Looking for a USB powered NiMH charger and ran across the above little item on Amazon. Any one know anything about it? Claims to be a USB powered NiMH charger for up to four AAA or AA batteries which can also act as a power bank for charging phones etc using either charged NiMH or disposable Alkaline batteries. Seems like a pretty versatile little device if the claims are true. Reasonably priced too. Love to see someone test it as a search of the site indicates it has not been posted about before, at least under the PortaPow name.
Why not ask them for a review sample and do that first review? You sound as skilled as almost anyone here, and would probably do a great review. I don't think I can take on another review unless I just plug in some batteries and a USB Charger Doctor and put a time lapse camera on it, and basically just post a copy of the time lapse video.
NiMH requires higher current charging (above 0.5C if I remember correctly, that equates to above 1A for most new AA batteries) to be able to detect charge finish by voltage drop. I don’t think USB can provide high enough currents to properly detect charge termination.
I suspect that is dependent on the charger and how sensitive the sensing is set. The factory inexpensive eneloop charger included with some retail Eneloop battery packs is a relatively low current charger but seems to terminate based on charge level rather than time. The same for the Nitecore/Sysmax intellicharger I4 which handles NiMH and Lithium Ion batteries and the LaCrosse Technology BC-700 and BC-1000 NiMH chargers which offer selectable charging current choices.
I often read that you need high enough currents that will cause temperature rise and voltage drop otherwise you don’t detect the voltage drop at all. I’ll test it one of these days.
After reading the number of Amazon reviews reporting DOA or very early life failures I looked around some more and found a new Maha charger that I have ordered.
Looks like it includes USB battery charging capability based on the “Key Features” list and Maha has a good reputation for quality chargers as I recall. I did not find any USA sources for this model yet and the older Sanyo two AA or AAA NiMH USB charger now has one Amazon listing and is over $200. A discontinued item and the new Maha seems to be about the only hopefully decent alternative. Per reviews all the alternatives seem to be junk. The Maha looks to be pretty versatile based on the key features list but we shall see.
@Rich, You sure that ebay charger is MAHA branded? It looks like some korean company that throws out other names to generate interest. Either way, could be an interesting product. Main design oversight I see is the lack of a standard USB plug like a micro or mini to power the charger so you don’t have to pack lame cables around.
HB; Checked and you are right it looks like. I remember when I was in the Navy during the Vietnam era Taiwan was notorious for ignoring international copyrights and apparently they still are. In the late 1960’s you could get a pirated copy of the Encyclopedia Britannica for about 10% of the USA price I was told by fellow sailors who had visited there. I personally HATE to buy fakes or name ripoff items but in this case they are offering an item which is not offered by others at all, IF it is decent quality. It could be OK or a total ripoff.
I would prefer the Sanyo but it is discontinued and the price for those still available has gone through the roof. Everything else even semi comparable seems to be a POS in comparison except POSSIBLY the “Maha”.