Ultra-Capacity Lithium Batteries

There are at least three companies putting out yuge capacity lithium batteries. Would you ever consider one if your electric needs were minimal?

Anker Powerhouse 2
https://www.anker.com/deals/powerhouse2

Goal Zero Yeti 400
http://www.goalzero.com/p/423/goal-zero-yeti-400-lithium-portable-power-station

Eco Flow Tech River (crowdfunding)
http://ecoflowtech.com/

IMO tiny capacity, super expensive per AH.

But portable and fashionable design.

Not really anything to do with van living, more for regular people to recharge gadgets on a day out.

the capacity is about 1/10th what the average vanner is using. I can get you a lithium battery from shorai of the same capacity for $100 shipped.

The Anker linked product is 434 W/H
434 divided by 12.2v =35.58 AH capacity
434 divided by 5v (USB voltage) = 86.8Ah capacity
Huge capacity?
How much does it cost?
Here's 70Ah of lead acid AGM for 120$
https://www.amazon.com/UPG-UB12350-...=UTF8&qid=1492839471&sr=8-2&keywords=35Ah+agm

There is a lot of competition in the combined inverter/controller battery market.  Jackery had a kickstarter as well.

Suaoki had a 40ish amp hour model, no longer available.  Presumably either for quality or supply issues.  Here's the 20 ah model:

Suaoki 20aH (18.3?)

The Goal Zero, at 33ah for $370 (usable 30ah?) works for my needs but is still too expensive.

Power math can be weird.  Here in 12v world we are used to using amp hours as a consistent measure, but not so on devices as the assumed voltage can vary widely.  Unless I am getting my math wrong the Suaoki is using an assumed 11 volts???  Watt hours may be becoming the new normal.

No, the "fancy" vendors don't want to quote AH because it exposes just how expensive their packaged solution is compared to DIY.

If the small inverter and charger were enough for me, I like the ArkPak 730 concept, use whatever G31 you prefer.

I would pair it with a $500 Firefly Oasis, you could use a cheapo "marine" from Wally's, or go all the way up to a drop-in LiFePO4 like Battle Born.

But expensive, unless you really need the portability.

DLTooley said:

 Watt hours may be becoming the new normal.

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Actually, watt hours is the "old normal" because it is a mathematically accurate description of battery capacity across any voltage platform. Amp Hours seems to only have direct application in a 12v system. 

For example, my 6v L16 battery has 435 Ah. Two of them to equal 12v is still 435 Ah. I have 4 of them to equal 24v...still 435 AH, which really doesn't do me any good in trying to understand how much capacity I actually have. Instead, knowing that I have 10,440 watt hours allows me to calculate how much my appliances will drain my capacity.

10.4 kwh is pretty big. I less than 1 kwh per day.

John61CT said:

No, the "fancy" vendors don't want to quote AH because it exposes just how expensive their packaged solution is compared to DIY.

If the small inverter and charger were enough for me, I like the ArkPak 730 concept, use whatever G31 you prefer.

I would pair it with a $500 Firefly Oasis, you could use a cheapo "marine" from Wally's, or go all the way up to a drop-in LiFePO4 like Battle Born.

But expensive, unless you really need the portability.

Click to expand...

I've got 5 years on my wally world, plus one of these:

https://www.amazon.com/MinnKota-Tro...3171422&sr=8-1&keywords=minn+kota+battery+box

(my 2nd wally world actually, killed the first under warranty)

The 33 ah would cover my load, and yeah, I'm looking for a solution I can carry in a canoe for overnights.

A 1500 watt inverter is on my wishlist, enough to run one power tool.

For a canoe, LFP saves half the weight.Cells alone maybe $200, but have to spend more on the support infrastructure. Maybe a couple of light Pelican style boxes better than one big one. . .

There seems to be a general misunderstanding of the term amp hour when comparing batteries. Where is Stern Wake

Watt hours (WH) accounts for the dropping voltage of a battery as it discharges and is a more accurate reflection of electrical consumption than amp hours.

