1. Home
  2. Electronics Design
  3. Good Emergency Phone Charger

Good Emergency Phone Charger

I've been looking for one of these that is worth having. I tried plenty of lithium emergency battery charger packs. Most had appalling efficiency or were badly made or had batteries so bloated from overcharging the product couldn't be re-assembled after a visual inspection. Some had all the faults combined.

I looked at single cell AA - 5 volt chargers and again it was mixed. Some were too long and batteries needed small rare earth magnets to fit (true!), they were very slow at charging (no surprise) but most would actually discharge the phone if left on overnight(!!!) I found one that was OK but it is now out of stock.

So I was building my own for the bug-out-bag, when I found this:

formatting link

It is only micro-usb but if that suits you this thing charges a 1000maH phone cell in about 3.5 hours and is OK if left on overnight $6!

Reply to
David Eather
Loading thread data ...

formatting link

Got any info on the power drain when unplugged? Would make a nice 5V portable power supply if it didn't run the batteries down when not supplying 5V power.

Reply to
mike

formatting link

Slide back off cellphone. Insert spare battery. Slide back onto cellphone. End of story.

Never buy a phone where you can't replace the battery. Never.

What costs money in a phone? Connectors. The manufacturer pockets the savings and probably laughs that the fool that buys the product. The same goes for flash storage. If you can't add more flash, don't buy the phone.

Reply to
miso

David Eather wrote: (...)

formatting link

I am interested to know it's output voltage measurement, David.

Thanks

--Winston

Reply to
Winston

formatting link

on my unit

5mA - 200+ Hrs standby with a pair of alkalines
Reply to
David Eather

formatting link

Good advice for a normal situation. Spare battery $10 and that problem is solved.

Not so good in a disaster situation. 2-3 days without mains power and trying to contact family / friends / people through an overloaded cell phone network - 2 batteries might not be enough. Even with power if you were stuck in an evacuation centre there is no guarantee you can get access to a mains outlet for three or four hours to recharge a battery.

Reply to
David Eather

formatting link

Thanks, That renders it useless as a general purpose 5V power supply. The lithium usb rechargeable gizmo I have still works after a month.

Reply to
mike

(...)

The reason I ask is that I want to know what prevents me from connecting three alkaline cells in series to power a cell phone that normally gets 5 V from it's USB connection. Clearly it is not the full 5 V but I wonder if that matters, considering the lower voltage of the battery in the phone?

--Winston

Reply to
Winston

I don't know. You could use 4 low self-discharge NiMH that will last

6mth+ and be close enough to 5 to count.
Reply to
David Eather

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.