Portable Power Banks

[Bill O]

Originally Posted by john61ct

Yes those little jumpstarters / portable powerpacks can be very valuable for those uses.

The OP was about expanding House bank style capacities, and the ones that are closer to being able to do that cost well over a grand, but share in the cost-benefit issues I outlined.

And at those prices, you would think replacement batteries would be available?

John,
In #4 above the OP indicated the main reason for the bank was to run peripherals at night and have more of a separate portable bank that could be easily recharged w/his excess solar. I was able to find an 18000 mAh bank for ~$85 US and would think that (or 2 of them) would be more than enough to run things.
Don't really understand how they are using 80Ah overnight especially if they are turning off equipment to conserve. This seems high to me, compared to our daily use.

Bill O.

[KTP]

Wait for the Trojan Trilliums to come out and then just slap a cheap pwm solar charger on the side of one. You then have a waterproof, bulletproof 1200 watt-hr power source with solar charging that is only 27 pounds.

[Bill O]

Originally Posted by KTP

Wait for the Trojan Trilliums to come out.

Supposedly they are out now, but could only find one source for them online.


Bill O.

[john61ct]

Then I misunderstood the OP's needs.

LFP is a **huge** improvement over other LI chemistries.

Originally Posted by Checkswrecks

The device I have contains 21 (LiFePo4s)

Do you mean 21 (of) some standard cylindrical cells like A123 ? I think about an Ah each?

Can they be swapped out without breaking the box?

If so I'd be very interested in **that**, would be a first afaik.

The downside with many of those internal BMS, they limit the charge rate current to stupid slow.

Really no reason at all these chemistries shouldn't be able to get refilled in a couple-few hours.

I completely agree the **concept** is a good one, just been so disappointed in the actual execution, and anything half decent is usually priced just crazy on a per-Wh basis.

And it still takes a fair bit of grokking to match up a given use case with the actual specs of the various components, lots of vendors in this markey niche are flat out liars and scammers.

I really have to say I'm very gratefully surprised that stupid "generator" marketing double-talk hasn't come up. 8-)

[john61ct]

Originally Posted by Bill O

18000 mAh bank for ~$85 US

Link?

[Bill O]

Originally Posted by john61ct

Link?

Looked at too many, sorry it's only $69.99!
https://www.amazon.com/GOOLOO-18000m...TAD9JW6KJKJ5ZD



Bill O.

[mat jam]

Thanks to the many forum members for answering my query.

To clarify, I want to make use of available energy going to waste after my batteries are full. I want a separate energy source for a number of reasons - back up, portability, night use and to avoid adding more gear such as more batteries, wind gen, etc. Adding another panel is easy with my setup and will allow faster charge time. I was expecting about 2 evenings use ability but it appears it is longer dependent on the size.

My main concern was the reliability (longevity over time) and uses. It appears from the comments that they are reliable and would be practical for my intended use. The only thing is from my search, most of the units are geared towards 120v (N.A market) and there does not appear to be much selection for the 220v (EU market) available.

[john61ct]

In order to get decent energy in suboptimal conditions, you will always have a surplus when insolation is strong.

Don't look at it as wasted, the only way to put it to use is a load that you don't really need.

Pre-warming your HWS for example, sure now the energy does something useful, but the value of the propane (or whatever) it saves will not pay back in 100 years the cost and effort of capturing that little bit of excess power produced.

[Bill O]

Mat jam,
Thanks again for the clarification of the 220V bank. You are correct, there are not as many 220V banks and the one I did see were much more expensive.
Did see

this

as a potentially viable way to make a 220V bank if you needed. Liked the inverter they used but not the 12V FLA battery. The FLA would work but instead swap out the battery w/the 18000 mAh power bank I linked before.(??)
Don't know exactly what items you need to recharge, but do you really need 220V if you are charging tablets, phones, etc. or would the USB plugs work?


Bill O.

[john61ct]

If you're bothering to build one yourself, put in a 30-60Ah battery, or maybe even 100Ah

LFP is a third the weight and size of the lead equivalent.

And note the powerpaks are likely giving Ah using the internal voltage of a single cell, say 3.6V for marketeering purposes whereas the standard should be @12V.

So 18000mAh really = 4.5Ah compared to above

Or just use Wh for apples to apples, same capacity no matter the voltage used.

[Bill O]

Originally Posted by john61ct

If you're bothering to build one yourself, put in a 30-60Ah battery, or maybe even 100Ah

LFP is a third the weight and size of the lead equivalent.

And note the powerpaks are likely giving Ah using the internal voltage of a single cell, say 3.6V for marketeering purposes whereas the standard should be @12V.

So 18000mAh really = 4.5Ah compared to above

Or just use Wh for apples to apples, same capacity no matter the voltage used.

John,
Can't disagree with the above except not everyone wants to plunk down the huge amount of money for LFP technology. I personally am waiting for the magnesium based batteries to emerge to then reduce the LFPs to a reasonable price range.

Back to the OP's question/issue. No matter how you look at it you will be adding more "gear". We have a wind gen and will say the solar on average will out perform the wind gen in low wind areas. Seems like you have plenty of solar, so check that one off.
Without knowing exactly what you need to power/recharge, its difficult to offer viable solutions. Our power banks are able to recharge our devices in the cockpit, then the bank(s) can be recharged using 12V as needed.
If you really need 220V (and you already have those inverters installed), John's idea of expanding the house bank seems the most reasonable and cost efficient (if you have room for another battery). This also makes the recharge from the solar almost automatic and you will never forget to plug in/recharge a portable.


Bill O.

[mat jam]

Bill O,

Thanks for the video link.

It is more practical to go with 220v as most of the world runs on 220/230 as do my systems. This also gives the option of a fast charge via outlet. I also have some small appliances I believe would work. It is really about back-ups /redundancies i.e. I can currently boil water three ways - gas, inverter, and GoSun and this would add a fourth option. I also like the portability.

I would be interested to hear you thoughts on the wind gen as this is most likely an eventuality as the best source for keeping me powered at night.

[john61ct]

The profitability of this whole market segment is driven by people trying to avoid figuring out these electrickery details.

But real utility and value will only come after you do.

The voltage of the AC output is just a matter of the right inverter.

The main function of these power packs is energy storage. Whether bought OTS or built DIY, key questions to answer are:

Actual Wh capacity of the batt inside?

How fast a Watts rate allowed flowing in charging, how much out to loads?

What chemistry, expected lifetime cycles?

Replacement battery availability and cost so you don't need to toss the whole thing out?

Once you have good answers to these, you will have a clear idea of what sorts of loads you can power and for how long.

To the extent the unit is very portable,

inherently small and light means low capacity,

you should really be avoiding devices designed for mains anyway, look for 12V versions, likely much lower overall consumption of watts.

Especially if the load device runs off DC internally or has its own battery, it's just silly to use an AC powered DC charger off an inverter powered by a DC source.

A suitable inverter may well only cost the price of one nice meal out, should really have little bearing which portable battery-in-a-box you buy.

[Peeew]

Are you thinking of 100 amp hours available by using batteries from 100% down to 50%? I am finding it difficult to get batteries above 80% using solar and some diesel gen/engine time. Above the bulk charge it takes many hours to reach the final 80-100% full. I would count on 30% usable daily.

[john61ct]

At least for the non-lead battery chemistries we're talking about here, should be able to draw down much deeper, get 80% of capacity usage each cycle.

And fully recharge in under 2 hours.

That is what you pay the premium per-wH price for, also portability, higher energy density, lighter and smaller per-wH as well.