But amp hours (AH) is a standard that lead acid battery capacity is measured in.

Which is kind of asinine as a 100 amp hour battery can produce 5 amps for 20 hours, but getting a 5 amp load at 12.8v and having that same load draw exactly 5 amps at 10.6v requires specific equipment, making a home brew 20 hour capacity test, nearly impossible to be done accurately. The batteries would also have to be held at exactly 77f degrees fo the duration of the test.

For our lead acid batteries, the 20 hour capacity test is really the only relevant measure of battery capacity remaining. Trying to do a 10 hour test at the 20 hour load( divide battery capacity by 20) is only useful, when one did the test when new and is comparing the aged battery to that first test.

For example 50% is widely believed to be 12.2 volts rested. if one were to put a 5 amp load for 10 hours on a fully charged healthy 100Ah battery, then remove the load at 10 hours, the battery should be 12.2 volts when voltage rebounds. But this half capacity test does not work well. Often the battery will rebound to a much higher voltage than 12.2v, and one will say gee my battery has more capacity than the label indicates.

If they were to continue the test for the 10 more hours for the full 20 it is likely the battery would fall below 10.5v at hour 18 or something, indicating the 100Ah battery has declined in capacity. The decline in voltage is not linear as a battery discharges. 12.2v is a general 50% state of charge area and not relevant on each and every 12v battery

A true 20 hour capacity test requires one hold the exact load for the full 20 hours, or hope it can power it for the full 20 hours before voltage falls to 10.5v. A 100% discharge is hard on a battery, and achieving the exact load as the voltage drops is difficult as well.

Now, I have an AH counting battery monitor. I have a 90Ah AGM battery with ~525 deep cycles on it. If I take 45AH from it, at a average 4.5 amp rate, then remove all loads, the battery should be at 12.11volts( as per Northstar), yet when I pull the battery quickly down 45AH at a 7.5 average amp rate( which should reduce total battery capacity per Peukerts law) then remove all loads, battery voltage can rebound to 12.35v.

So voltage alone is not a good indicator of state of charge. my 50% tests would indicate my 90Ah battery is more like 115AH capacity after 500 deep cycles and a few hundred more shallow cycles over 3.6 years, and no way would a battery manufacturer underrate their battery capacity and no way does my 90AH battery have well over 100AH, not at 3.5 years of age and 500+ deep cycles on it. Still its performance is impressive, but that is a testament to a good battery worked hard but recharged properly, often.

Just beware of product marketing lies deceit and trickery.
Capacity for powerpacks for USB devices are calculated at 5 volts. and frequently trick the consumer into thinking the battery has much more capacity than physics deems possible.

The Lithium battery jumpstarters frequently have people believing they are the alpha and omega super battery because such a small battery can jumpstart an engine. Truth is they have very small capacity but very high cranking amps, and truth be known, most vehicles could be started easily on a battery 1/10 the size as that which it comes with. starting Batteries are as big as they are for overhead, cold weather and for still being able to start a motor when its capacity has shriveled to a small fraction of that when new.

Beware of marketing. Beware of anything with 'ultra' in the description. The goal is to separate you from your money, and there is no truth in advertising, only deceit.

SternWake said:

no way would a battery manufacturer underrate their battery capacity and no way does my 90AH battery have well over 100AH, not at 3.5 years of age and 500+ deep cycles on it.

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Just FYI it is routine for LiFePO4 cells, at least at the large & quality side of the market, to actually deliver 10-15% higher AH capacity when new than their labelled rating.

I think this is due to higher variability in output, and the better sellers try to sell "matched sets" for greater ease/stability in keeping banks balanced.

Definitely a good idea to avoid surprises, to get some sort of benchmarking done at installation, to compare to as capacity declines over time.

