Charging MacBook with battery packs

[objektør]

Did a clean install but no charging from the Anker E5 or the 12V car charger.
I might just try the RavPower pb058 when I am in the EU (they don't send to Norway) next month and see if it works. If not I'll go for the RavPower pb 054 (the one with the power outlet). That one should do the trick with my rMB power brick.

@Mike Boreham:I did not manage to reverse the power flow from the rMB. It is still charging the 12V battery in stead of being charged. But you were right about the Anker E5. It is not charged by the rMB.

 

[objektør]

The need to reverse the flow has been necessary a number of times, not just the first. The button sometimes needs to pressed a few times to get the change of flow to "stick".
RavPower have replied to my email saying this is quite normal, but didn't answer my question about a proper manual or any mention of it in the leaflet supplied with it....but they "got my concern"!
[doublepost=1489302844][/doublepost]

Could you give us another update now that you have used the the RavPower for some time in real life.
Do you still have to reverse the flow sometimes? How many times can you approximately charge the rMB out of a fully charged Rav?
Any hiccups?
Thanks

 

[Mike Boreham]

Could you give us another update now that you have used the the RavPower for some time in real life.
Do you still have to reverse the flow sometimes? How many times can you approximately charge the rMB out of a fully charged Rav?
Any hiccups?
Thanks

I have been waiting to receive my Satechi USB-C power meter before doing a series of recharges of the Macbook. (Unsurprisingly with all confusion about USB-C they have been on backorder). With the meter I can measure the actual mAh delivered and the charging rate. I have received the despatch notification so should have it soon.

I haven't used the RavPower much due to circumstances, so I haven't anything to add to what I said before. It sometimes needs reversing, but I haven't noticed any pattern as to when it does or doesn't. Maybe it depends on the relative charge of the battery and MacBook (will look for this).

 

[objektør]

I have been waiting to receive my Satechi USB-C power meter before doing a series of recharges of the Macbook. (Unsurprisingly with all confusion about USB-C they have been on backorder). With the meter I can measure the actual mAh delivered and the charging rate. I have received the despatch notification so should have it soon.

I haven't used the RavPower much due to circumstances, so I haven't anything to add to what I said before. It sometimes needs reversing, but I haven't noticed any pattern as to when it does or doesn't. Maybe it depends on the relative charge of the battery and MacBook (will look for this).

Well, take your time I would say.
I got myself a cheap adapter (micro usb- usb c) that I used with the car charger. This works to charge the rMB but it depends on which way I put the usb c in the rMB. It shouldn't make any difference but it obviously does. Maybe because it is a cheap nonApple adapter.
Anyway I'm pleased I got it to work one way or the other and feel more secure now that the RavPower will work as well for me. I plan to order when I will be in the EU next month.

 

[Mike Boreham]

OK done some more testing, which is disappointing and surprising.


Starting point:- Fully charged RavPower and completely flat Macbook (it had shut down due low battery)

What I did:

1. Connected RavPower to Macbook with USB-C to USB-C cable meeting USB-PD spec, via Satechi USB-C power meter.
2. RavPower would not charge the MacBook. For a few seconds the MacBook would charge the RavPower (i.e. wrong direction) until the MacBook ran out of juice. This was indicated by the arrow on the Satechi indicating direction of flow and the lights on the RavPower flashing consistent with being charged.
3. Tried several times to reverse the flow (pressing and holding the button on the RavPower). Tried different USB-C (PD) cable. Tried without the Satechi meter in line. Would not reverse.
4. Connected RavPower to MacBook with a USB-A to USB-C cable and it started charging the MacBook correctly but only at 5V of course. I only did this for a few minutes to check it would work.
5. Then I discharged the Macbook to shutdown again and repeated step 1. This time it immediately started charging the MacBook correctly in USB-PD mode 30W, 15V 2A.
6. After 3 hrs the MacBook reported 100% charge and the charge rate had dropped to 0.02A. At this point the Satechi said it had delivered 4390 mAh. This is not apparently consistent with the max capacity of my MacBook reported by Coconut as 4969 mAh, but maybe the MacBook shuts down with 4969-4390= 579 mAh remaining…..quite likely.
7. Disappointingly, at this stage the RavPower only showed one flashing light out of four, ie nearly flat. This is not consistent with the total measured output from the battery of 15056 mAh I measured earlier with USB-A charging in the table above. Maybe the output is much less if supplying at 15V by USB-PD than at 5V by USB-A.
8. Then I used the MacBook normally to discharge it for another recharge, without doing anything to the RavPower.
9. I reconnected the RavPower when the MacBook had got down to 7%, but whatever I did it again would not charge the MacBook, as in 2. above. The flow would not reverse. It would still charge by USB-A, and I let it do this for a while, before trying USB-PD again, but it still wouldn't reverse when connected USB-C.
10. I reconnected by USB-A and let it carry on charging at 5V. The RavPower was able to charge the MacBook from 7% to 11% before it was fully discharged. I wasn't able to record the mAh of this period because after the battery was exhausted the Satechi shuts down and no value shown, but obviously the amount was not significant.
11. At the conclusion the MacBook had been fully charged by USB-PD from flat once. The RavPower had only delivered about 4390 mAh in USB-PD mode, plus a small amount more while in USB-A mode.

