Portable Powerbank

[eksine]

I appreciate your comments, but think that you don't fully grasp the the level of damage an NEMP can do to the semiconductors in a BMS, especially when they are connected to the lengthy, unshielded conductors found in almost all solar setups.

Tests that were run at Sandia in conjunction with the EMP Commission indicate that plain lead-acid batteries, with their negative terminals properly grounded, are unaffected by any foreseeable level of NEMP up to 50kv/meter unless connected to extremely long conductors (several hundreds of yards in length), or to the grid via a charger, and even then are quite resilient, with only minor damage occurring that didn't affect their capacity or further operation. As far as aI know, no LiPo4 batteries were tested, as this was some years ago before they were really on the scene; however, it's likely that the batteries themselves would be fairly resilient since they share a reasonably-similar architecture with other storage batteries, the major difference being their internal BMS and it's semiconductors that are extremely vulnerable to the E1 and E2 components of even a moderate NEMP event. If the internal and practically non-accessible BMS is destroyed, charging the battery becomes extremely problematic.

Everyone has to decide for themselves what risks they are willing to take with their alternative energy system; I've given my opinion here based on my years of real-world electronics experience, as well as the conclusions of the various NEMP study commissions over the past couple of decades and correspondence with their members, so I really have no more to say on the matter.

Wait, you fear an nuclear EMP attack. Let's pretend that that's a 100% probability. the battery systems would be the least of your worries. let's keep indulging in this though. BMS are generally designed and built in China except for some very expensive ones here in USA. they are cheap, you could carry spares. What did they say if the BMS is not connected though? can you have a spare(s) and just replace if needed? what I'm most confused about is that you are implying the BMS is NEEDED for you to charge the battery bank, it's not, it's just a protection device, it does prevent overcharging, overvoltage, overcurrent, etc. but in an emergency situation like you describe, remove the BMS and ASSUMING the solar charge controller still works than you just plug it up to the battery bank. in fact in emergencies , if you can verify what the solar panels are outputting or have a way to measure voltage with lets say an analog or other voltage meter you simply refer to the printed chart of lifep04 and stop at 100% state of charge (SOC). Dr. Jones I assure you there is always a way, never think because one way is closed that it becomes impossible. You are a doctor, you're smart as hell, just teach your mindset to be more mechanically inclined and find solutions. In solar there are many people that say something cannot be done, I assure you it's not the case usually.

They told me rebuilding a 5 speed automatic transmissions was a job ONLY for professionals, there's hundreds of parts in it that would be too daunting for many people. I proved them wrong when they said I was too stupid. not only did I disassemble every piece in the transaxle, I also found out the reason and found a solution on how to fix it. all honda transmissions and models around the 1999-2006 era had transmission problems, I found out why and how and made videos and articles explaining how to fix it. with no prior experience. I also did a few other things that are fairly hard. I mean you're a doctor, you know what I'm saying. Don't close the door because you or someone else thinks it's impossible, find a way, you can do it!

 

[Dr. Jones]

Wait, you fear an nuclear EMP attack. Let's pretend that that's a 100% probability. the battery systems would be the least of your worries. let's keep indulging in this though. BMS are generally designed and built in China except for some very expensive ones here in USA. they are cheap, you could carry spares. What did they say if the BMS is not connected though? can you have a spare(s) and just replace if needed? what I'm most confused about is that you are implying the BMS is NEEDED for you to charge the battery bank, it's not, it's just a protection device, it does prevent overcharging, overvoltage, overcurrent, etc. but in an emergency situation like you describe, remove the BMS and ASSUMING the solar charge controller still works than you just plug it up to the battery bank. in fact in emergencies , if you can verify what the solar panels are outputting or have a way to measure voltage with lets say an analog or other voltage meter you simply refer to the printed chart of lifep04 and stop at 100% state of charge (SOC). Dr. Jones I assure you there is always a way, never think because one way is closed that it becomes impossible. You are a doctor, you're smart as hell, just teach your mindset to be more mechanically inclined and find solutions. In solar there are many people that say something cannot be done, I assure you it's not the case usually.