Jackery has a new one out that is very nice.

https://www.amazon.com/dp/B06XJ1SVPW

maybe 40AH @12V but I doubt it, all the original comments apply

I wouldn't call any of the 3 "ultra capacity". They all have something like a 35 ah 3s 11.1 volt battery pack inside. Even the "jackery unit" that says its a 140,000 mah (140 ah?), its too small to fit that many batteries inside it, it states 500 wh, which is about 40ah maybe. Hard to say with these units.

The smallest lithium I have is a 3s 11.1 volt 33 ah battery pack. Even though it's small, it is usable for my limited needs. I use it to run my swampcooler and lights and also an inverter to power my netbook. It easily does that till around 11 pm. The next day it requires about 16 amps to top it off. The 11.1 volts is no problem to run my inverters. I been using it as a house battery for the past 3 weeks, and it does the job very well.

The only problem with these battery packs is the long charge times, even with the wall socket it takes 6 + hours. They have to slow charge them for safety reasons, since it relies on the built-in BMS to do the balancing and the BMS don't balance well at high charge rates. 
One thing about lithiums they are quite capable to be quickly charged with the right methods. On mine (that I built) I bought a balance charger (14 amps max output) and I can charge it at that rate. As long as it is in balance it will charge quickly at that rate, If its out of balance it will take longer, at the end of the charge it will reduce the amps to balance the battery. I always check on it while its charging and even when its almost full, the charger is still pumping in maximum amps.

From my own experience you can take them down all the way until the BMS cuts off the power, and do it all the time without damaging the battery. You also don't need to fully charge them. They are real "deep cycle" and "maintenance free". As long as you charge them correctly and don't hammer nails into them, they can be as safe as lead acid. The ones that catch on fire most likely went out of balance, over heated, melted the wires, which shorted out, causing sparks which then catch something on fire.

My kinetik 102 ah agm, didnt survive me taking it below 11 volts 3 or 4 times. And with solar I could never give it the high amps it wanted. Thats what made me switch to the lithiums. I still have the kinitek connected to the solar panel and use it to run my balance charger to charge the lithiums, thats all its good for. Without solar it don't hold a charge long.

This is what the inside of one of those battery packs looks like, they use the li-ion 18650 cells connected in 3 rows. 

When lithium ion batteries are usually a few thousand mAh, having large ones that are 140,000 mAh sorta fits the ultra capacity naming. Amp hour capacity means nothing across multiple voltages. This latest battery at 140,000 mAh is similar to a 86 amp hour lead acid battery in usable capacity.

140 amp hour at 3.7 volts = 518 watt hours = about 43 usable amp hours lead acid 12 volt car battery x 2 = 86 total amp hours (can only discharge 50%)

https://www.kickstarter.com/projects/67854833/jackery-power-pro-solar-ready-mobile-energy-soluti

True specs here...my math is wrong.

Yes AH or mAH are useless for these multi-voltage gizmos.

watt-hours is more accurate, volts don't matter

But I don't believe them anyway, for sure they're not using a proper 20-hour load discharge rate to be able to compare to usual deep-cycle standards.

Basic rule of thumb, if it's easy to carry around, it's good only for miniscule loads like screen gadgets, not even a full 8-hour day of cooling fans or laptop use.

If you want a bank that will run a little fridge 24x7, then you need a strong guy to hoist the batt(s) into your rig, even for LFP at half the weight of lead.

A DIY box, with a known good and easily replaced battery, is the only way to get good value in something portable.

ArkPak 730 + Battle Born G31 LFP for them that can afford it, and still need a better mains charger.

SternWake said:

Just beware of product marketing lies deceit and trickery.

Click to expand...

For sure in this (portable power packs) market.

SternWake said:

Capacity for powerpacks for USB devices are calculated at 5 volts.

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I think often at 3.x volts, or they just pull numbers out of their donkey.

Personally I would never buy such a device without first confirming the battery is easily replaced, non-proprietary, reasonably priced and readily available. Confirming, as in getting at least a couple "buy here" links.

Ebay vendors are often more forthcoming with that sort of information than others. Look for sellers that specialize in related goods, and start with the overpriced ones.