So very disappointing on two counts:


The problems of reversing the flow. I suspect that the reason it wouldn't charge by USB-PD on the second cycle was because the battery was nearly flat already. Maybe the battery needs to be well charged up to work at USB-PD rate. This doesn't explain the difficulty I had initially when the battery was fully charged. In previous more casual use it had never failed to reverse when necessary, although sometimes after a couple of attempts. I will check this when the RavPower is fully charged again. Update...yes it charged with USB-PD straightaway when fully charged.


The apparently much reduced output when charging by USB-PD at 15V. I don't know enough about battery technology to say whether charging at 15V would give a much lower transfer efficiency than at 5V, but it would not surprise me at all if it were true.

I haven't yet repeated this whole exercise with 5V charging to see if it would charge the MacBook as many times as the numbers suggest. Measured total output at 5V was 15056 mAh (from my table above), compared to 4390 mAh to charge the MacBook from flat. This would mean the RavPower should give three full charges at 5V with a bit left over.

Maybe these are the reasons that Anker withdrew their comparable USB-PD product after such a short time on the market.

This all reinforces my feeling that battery packs do not “do what they say on the box” and that USB-PD battery technology is very immature at this point.

I am within my return period and wondering whether to keep it for what it can do, or return it because of what it can't.

 

[Mike Boreham]

I am within my return period and wondering whether to keep it for what it can do, or return it because of what it can't.

Today the glass is half full not half empty, and I have decided to keep the RavPower.

Factors:

1. In USB-PD mode (15V), most times it charges correctly without needing reverse. It seems reverse can be flaky but eventually works if battery is fully charged.

2. In USB-PD mode it can fully charge a completely flat MacBook in three hours, but only once.

3. USB-A mode (5V) is completely reliable so always an option to USB-PD if charging speed is not an issue or reverse is misbehaving, or you want to maximise the output from the battery, probably 2-3 cycles to be confirmed.

4. Compared to the Anker Powercore+ (which also have) it has more capacity, more port options, same weight, but adds USB-PD capability.

Going to carry on testing, quantifying USB-A times and capacities, and repeating USB-PD results.

 

[Mike Boreham]

Today the glass is half full not half empty, and I have decided to keep the RavPower.

Factors:

1. In USB-PD mode (15V), most times it charges correctly without needing reverse. It seems reverse can be flaky but eventually works if battery is fully charged.

2. In USB-PD mode it can fully charge a completely flat MacBook in three hours, but only once.

3. USB-A mode (5V) is completely reliable so always an option to USB-PD if charging speed is not an issue or reverse is misbehaving, or you want to maximise the output from the battery, probably 2-3 cycles to be confirmed.

4. Compared to the Anker Powercore+ (which also have) it has more capacity, more port options, same weight, but adds USB-PD capability.

Going to carry on testing, quantifying USB-A times and capacities, and repeating USB-PD results.

RavPower Support have confirmed that it will only charge a MacBook once in USB-PD mode. They have also said that the button needs to be pushed for 8 seconds to reverse the flow. Not sure I tried for as long as that. Would be nice if there was any mention at all in the 'manual' about the need to reverse the flow or how to do it!

 

[objektør]

Today the glass is half full not half empty, and I have decided to keep the RavPower.

Factors:

1. In USB-PD mode (15V), most times it charges correctly without needing reverse. It seems reverse can be flaky but eventually works if battery is fully charged.

2. In USB-PD mode it can fully charge a completely flat MacBook in three hours, but only once.

3. USB-A mode (5V) is completely reliable so always an option to USB-PD if charging speed is not an issue or reverse is misbehaving, or you want to maximise the output from the battery, probably 2-3 cycles to be confirmed.

