I cannot seem to find a charger+powerbank that would support LiFePo4 chemistries.
What I am looking for, seems to be a unicorn...
If there is a USB function in a charger, it does not support Lifepo4.
If there is a LifePo4 charging support, then it does not have a 2A Usb port.
Is there such a thing?
Charger Opus BT-C100 early version and updated @ lygte-info.dk
Overall don't expect the USB out thing to be very good in chargers, having to deal with the additional resistance of the charging rail when draining power from a cell is certainly a hurdle. Although its somewhat pricey, this device does nice.
thank you @Barkuti.
I found it for 16$
Yes, you are right, it seems like the USB function is far from ‘quality’.
Not too many options, it seems.
I ended up with a number of good quality 26650 LifePo4 cells, but cannot find a portable usb bank+charger that can support them well.
I have a 26650 bank by Tomo, but that one works for 3.7v li-ion cells only.
I think I found an option
Xtar VP2
https://lygte-info.dk/review/Review%20Charger%20Xtar%20VP2%20UK.html
the only thing that’s not clear, is that HJK mentions in his review, that red light flashes when battery is below 3.15V, but LifePo4 batteries will stay below 3.15V for quite a bit of time (as they are lower voltage), will USB output work ok?
That Xtar VP2 looks pretty nice worker. However, the power bank / USB output function is designed to operate with li-ion cells. It is unlikely that it will work right with LiFePO4 cells because of the rail resistance burden. Battery load multiplied by rail and rail contacts resistances causes a voltage drop over the own battery output voltage, and to make things worse the VP2 cuts at 3.0 V (pretty bad). Could work, you can try, but you will need to always keep cell and rail contacts super clean and use healthy cells (I wouldn't count on it).
that’s a bummer!
VP2 has a switch on the back to switch voltage, and I thought if I put it on 3.2, it would tell the usb-function, I have lifepo4 cells.
I don't know if there are any comercially available power bank devices designed to work with LiFePO4 cells, so far I haven't found or seen them.
There are some boost converter boards which could operate with LiFePO4 batteries, but that would be a DIY solution which involves time and effort. It would require some LiFePO4 BMS, boost converter board, box, switch, batteries, etc. Far from what you are looking for, in any case.
you are probably right.
In the mean time, found another charger that charges LifePo4, and has USB out
(but again, may be, as you are saying, the USB will not work with LifePo4)
Liitokala Lii100
https://lygte-info.dk/review/Review%20Charger%20LiitoKala%20Lii-100%20UK.html
I have a Lii100 and a bunch of LiFePo4 18650s. I can try out the USB output with them and get back to you. Just need to find a suitable load.
I am very grateful, thank you in advance treellama.
A Lii-100 cannot deliver 2 A, it's output is 1 A rated and according to HKJ's test delivers up to 1.3 A before its output voltage starts dropping. It also cuts off at or above 3.1 V, so good luck with LiFePO4.
I can confirm, USB power bank is a no-go with LiFePo4 on Lii-100. It lights a USB desk lamp but after a few seconds when the battery voltage is pulled down it shuts off.
If you have a lot of LiFePo4 batteries, my suggestion would be to connect four in series, and use a 12V -> USB car charger.
Got it. Thank you.
My lifepo4 batteries are 26650.
I saw 4s BMSs to build a 12v DIY pack.
But was hoping for something single cell (or 2), portable and pre built, something that can charge the cell, and boost it up to 5V for a USB (at 2A, ideally).
Something like TalentCell 12V LiFePO4
but with replaceable cells (also note that talentcell uses 32700, which are probably even better efficiency wise)
Looks like 26650 and 32700 lifepo4 are for DIYers.