They told me rebuilding a 5 speed automatic transmissions was a job ONLY for professionals, there's hundreds of parts in it that would be too daunting for many people. I proved them wrong when they said I was too stupid. not only did I disassemble every piece in the transaxle, I also found out the reason and found a solution on how to fix it. all honda transmissions and models around the 1999-2006 era had transmission problems, I found out why and how and made videos and articles explaining how to fix it. with no prior experience. I also did a few other things that are fairly hard. I mean you're a doctor, you know what I'm saying. Don't close the door because you or someone else thinks it's impossible, find a way, you can do it!

Oh, certainly, it can be done, but would most people who use those batteries have the technical ability to do so? LiPo4 chemistry demands very specific charging parameters, which if not met can lead greatly-diminished battery life, or worse. I do appreciate your passion for finding solutions, in any case!

I

 

[eksine]

Oh, certainly, it can be done, but would most people who use those batteries have the technical ability to do so? LiPo4 chemistry demands very specific charging parameters, which if not met can lead greatly-diminished battery life, or worse. I do appreciate your passion for finding solutions, in any case!

I

Sure, but just to let you know if you didn't already there is another chemistry that is rated and can survive outdoor below freezing temps, it is more durable than lifep04, it's called lithium titanate, look up the specs and capabilities on Aliexpress. some lifep04 batteries use it's own current to heat the battery so it will work in winter, titanate does not require it it's more robust. Also if you haven't heard they are developing solid state batteries, not sure about those but it's interesting that they are trying to make it happen, it'll be the next phase of battery development. Also lifep04 isn't as delicate as you think, I'm sure you can make a makeshift circuit to limit voltage for emergencies. but like I said just buy spare BMS, it's like $40-80 , some are even $13 on AliExpress. JBD is the brand you want, it's got a reputation for reliability and performance. Finding a fix for EMP can be done, even if you have to shield the whole thing with lead or other EMP resistant shielding. just research and test, don't give up. You could also build your own EMP device to test your setup

 

[Lips]

+

hey Poppy (or anyone else)
this unit does 45W input / 65W output (Type C)
with all the coupons is only $30

Have one in use right now

Amazon.com

Back on 35%
Get extra 15% with code CY7KL3FX at checkout...

Net $29.99 plus tax

 

[sgt253]

@Poppy: thanks for the heads up. That's a good deal for its size. I ordered one. Best.

 

[orbital]

+

another good INIU powerbank deal,

with both coupon and promo code, it comes out to $15 plus tax
..22.5W 20000mAh USB C (even if it's not exactly 20,000mAh, still a good deal)

Amazon.com

 

[Kestrel]

Thx for the heads-up orbital;

Along similar lines, I just picked up this $18 power bank:

Amazon.com

with the advantage of the four easily-removable button-top 18650's (only ~2500 mAh each tho)

I briefly tested the (emptied out) bank as a basic battery charger, by charging a single flat-top 18650 from my flashlight, and it charged fine albeit slowly.

So being an 18650 charger, power bank, and four removable/replaceable 18650's; seems like a flexible unit.

 

[Poppy]

+

another good INIU powerbank deal,

with both coupon and promo code, it comes out to $15 plus tax
..22.5W 20000mAh USB C (even if it's not exactly 20,000mAh, still a good deal)

Amazon.com

@orbital Why do I read your posts? I just bought another powerbank I don't really need.
Thanks. At least I'm prepared.

 

[roostre]

Along similar lines, I just picked up this $18 power bank:
Amazon.com

The following quote is from the Amazon five-star review for this charger from "Richie in the United States on November 18, 2023":

'... Being that the batteries are not only easily replaceable, they are wired in "parallel" so they all remain at the exact same voltage, whether recharging or while being depleted. ...'

If the above statement is accurate, there could be large and potentially dangerous currents between individual battery cells when they are inserted into the charger if they are not all at similar voltages as they would rapidly charge/discharge each other without some additional circuitry preventing this.

Before I purchase this charger, could someone familiar with the charger please verify if the positive and negative battery contacts for the slots in the charger are "directly wired in parallel" or if there is some type of electrical isolation between the battery slots that would prevent excessive currents between the individual battery cells and also if there is any low voltage cutoff protection circuitry to avoid over-discharging the batteries when used as a battery power bank instead of as a charger?

