Is BIG BATTERY full of Crap??

[Will Prowse]

Temperature Cycling Chambers | Environmental Test Chambers | Test Chambers | Thermal Chambers | Rapid Rate Thermal Cycling Chambers | Thermal Cycling Chambers | Temperature Cycling

The ThermalAir TA-5000 products with a wide range of temperature cycling capabilities. Bench top -40°C to +80°C applications to temperature cycling -100°C to +300°C environmental test. The TA-5000 is used for temperature testing in engineering product development test labs and production test...

www.mpi-corporation.com

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Liquid Nitrogen Dewars - Worthington Industries

Worthington’s liquid nitrogen dewars are designed for storing and dispensing smaller amounts of liquid nitrogen.

worthingtonindustries.com

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Those have got to be crazy expensive -20C will do haha

edit: just ordered Midea, which hits -28C. So we can easily trigger the charging protection sensor on the -20C packs.

 

[Deleted-User]

Those have got to be crazy expensive -20C will do haha

Or, visit a local cryo chamber...but I think they're even colder at around -200F. I'd buy one if I had crazy YT money.

 

[Deleted-User]

Costco is running a deal on Midea 7 cu.ft. for like $159...hope they have stock in LAS.

Hook up an Inkbird external 'PID' controller to this box, and dial in your chosen temp:

Amazon.com

 

[Hedges]

This is what I have:

Temptronic Corp Thermostream Temperature Forcing System TP0412A-2-60 | eBay

Model# TP0412A. Temptronic Corp. Air Temperature forcing unit. Wide temperature range: -70 degrees C to +205 degrees C, Temperature Accuracy +/-.5 degrees C. Everything is sold AS-IS. Sold AS-IS.

www.ebay.com

Cost more like $200, but isn't working yet ... needs one of the two-stage refrigeration units recharged.

Roast a turkey, then deep freeze it. ?

 

[DJSmiley]

I think you can get the Midea to reach lower temps. Just figure out the temperature sensor and modify it (either move it to outside the case or if its eg a PTC or NTC, maybe with a resistor changing its properties so it will think the temp hasn't been reached yet.
Or completely bypass its thermostat and power the compressor directly from an external thermostat

Don't know how low you actually can get it, but I think 5-10C more might be possible (for testing energy usage isn't huge of a concern, and ice buildup inside also not, since you can defrost it once testing is done before your next test

 

[Deleted-User]

Might be able to eek out another video on the topic of converting a Midea deep freeze into a vanlife solar fridge using the Inkbird...

 

[fat_old_sun]

I just need to buy a freezer and cycle them a few times. Then we will know.

My understanding is that lithium plating would show up in a capacity test result after a single cycle.

I will buy the coldest freezer I can find.

Be careful if/when you try charging at very low temps. Lithium plating often leads to the formation of dendrites which can puncture the separator & cause an internal short. Do it in an explosion proof freezer that is placed outside.

I wouldn't trust the datasheets claiming sub-zero charging at 0.1C. It's not too different from those Chinese outfits that sell PWM as MPPT. If all it takes to improve sales is a small lie, they'll do it. To my knowledge there are no lithium chemistry that takes well to sub-zero charging for reasons @Luthj explains.

 

[Hedges]

Be careful if/when you try charging at very low temps. Lithium plating often leads to the formation of dendrites which can puncture the separator & cause an internal short. Do it in an explosion proof freezer that is placed outside.

Exactly which cell is Will using?
I read the entire data sheet he linked. It described three chemistries they offer; some described as explody, some not.

But sure, extra precautions advisable. You never know if what you bought is what you got. And make sure the fire insurance is paid up on that nice workshop!

 

[fat_old_sun]

Exactly which cell is Will using?
I read the entire data sheet he linked. It described three chemistries they offer; some described as explody, some not.

But sure, extra precautions advisable. You never know if what you bought is what you got. And make sure the fire insurance is paid up on that nice workshop!

Lithium plating & dendrite formation can occur in all lithium cells under the right conditions. Certain lithium formulations are more prone to runaway reactions unrelated to plating/dendrites, Li-NMC being one. LFP & LTO are (relatively) safer.

 

[Luthj]

If the pack is LFP, then you don't really have much risk of explosion. My understanding is that a small separator failure (internal short). Doesn't result in thermal runaway, just a cell the self discharges and/or overheats.

That being said, a thermal even in an LFP cell often means vented electrolyte and vapor. So I would keep the freezer outdoors, or at least in a garage or something you can ventilate. The electrolyte is nasty...

 

[ghostwriter66]

I honest to God hate it when companies like BigBattery try to throw something out there that on the surface is technically correct BUT the way they are doing it is BULLSHIT. SOOOOO now we are going to have this damn conversation - again - for the second year running - about charging while below freezing ... YES you can do it - YES you can EASILY ruin your battery if you do it wrong -- YES you are charging at a barely minimal rate and NO these batteries will NOT recharge 100 or 50 or 20 or even 10% the next day ... SOOOO what pisses me off is that good people - these guys that live in the cold - in RV's and Tiny homes are going to run out and buy these batteries because BigBattery marketing department tried to get "cretive" in their advertising and the consumer now erroneously thinks that they can fully recharge their batteries below freezing to make it through the night and BB knowing that 99.99% of the ppl out there do not understand the difference between 2C and 0.1Ca ....

