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ghaynes755 · 01-09-2015, 04:12 PM

Just saw that AMSolar has listed 4 different sized Lithium (LiFEPO4) battery pack units on their website.

Since Lithiums can use 80% of capacity, something equivalent to 4 - 6V 220ah Lifelines with usable capacity of 220ah would be the 300ah Lithium pack.

The 4 Lifelines weigh in at 264lbs. The 300ah setup looks like it should weigh in at under 90lbs base on 4 of the 100ah. Might be different when all of the variations have full details.

Cost for the Lifelines at $1,340 vs $2,699 for the Lithiums. Lithiums are estimated to have a 3-5x longer expectancy of number of charges vs. AGM's so in the long run may be less expensive.

Exciting times.

KJRitchie · 01-09-2015, 04:24 PM

What about the chargers for these batteries? You can't use the same controlers and converters for the current battery techknogies in RVs.

Kelvin

dkottum · 01-09-2015, 05:20 PM

Exciting times indeed, a great companion to modern solar systems.

lewster · 01-09-2015, 05:43 PM

Since you mentioned it.................

I have been getting a ton of requests about lithium battery technology. Greg at AM Solar has spent the last several months working with this new formulation of lithium batteries (LiFeYPO-4)..... the Y stands for Yttrium. This new formula addresses one of the main drawbacks of the old formulation without the Yttrium. Previously, you needed to refrain from using the lithiums below freezing and especially when charging them, as temperatures below freezing had a serious negative affect on the battery chemistry that was permanent. This is not a problem with the new Yttrium formulation. This also eliminates the need for heated battery boxes for the old formula batteries.

These new batteries are complete with required cell voltage balancing electronics and a battery monitor system that will shut off the voltage draw before they reach the low voltage 'point of no return'. That was the other serious problem with lithiums.....draw them past their low voltage cut-off and they were TOAST!

I have the 2 X 100 amp/hours of the previous version of these batteries in my van and have been powering a 12VDC fridge (24/7) and 2800 watt Magnum sine wave inverter with them. Charging is from 5 X 100 Grape Solar Photo Flex panels and the Blue Sky 40 amp 3024iL solar charge controller. The batteries have been at 100% before noon every day.

I have a new set of the Yttrium formula lithiums coming soon. BTW, the present lithiums that I have weigh about 56 lbs. and they replaced a pair of Lifeline GPL-6CT AGM 6VDC golf cart batteries that weighted just shy of 200 lbs.

Once everything is sorted out, the new lithium formula is expected to last over 5000 charge cycles, or 5 times that of AGM batteries at 50% depth of discharge. The initial expense will quickly be absorbed by the longevity of this new technology, and they could easily be the last trailer battery that you ever buy!

Charging requires a CC/CV (constant current/constant voltage) charge profile. This is easily done with a Magnum inverter/charger, as both the ME-RC and ME-ARC remote panels have the necessary firmware for this with a CC/CV setting in the charge profile. Blue Sky solar chargers can also be set for this type of specialized charging. Our familiar 3-stage chargers WILL NOT WORK! I'm sure that the converter manufacturers will be addressing this requirement soon.

I will be keeping close track of the new batteries once they arrive and will start a thread for them.

kscherzi · 01-09-2015, 05:57 PM

Thanks for the update Lew. Out of curiosity how big are the lithiums? Are they a similar dimension to the group 24s or golf cart batteries?

vinstream · 01-09-2015, 06:04 PM

After they figure out the overheat and fire issues.... All joking aside I like the weight to storage capacity, but the price is still way to high for the return at this time... I would be willing to pay 40% to 50% more but 5 times the cost still does not pay for its self at this time... Fingers crossed

lewster · 01-09-2015, 06:16 PM

Quote:

Originally Posted by kscherzi

Thanks for the update Lew. Out of curiosity how big are the lithiums? Are they a similar dimension to the group 24s or golf cart batteries?

The 100 amp/hour units that I have in the van are about the size of a GP-24.....maybe a bit smaller........but SERIOUSLY lighter. I'll measure them tomorrow.

ghaynes755 · 01-09-2015, 07:05 PM

Specs on the 100ah version at AMSolar.

12.8 Volts (Nominal)
100 Amp-Hour Capacity
9 & 11/16" (246mm) Long
5 & 5/8" (143mm) Wide
9 & 1/4" (235mm) to top of Bolt
Weighs 28 lbs.

Other configurations 200, 300 & 400 ah are shown on the site. Neat thing is that you can have a long skinny setup or a more square setup when you do the larger setups. Example the 300ah can be 5.625 x 29 or 7.25 x 22.5 or 11.25 x 11.5 inches.

And price appears to be just shy of 2x the price for a comparable setup at least for the 300ah Lithium vs 6 of the GPL-4CT Lifelines.

slowmover · 01-10-2015, 01:21 AM

So, 56lbs replaced 200lbs with the same performance? That's a hell of a ratio.

lewster · 01-10-2015, 05:29 AM

Quote:

Originally Posted by slowmover

So, 56lbs replaced 200lbs with the same performance? That's a hell of a ratio.