 

[Kestrel]

Having looked at mine (I bought two), I am assuming the charger is simply wired in parallel as described; and will follow procedures as safe as I can regarding same. For example, if I was using as a charger with broken-up sets, I would charge individually or better yet in a better-known quality charger. I bought a pair of these for emergency backups to my main supply, as I have relatively few 18650's - all of which are high quality protected cells.

The cells do appear to have protection circuits; if I post length measurements and a closeup pic of one of them, I would be happy if you were to weigh in with your opinion ?

 

[roostre]

I probably would not be able to provide any helpful information concerning the included batteries, but regarding the low voltage protection cutoff, my concern was if when using the charger as a power bank with un-protected battery cells in the charger, if it would stop charging an external device when the battery voltage of the batteries in the charger became too low in order to avoid over-discharging the batteries in the charger.

Also, if the charger's User Manual does not clarify if the battery slots are electrically isolated from each other (to safely allow inserting batteries with different voltages), an initial indication as to whether they actually are could be preliminarily determined (but may not be the final correct answer) by using the continuity "beep" function of a multimeter to check for continuity between the adjacent negative contact points and then again between adjacent positive contact points that touch the negative and positive ends of the batteries in the charger.

Be sure to only use the continuity "beep" function when there are no external power sources connected to the charger and when there are no batteries in the charger.

Most likely using the two leads from the multimeter to touch the negative contact points of two adjacent battery slots in the charger (with one lead to each different contact point) will produce a "beep" sound indicating continuity. This does not tell us much and just indicates there is a common "ground".

If there is also a "beep" sound indicating continuity when doing this on the positive contacts, then the battery slots are probably in a direct parallel connection and inserting battery cells with different voltages could create a potentially dangerous current whose magnitude would depend on the difference in voltage.

But if there is not any continuity, then the battery slots are most likely (but not guaranteed to be without further testing) adequately electrically isolated from each other which would be preferred and safer.

The following URL describes how XTAR accounts for this in their PB2SL:

PB2SL charge and discharge balancing technology | Candle Power Flashlight Forum

 

[Kestrel]

Thx; I suppose I could dig up my multimeter to verify.

 

[sim1tti]

With so many 18650 cells, I've been partial to the single bay chargers that can double as powerbanks. Just carry as many 18650 as needed. Scale up or down.

My first was the ThruNite U1 in 2015. Basic little thing. Worked dependably for a few years. Not very sophisticated though. @HKJ did a good review back then covering its shortcomings.

Tried a ThruNite C2, which looked cool and kept the battery enclosed, but could not charge small-draw devices. Wouldn't top off devices either. Bummer.

I had big hopes for the Klarus CH1X. Held an 18650, looked much like the C2, had 2A output and recognized low voltage devices, Unfortunately it died almost immediately.

After the failures I kept going back to that little yellow U1 until picking up a Fenix ARE-D1. Micro USB. Can charge a battery at 0.5A, 1A and 2A (manual selection). Does 2A output as a bank, and has a selectable output mode for low volt draws. I've never taken measurements, though can say it dependably charges an iPhone and a GPS watch both to 100%. This thing has been wonderful for the last several years.









But we're in the USB C era now, and unfortunately the new Fenix model (ARE-X1) is a step down from the ARE-D1. Smaller, lighter, and simpler without as many charging options and less power.

I'm going to give the Xtar SC1 Plus a shot, which has USB C input (but not output) and can charge a cell at 3A. I've read @TimMc 's review and though it looks fine I'm skeptical it'll match up to the ARE-D1. But it's inexpensive and I'm curious so why not try? I just wonder why it seems that Fenix did this right (in my view) but dropped the ball with USB C? Does anyone know of any other models in this space that I'm missing which could be better?



Edited for typos.

 

[TimMc]

With so many 18650 cells, I've been partial to the single bay chargers that can double as powerbanks. Just carry as many 18650 as needed. Scale up or down.

View attachment 57570My first was the ThruNite U1 in 2015. Basic little thing. Worked dependably for a few years. Not very sophisticated though. @HKJ did a good review back then covering its shortcomings.