4. Compared to the Anker Powercore+ (which also have) it has more capacity, more port options, same weight, but adds USB-PD capability.

Going to carry on testing, quantifying USB-A times and capacities, and repeating USB-PD results.

Thanks for all the testing.
I din't expect much more than one full charge for the rMB anyway. It fits my needs.
Somewhere on their website I read it will charge the Macbook 1.3 times using usb-c PD. And as you have mentioned before they promise always more than they deliver.
It will be interesting what you'll find out about regular usb charging.
How fast did you manage to recharge the Rav. 3-4 hours as they promise?

 

[objektør]

My intention is not to use the Rav for charging a flat rMB but to keep a fully loaded rMB fully loaded and thus save the battery life of the rMB for when I need it. I am around 80% batteryhealth now after 460 cycles in 23 months. I try to avoid a new rMB battery (because there is no Applestore where I live and I save 200€)
Does it work for this purpose?

 

[Mike Boreham]

Thanks for all the testing.
I din't expect much more than one full charge for the rMB anyway. It fits my needs.
Somewhere on their website I read it will charge the Macbook 1.3 times using usb-c PD. And as you have mentioned before they promise always more than they deliver.
It will be interesting what you'll find out about regular usb charging.
How fast did you manage to recharge the Rav. 3-4 hours as they promise?

Regular USB charging (5V) is not much better! The fully charged RavPower charged the MacBook from 10-100%, then from 10-61% before being fully discharged. So about 1.5 charge cycles.

What is very surprising is that the USB power meter said it had delivered a total of 15227 mAh while doing this. (10130 mAh for the 10-100% and 5097 mAh for the 10-61%). This is consistent with the previous USB-A total delivery, but doesn't fit with my MacBook capacity of 4879 mAh (89% health) from Coconut. Part of the explanation is the RavPower is supplying what the Macbook is actually using as well as recharging, but for much of the 4h30m (10-100%) and 2h20m (10-61%) it was actually shut down. It is also inconsistent with the USB-PD charge cycle where the RavPower delivered 4390 mAh doing the full 0-100% charge.

I am inclined to trust the USB power meters which agree with each other within a few percent and produce credible results in other testing.

I haven't done the same tests carefully with the 20100 mAh Anker Powercore+ but what I have done suggests it behaves similarly (but of course does not have USB-PD).

I haven't tried your intended top-up mode, which should work with either USB-PD or USB-A mode, but I don't think you are going to get anything like the extension of use that you might expect from a nominal "26800" mAh battery. Depending on how often you need to reconnect the battery you might be better doing this in USB-A mode to avoid reverse flow problems in USB-PD mode.

The RavPower did recharge from flat in about 3-4 hours in USB-PD mode from memory but I didn't time it, so will repeat that today. I will also repeat all I have done and for the Anker Powercore+.

Main conclusions so far:

1. The RavPower will charge the MacBook once from flat in USB-PD (15V) mode
2. The RavPower will charge the MacBook 1.5 x from 10% in USB-A (5V) mode
3. Reverse flow is sometimes an issue in USB-PD mode.
4. The apparent shortfall to expectations is probably similar for the Anker and RavPower.

There is obviously more to this battery business than I understand! The transfer efficiency is obviously a huge factor and probably varies depending on the voltage and charge rate, and state of the donor and receiving batteries, and other factors.

 

[objektør]

Regular USB charging (5V) is not much better! The fully charged RavPower charged the MacBook from 10-100%, then from 10-61% before being fully discharged. So about 1.5 charge cycles.


I haven't tried your intended top-up mode, which should work with either USB-PD or USB-A mode, but I don't think you are going to get anything like the extension of use that you might expect from a nominal "26800" mAh battery. Depending on how often you need to reconnect the battery you might be better doing this in USB-A mode to avoid reverse flow problems in USB-PD mode.

Thanks again for all the measuring. It gives a fairly good idea how good (or bad) these batteries work at the moment.
It is doubtful how well they will keep my rMB topped up. Usb-PD mode could be troublesome because of the flow direction and usb-A mode didn't deliver enough when my Anker E5 still worked. (the rMB doesn't accept the charge anymore for some odd reason).

I got myself a cheap used solar panel as a supplement to the windgenerator. This will get me through the summer (it doesn't get dark here at night from april to august). I can keep the inverter on and use the regular macbook charger most of the time.

The battery packs with PD will improve over time I hope and capacities only get bigger and bigger. The RavPower with AC outlet is an option but I find the price too steep at the moment. Much can happen in a half years time.