 

[ghostwriter66]

HEY while we are on the subject -- what was the BMS that @Will Prowse is saying is NOW his favourite BMS and may be coming out with BT? The BIG one thats in that battery box he took apart ?? THX

 

[Hedges]

or even 10% the next day ...

I read it as saying it could recharge 10% in the next hour. That should easily put in at least 50% during the day even if it didn't warm up.

As you said, the consumers aren't likely to understand.

The system needs to automatically address that. Does Big Battery's product at least automatically disconnect if charge current exceeds allowed maximum at that moment/temperature?

Ideally, the charge controller is somehow informed and adjusts its output. Either a datacom link (complex), or Big Battery ought to have a linear regulator that reduces voltage applied to the cells in order to reduce charge current to 0.1C. Whatever voltage drop and watts dissipate in the regulator ought to heat the batteries. Or, charge controller with temperature sensor, programmable for current limit vs. temperature.

 

[striider]

HEY while we are on the subject -- what was the BMS that @Will Prowse is saying is NOW his favourite BMS and may be coming out with BT? The BIG one thats in that battery box he took apart ?? THX

https://overkillsolar.com/product/bms-120a-4s-lifepo4/ SUPER beefy BUT I would be interested in less expensive alternatives that can handle a 206AH 12 volt system sufficiently. Better yet, one that could manage a 12volt 824 AH system in one unit?

WILL - love your videos, you have helped me realize what is possible with current battery tech. Glad we could come up with a new vid series idea for you. Eagerly awaiting results with your new freezer!

 

[fat_old_sun]

I honest to God hate it when companies like BigBattery ...

Not defending Big Battery, but they are *not* a R&D house. They're in the business of inventory turnover. However, if they prepared the datasheets without verifying the specs, it would be irresponsible (& may even be criminal). They're very likely repeating what their unscrupulous suppliers have told them. VW, Theranos and so many others have done it. It's ultimately the consumers responsibility to vet these claims - not an easy task.

 

[AussieSim]

So many reports on this forum about failed cells in new and used Bigbattery packs, with no recourse since they were past 30 days ! This would be illegal under Australian consumer law.

RETURN POLICY
BigBattery offers a 30-day warranty from delivery date on all of our products.
Item(s) must be new, unopened and show no signs of wear.
A 20% restocking fee will be charged for item(s) that are not defective.
Shipping fees are non refundable.
BigBattery is not responsible for shipping costs to return your item(s).
Item(s) must be sent back within 30 days of the delivery date.
BigBattery is not liable for any return packages that may become lost or stolen in-transit. Please keep proof of postage and/or return tracking number when shipping back your returns.
Returns are processed within 5-7 business days after your item(s) are delivered to us.
Damaged, defective, or incorrect item(s) must be reported within 7 days of delivery.

 

[Hedges]

So many reports on this forum about failed cells in new and used Bigbattery packs, with no recourse since they were past 30 days ! This would be illegal under Australian consumer law.

RETURN POLICY
BigBattery offers a 30-day warranty from delivery date on all of our products.
Item(s) must be new, unopened and show no signs of wear.
A 20% restocking fee will be charged for item(s) that are not defective.
Shipping fees are non refundable.
BigBattery is not responsible for shipping costs to return your item(s).
Item(s) must be sent back within 30 days of the delivery date.
BigBattery is not liable for any return packages that may become lost or stolen in-transit. Please keep proof of postage and/or return tracking number when shipping back your returns.
Returns are processed within 5-7 business days after your item(s) are delivered to us.
Damaged, defective, or incorrect item(s) must be reported within 7 days of delivery.

Saw that, but on front page:

"Ask us about our comprehensive 10 Year Warranty on our batteries & kits!"

Lithium Battery Packs | BigBattery | Your Source for Power

Big Battery offers the best Lithium-Ion powered batteries at the best cost and are applicable to solar, RV, golf carts, industrial machinery, and more!

bigbattery.com

Details of warranty ought to be posted.
A 30 day return policy (on unopened) products is different.

 

[Hedges]

I read it as saying it could recharge 10% in the next hour. That should easily put in at least 50% during the day even if it didn't warm up.

Just looking at the BigBattery page describing a battery:

12V 170Ah LiFePO4 Power Block – BigBattery.com

bigbattery.com

I see 100A charge current, and charging down to -20C
No mention of 0.1C limit at any temperature.

It does say BMS protection for temperature, over-current.
We hope, but don't know, that the protection implements current vs. temperature restrictions.

You'd be OK in an RV with 1 kW of PV and 10 kWh battery, or with a charge controller programmed to deliver no more than 1 kWh to battery but allow more PV power to reach inverter.

I didn't find any links on that page for more detailed data or instructions.

 

[Will Prowse]

I am going to freeze those cells to -20C, and charge at max rate. Repeat. Then capacity test, or test internal resistance with my cell monitor.

And I do not trust any company or distributor. @fat_old_sun is correct, and the only way to find out is to test it ourselves. Bigbattery has a qualified EE as head designer, and he knows his stuff. I am not sure where they found him, but he seems to know everything. I have thrown a lot of questions at him, and he always knows his stuff.

But yeah, lets test it!

 

[Picasso]

test a battleborns protection also......