View attachment 57571Tried a ThruNite C2, which looked cool and kept the battery enclosed, but could not charge small-draw devices. Wouldn't top off devices either. Bummer.











View attachment 57572I had big hopes for the Klarus CH1X. Held an 18650, looked much like the C2, had 2A output and recognized low voltage devices, Unfortunately it died almost immediately.










View attachment 57576After the failures I kept going back to that little yellow U1 until picking up a Fenix ARE-D1. Micro USB. Can charge a battery at 0.5A, 1A and 2A (manual selection). Does 2A output as a bank, and has a selectable output mode for low volt draws. I've never taken measurements, though can say it dependably charges an iPhone and a GPS watch both to 100%. This thing has been wonderful for the last several years.









But we're in the USB C era now, and unfortunately the new Fenix model (ARE-X1) is a step down from the ARE-D1. Smaller, lighter, and simpler without as many charging options and less power.


View attachment 57577I'm going to give the Xtar SC1 Plus a shot, which has USB C input (but not output) and can charge a cell at 3A. I've read @TimMc 's review and though it looks fine I'm skeptical it'll match up to the ARE-D1. But it's inexpensive and I'm curious so why not try? I just wonder why it seems that Fenix did this right (in my view) but dropped the ball with USB C? Does anyone know of any other models in this space that I'm missing which could be better?



Edited for typos.

Nitecore F1

 

[sim1tti]

Nitecore F1

Unfortunately discontinued a few years ago.

 

[sim1tti]

These are the two important features that set the ARE-D1 apart for me. Not familiar with another 1-bay charger+bank that has them. Highlighted from the manual.

 

[fulee9999]

Back on 35%
Get extra 15% with code CY7KL3FX at checkout...

Net $29.99 plus tax


View attachment 56052

View attachment 56053

oh wow, I've just bought this full price... never would've imagined to look here for a discount

it feels great thob in hand, hefty little unit, haven't been able to check the 100W output, but from the little I've read about this it's supposedly pretty great
one thing I haven't been able to verify, for some reason I keep thinking this is a lifepo based powerbank, but haven't found anything related to that, so probably it's a simple li-ion based one, but if anyone knows feel free to share

 

[Lips]

oh wow, I've just bought this full price... never would've imagined to look here for a discount

it feels great thob in hand, hefty little unit, haven't been able to check the 100W output, but from the little I've read about this it's supposedly pretty great
one thing I haven't been able to verify, for some reason I keep thinking this is a lifepo based powerbank, but haven't found anything related to that, so probably it's a simple li-ion based one, but if anyone knows feel free to share

I think it's lithium-polymer battery. Nice unit, bought two at $29. They run it on sale couple three times a year...





I'm watching this one below to go on 50% off Sale. I'll post it here when it hits!

At $109 the Ecoflow River 2 with 256wh is a great Lifepo4 solution for charging phones and such...
On sale now with 5 year warranty refurbished by Ecoflow...
30 days to send it back on their nickle also...

 

[orbital]

+

LiTime 12V 100Ah (1.2kWh) LFP battery can be had for $237 from a good company
use coupon clear5 at checkout.

Most people know, LFP batteries can be recharged thousands of times

Ampere Time 12 Volt 100Ah Deep Cycle LiFePO4 Lithium Battery

Ampere Time lithium batteries offer 100% usable capacity, a longer lifespan than lead acid, are lighter weight, and include complete protection from BMS. Flexible energy combinations up to 20.48KWh for RV, van, solar, and camping applications.

www.litime.com

 

[knucklegary]

+

LiTime 12V 100Ah (1.2kWh) LFP battery can be had for $237 from a good company
use coupon clear5 at checkout.

Most people know, LFP batteries can be recharged thousands of times

Ampere Time 12 Volt 100Ah Deep Cycle LiFePO4 Lithium Battery

Ampere Time lithium batteries offer 100% usable capacity, a longer lifespan than lead acid, are lighter weight, and include complete protection from BMS. Flexible energy combinations up to 20.48KWh for RV, van, solar, and camping applications.

www.litime.com

You'll need to get the charger too ?