 

[Mike Boreham]

Thanks again for all the measuring. It gives a fairly good idea how good (or bad) these batteries work at the moment.
It is doubtful how well they will keep my rMB topped up. Usb-PD mode could be troublesome because of the flow direction and usb-A mode didn't deliver enough when my Anker E5 still worked. (the rMB doesn't accept the charge anymore for some odd reason).

I got myself a cheap used solar panel as a supplement to the windgenerator. This will get me through the summer (it doesn't get dark here at night from april to august). I can keep the inverter on and use the regular macbook charger most of the time.

The battery packs with PD will improve over time I hope and capacities only get bigger and bigger. The RavPower with AC outlet is an option but the I find the price too steep at the moment. Much can happen in a half years time.

I understand your decision! The USB-C (PD) technology is very immature and as you say, I expect in a few months there will other products, or none if it turns out USB-PD is not really suitable for batteries. There has to be a reason why there have only been two USB-PD batteries on the market, and one has been withdrawn.

Out of interest I am currently using my MacBook in the top up mode your were considering. As you said USB-A charging barely keeps up with the normal usage, although it does slowly charge the MacBook while in use. USB-PD more than keeps up, the question is how long will do it for? Difficult to quantify because it depends on type of usage.

Incidentally the three times I have connected the RavPower today in USB-PD mode, it has not needed reversing once.

 

[objektør]

I understand your decision! The USB-C (PD) technology is very immature and as you say, I expect in a few months there will other products, or none if it turns out USB-PD is not really suitable for batteries. There has to be a reason why there have only been two USB-PD batteries on the market, and one has been withdrawn.

Out of interest I am currently using my MacBook in the top up mode your were considering. As you said USB-A charging barely keeps up with the normal usage, although it does slowly charge the MacBook while in use. USB-PD more than keeps up, the question is how long will do it for? Difficult to quantify because it depends on type of usage.

Incidentally the three times I have connected the RavPower today in USB-PD mode, it has not needed reversing once.

And there is this one:

https://www.amazon.de/dp/B01CBKG0FU

The US and UK Amazon only sell the Poweroak K2 (50.000mAh) but that one doesn't charge the rMB.
Anyhow I think it is too expensive for what it does compared to the Rav which is half the price.

My idea was to use the Rav during the day (3-5 hours) to keep the rMB topped up. In the evening I would turn on the inverter and use the rMB on the inverter/mains while the Rav is getting charged for the next day.
In this way I hope to save what is left of my rMB battery for traveling and/or emergencies (together with the Rav)

 

[Mike Boreham]

My idea was to use the Rav during the day (3-5 hours) to keep the rMB topped up. In the evening I would turn on the inverter and use the rMB on the inverter/mains while the Rav is getting charged for the next day.
In this way I hope to save what is left of my rMB battery for traveling and/or emergencies (together with the Rav)

If your goal is 3-5 hours I think the RavPower would do it easily. I have been using my MacBook with the RavPower connected USB-PD for three hours continuously, but not heavily (but has included updating some VMs in Parallels), and the MacBook is at 100% and the RavPower still has three (out of four) lights on.

 

[objektør]

If your goal is 3-5 hours I think the RavPower would do it easily. I have been using my MacBook with the RavPower connected USB-PD for three hours continuously, but not heavily (but has included updating some VMs in Parallels), and the MacBook is at 100% and the RavPower still has three (out of four) lights on.

Thank you! That is exactly what I wanted to know. Of what you say I would even get 5-8 hours out of the RavPower to keep my rMB topped up (I'm no heavy user) and that fits my needs perfectly.
I still might get me one when in the EU next month. The price (60€) is not too bad compared to the Rav with AC outlet (160€) or a new rMB battery (250€). Worth a try at least.

 

[Mike Boreham]

I realise I have been making a rather naive mistake in presenting and discussing my test results so far. My results make more sense to me now.

Because every battery of this type I have ever used before has been a 5V device I have been treating mAh numbers as a measure of battery capacity, which is what the manufacturers do e.g. "26800 mAh" "20100 mAh". However these only express the current and time it can supply at 5V.

Current x time (mAh) is not battery capacity. Battery capacity is correctly expressed as watt-hour, or current x voltage x time.

