery management systems (BMS)or close monitoring of cells with Fluke meters. We opted for BMS since monitoring 16 cells is more than we care to do. AM-Solar is investigating LFP and is working with a fabricator for possible solar systems in the future.

Our system is 4 batteries of 4 cells in series (12 V nominal). These batteries are themselves in series to provide a 180 amp-hr 48 V nominal (720 amp-hr equivalent at 12 V nominal). This is approximately 9.6 kW-hours.

Folks that post about using LFP seem to universally like them. But there are a lot of naysayers (one Ontarian calls them Leadites). Undoubtedly a lot more folks will be utilizing this technology as (provided they do) prices drop.
Reed and Elaine