YEP!. Look at it this way: a 300 amp/hour Lifeline battery bank has a generally accepted usable capacity of 150 amp/hours (50% depth of discharge).

The 200 amp/hour lithium bank can be drawn to 80% depth of discharge, providing a capacity of 160 amp/hours.

Pretty interesting!

KJRitchie · 01-10-2015, 09:28 AM

Early adoption is expensive. Most RV owners don't care about battery weight when they own 3/4 and 1 ton trucks to pull larger RVs so prices will remain high as there will be little demand. Hopefully manufacturing costs will come down and other industries will adopt this technology so the RV industry can take advantage.

Kelvin

markdoane · 01-10-2015, 10:28 AM

Quote:

Originally Posted by KJRitchie

. . . Hopefully manufacturing costs will come down and other industries will adopt this technology so the RV industry can take advantage.

Kelvin

I wonder if any of these Lithium chemistries will be able to survive in the face of the Tesla/Panasonic Gigafactory being build near Reno?

I think they plan to use NCA chemistry, and optimize it until the cost/kWh gets down to around $100 per. If true, it may displace other (LiFeYPO4) chemistries just by brute force. Even if NCA batteries aren't optimumized for RV use due to different discharge characteristics, they may be better just by the fact that they will cost a lot less per kwh.

Who wouldn't pay $120 for a 100 ah Lithium NCA battery?

**Rocinante** · 01-10-2015, 10:56 AM

I love the idea of Lithium batteries for the improved amp hours per pound. What do we know about the fire safety of the YPO and NCA lithium cells? I remember the Boeing 787s that were grounded all over the world for a bit, and I'm well aware that my AS is anything but fireproof.

markdoane · 01-10-2015, 11:13 AM

At this point I think it's clear that YPO is safer than NCA. Like any evolving technology there are hurdles to overcome.
I think the safety issues will (and are) being addressed. It's been a year since a Model S Tesla caught fire, and the Boeing 787 is back in the air. I think the days when a backyard inventor can just strap a few batteries together and have a safe system might be over.

graysailor · 01-10-2015, 11:58 AM

Interesting thread. The cost is a little prohibitive at this time but may prove to be a break even giving the live expectancy of the lithiums. Having a special charger which is a must is another thing to deal with. Just a wait and see for me.

ghaynes755 · 01-10-2015, 01:03 PM

Just some information from my experience.

I've been using LiPo batteries for UAV's for the past few years (Different chemistry than the types being discussed, LiFeYPO4) and there have been rare instances of them catching on fire. And in all of them the reason was usually one of three reasons. 1. Battery was physically damaged in a UAV crash and should have been retired/destroyed. 2. Battery was discharged below 20% capacity, damaging the cells. 3. Battery was abused during the charging process.

With the rapid growth of personal UAV's like the Phantom I am actually surprised that we haven't heard about more instances of this happening due to user abuse.

All of these fall into the user error category. #1 isn't likely in our situation. #2 and 3 are addressed by using an 'approved' battery monitoring and charging setup.

As Lew mentions most lithium setups have electronics that will shut the cells down at 20% charge remaining. The chargers are 'special' in that they have the ability to closely monitor the charge cycle and 'balance' all of the cells to the same voltage which is very important to the life of the batteries.

An example is the charger that I use for 9ah 6 cell batteries made by RevoLectrix, a PowerLab 8. I can setup an exact charging cycle for this battery controlling the rate of charge and how it handles the cutoff cycle (similar to bulk, absorb, float of a Magnum). The charger is basically very similar to a Magnum charger and when hooked to a computer I can see all of the parameters so that I can log data about a specific battery to monitor its age, wear and tear characteristics.

mutcth · 01-10-2015, 01:53 PM

This is all fascinating stuff. I know on the Class B forums, everyone's aflutter about lithium, especially as it starts becoming standard equipment.

I'm excited because the next trailer I get will have a more serious solar system, and I don't want to give up too much space for the battery bank or too much weight...

Tom

IanPoulin · 01-10-2015, 03:44 PM

that's it! early adopter...

Jaxon · 01-12-2015, 06:07 PM

Quote:

Originally Posted by KJRitchie

Early adoption is expensive. Hopefully manufacturing costs will come down and other industries will adopt this technology so the RV industry can take advantage. Kelvin

Prevost has and so have several of the outfits that convert them into RV’s & tour busses.

Makes a significant reduction in weight and space when you switch to lithium batts. Or, keep those same factory weight specs (from the old AGM batts) and increase the number of lithium batteries for greater off-the-grid capabilitiy.

Whatever... Gomer sure knew how to sum it up...

https://www.youtube.com/watch?v=jSpBwt4hFN8

ronstory · 01-12-2015, 06:49 PM

One additional point about freezing the 'standard' LiFePO4 batteries... it takes a bit to freeze them. Typically they are rated a minimum usable temp of -4F (or -20C). I have one in my motorcycle and when it got to 24F in Porland recently, I got naturally curious (it's a disease

) and it started up the bike with zero hesitation.

My land rover TDI was very lethargic starting at those temps, even with a 3 month old Costco 800 CCA Lead acid battery.

Any idea what the usable temperature range will be for the new batteries?