This explains why my Satechi USB power meter records the following to fully charge a flat RavPower:-

20,461 mAh at 5V equals 102 Wh (this is a correction to initial post, used wrong # from table)
6,700 mAh at 15V (Apple charger) equals 100 Wh
4,950 mAh at 20V (RavPower charger) equals 99 Wh

It also makes sense of the regular USB-A charging compared to the USB-PD:

10-100% used 10130mAh at 5V equals 51 Wh,
plus 10-61% used 5097mAh at 5V equals 25 Wh.
Total delivered by one full RavPower by USB-A equals 76 Wh

0-100% used 4390 mAh at 15V equals 66 Wh with a bit left over, so similar to USB-A result.

The MacBook battery is 39.7 Watt-hour (e.g.here) compared with 99.16 Watt-hour for the RavPower. With a typical 60% transfer efficiency that means the usable capacity of the RavPower is about 60 watt-hour, 1.5x the MacBook's watt-hour. This is close to the 1.3x you found on the website, and closer to my experience, and about the same as I found with regular USB-A (5V) charging.

I am not sure what voltage the Coconut values are, e.g. the nominal capacity is expressed as 5550 mAh. Comparing this with the 4390 mAh at 15V which it took to charge my 90% health MacBook, the Coconut figures seem consistent with the USB-PD 15V numbers.

I understand why mAh is widely used to express battery capacity, and the manufacturers do it to be able to quote nice big numbers, but it is misleading when different voltages are involved.

Apologies if you were ahead of me in this mAh vs Wh at different voltages issue! Allowing for a bit of experimental error and variability my results all make more sense to me when expressed in terms of Watt-hours.

BTW:-
-The RavPower charged from flat to full in exactly 4 hours using the Apple charger (15V).
-Using the RavPower in USB-PD top up mode yesterday it lasted about 5h45m before being flat. At the end the MacBook was still at 100%. The MacBook had been on continuously (no machine or screen sleep) in that period and in use for most of it including some Photos and Lightroom and Parallels VM work.
- Three more connections of the RavPower without need to reverse the current.

I have edited the above quite a bit since original post.

 

[Mike Boreham]

For anyone confused by my rather rambling and heavily edited last post, my executive summary about the RavPower that it has a usable capacity in the range 65-75 watt-hour, so is capable of charging the 40 watt-hour MacBook about 1.5 times, whether by USB-A (5V) or USB-PD (15V). The numbers don't quite fit but this is not an exact science.

When I bought the RavPower I was thinking 26,800 mAh sounded a lot compared to the 5,550 mAh that Coconut shows as the MacBook design capacity, so in theory nearly five times. (I didn't really think that, but that is the superficial interpretation of the numbers).

Transfer efficiency and the difference between milliamp-hour values at 5V and 15V mean the reality is very different. Now I understand exactly what it is and can do, I am quite happy with it.

The other lesson I have learned is that USB-PD mode is not available when the battery is partially charged. If you connect it by UDB-PD it will go through to full discharge all at USB-PD, but of you disconnect it and reconnect it it will be likely to reverse. So to make use of a partially charged battery it needs to be connected by USB-A. I am not sure where the threshold is. Moral is to have both types of cable.

 

[objektør]

The MacBook battery is 39.7 Watt-hour (e.g.here) compared with 99.16 Watt-hour for the RavPower. With a typical 60% transfer efficiency that means the usable capacity of the RavPower is about 60 watt-hour, 1.5x the MacBook's watt-hour. This is close to the 1.3x you found on the website, and closer to my experience, and about the same as I found with regular USB-A (5V) charging.

BTW:-
-The RavPower charged from flat to full in exactly 4 hours using the Apple charger (15V).
-Using the RavPower in USB-PD top up mode yesterday it lasted about 5h45m before being flat. At the end the MacBook was still at 100%. The MacBook had been on continuously (no machine or screen sleep) in that period and in use for most of it including some Photos and Lightroom and Parallels VM work.
- Three more connections of the RavPower without need to reverse the current.
- I am going to repeat the 15200 mAh at 5V test above as 76Wh looks a bit low compared to the other two. They were the first measurements I made and I am wondering if the cycling has brought the capacity up a bit.

I have edited the above quite a bit since original post.

Thanks again. It is really good to get some figures from real life testing.
I didn't expect a 26.800mAh battery bank to charge my rMB 5 times but hoped for 3. My Anker E5 (15.000mAh) didn't manage to fully charge my rMB so I was prepared in a way but it is still disappointing. All your measuring shows that 1,5 times is more realistic. So now I know what I will get if I buy one.

Only 4 hours to fully charge the Rav is very good though.
And to keep my rMB topped up for almost 6 hours isn't too bad either. It fits my needs.
At what brightness did you keep it topped up? I'm at 50% brightness (or less) most of the time. Screen brightness is what influences my battery life most in my daily usage (reading PDF, writing Pages, iBooks, browsing, Keynote. No YouTube or movies).

 

[Mike Boreham]

At what brightness did you keep it topped up? I'm at 50% brightness (or less) most of the time. Screen brightness is what influences my battery life most in my daily usage (reading PDF, writing Pages, iBooks, browsing, Keynote. No YouTube or movies).

My brightness is at max.

 

[objektør]

My brightness is at max.

That's very good news. For me.
It means that the RavPower will easily keep my rMB topped up for 6-8 hours. Maybe even more if I get 1,5 times my rMB battery out of it.
That makes it a no brainer for me and well worth the investment.

 

[Mike Boreham]

One more data point before I stop testing the thing and just use it!

The RavPower charged the MacBook from 10-100% and then 2-89% from a singe charge, all in USB-PD mode.

The total delivered was 5066 mAh at 15.4V equals 78 watt-hour.

After the first charge period the RavPower had two lights showing. On reconnection for the second charge the flow needed reversing but did so readily with the button push.

The difference from the previous USB-PD test was that for these two charge periods the mac was shut down, so not using any power. Not such a realistic case as recharging while being used, but a better measure of the battery capability to compare with spec.

This result fits well with the earlier USB-A testing (15227 mAh at 5V equals 76 watt-hour) and the spec capacity of 99 watt-hour, showing a transfer efficiency of about 77%.

After setbacks and misunderstanding I now regard the RavPower as a solid product. The USB-PD feature means it has fast charging and recharging, and is able to supply same power to MacBook as wall charger.

 

[objektør]

One more data point before I stop testing the thing and just use it!

The RavPower charged the MacBook from 10-100% and then 2-89% from a singe charge, all in USB-PD mode.

The total delivered was 5066 mAh at 15.4V equals 78 watt-hour.

After the first charge period the RavPower had two lights showing. On reconnection for the second charge the flow needed reversing but did so readily with the button push.

The difference from the previous USB-PD test was that for these two charge periods the mac was shut down, so not using any power. Not such a realistic case as recharging while being used, but a better measure of the battery capability to compare with spec.

This result fits well with the earlier USB-A testing (15227 mAh at 5V equals 76 watt-hour) and the spec capacity of 99 watt-hour, showing a transfer efficiency of about 77%.

After setbacks and misunderstanding I now regard the RavPower as a solid product. The USB-PD feature means it has fast charging and recharging, and is able to supply same power to MacBook as wall charger.

Use and enjoy it!
I'm pretty sure (after all your testing) that it will do what I need: keeping my rMB topped up for at least 6 hours ( with my normal usage probably 10 hours).
Fast recharging is a great plus as well. And the price is good for what it does.

 

[Mike Boreham]

The other lesson I have learned is that USB-PD mode is not available when the battery is partially charged. If you connect it by UDB-PD it will go through to full discharge all at USB-PD, but of you disconnect it and reconnect it it will be likely to reverse. So to make use of a partially charged battery it needs to be connected by USB-A. I am not sure where the threshold is. Moral is to have both types of cable.

I reported this to RavPower Support, and they have sent me a replacement, which does not have this characteristic. The current flow does not reverse, even when the RavPower is connected in quite a low state of charge. They do not require the old one back so now I have two!

Interestingly the revised(?) replacement is supplied without the much criticised USB-C charger but with a USB-C to USB-C cable.

 

[objektør]

I reported this to RavPower Support, and they have sent me a replacement, which does not have this characteristic. The current flow does not reverse, even when the RavPower is connected in quite a low state of charge. They do not require the old one back so now I have two!

Interestingly the revised(?) replacement is supplied without the much criticised USB-C charger but with a USB-C to USB-C cable.

Thanks for the update.
I got mine 6 weeks ago together with an Aukey car charger 12V with PD. Both worked fine straight out of the box.
No problems with reverse current flow on either of them.
Used the RavPower to start with, while traveling. Just used it, did not notice any of the 'problems' you had.
At home I've been using the Aukey straight from the solar panel battery. Very pleased with that one.
Will be using the RavPower later on after the summer when the solarpanel stops charging (because of situated north from the arctic circle)

 

[Mike Boreham]

BTW...Anker seem to have reintroduced their 26800 PD battery. They had one advertised quite widely last year, but it was unavailable everywhere. I asked Anker and they said it had been withdrawn. Now it, or a new version of it is available again:

https://www.anker.com/products/B1375111