NiMH charger

[duncan webster 1Participant @duncanwebster1]

I'm building a portable electronics thing which will run on a PP3 battery, so I'm looking at getting a rechargeable battery and a charger. Anyone got experience of this thing (Ebay's best)?

**LINK**

I don't need fast charge, but it will be left on charge for a long time, so I don't want to cook the battery

[duncan webster 1Participant @duncanwebster1]

[SteviegtrParticipant @steviegtr]

Not sure about that charger. It gives charge times but no mention of auto cut off when charged. You could always plug it into a timer of sorts.

Steve.

[Martin KyteParticipant @martinkyte99762]

Hi Duncan

Here is the manual.

**LINK**

It's not a very clever charger and states you should time your charge cycles.

If you are going to use NiMH you may be better off with a fully automated charger. The terminal voltage on NiMH cells rises to a peak and then drops off when charging from a constant current source which intelligent chargers use to detect full charge and automatic switch off. You may however be happy with trickle charging or as been already suggested get a timer too, but I would generally choose the battery first and then select the charger from the battery spec.

regards Martin

[not done it yetParticipant @notdoneityet]

Hi Duncan,

Dunno what you are making, but these days I would likely go for 10-10.5V or 7V (or so) power supply. Two or three LiPO4 cells in series. Capacity is far in excess of the ubiquitous PP3. Charging for these is better done as single cells.

If size is important, along with voltage, fair do’s, but I would use a smaller size of Lipo cell, not the 18650. Neither Lipo or NiMH will stand being completely discharged, btw.

If that were a goer, I would recommend a nitecore charger (they don’t seem to offer a PP3 option) – mine has been reliable and is supposed to be ‘intelligent’. More money but 18650s are so common these days that it seemed the way to go for me.

I have one or two old multi-chargers for NiMH and Nicads which will also charge PP3, but they rarely get used as the charge content of a PP3 is so small. I would not leave a PP3 on charge permanently. I ruined one, a long time ago – too much current for too long.🙂

An alternative to extended charging might be regular top-ups via a timer. More expense again and on-going leccy usage (not much on the electronic timers)

[Derek GreenhalghParticipant @derekgreenhalgh23299]

I don't know if you already know about them but you can now get the 9v PP3 in lithium ion that charge directly by usb, they also have more mah, about 500 as apposed to 200-280 mah of the normal rechargable nicad or nimh. I got one of those multi chargers from lidl to charge mine when not in a hurry. I also use an accucell6 for most of my other charging needs that can charge quicker if needed.

Derek

[Maurice TaylorParticipant @mauricetaylor82093]

Regarding the PP3 charger there are plenty on ebay for not a lot of money from British based sellers,the one you’ve chosen is from China.I would buy from British seller.

[Boiler BriParticipant @boilerbri]

Duncan. Model boats forum/ website has very useful information about electrics and batteries. Dave Milbourn has some excellent advice

It’s under features

Bri

[Ian PParticipant @ianp]

Posted by Derek Greenhalgh on 30/04/2020 20:39:43:

I don't know if you already know about them but you can now get the 9v PP3 in lithium ion that charge directly by usb, they also have more mah, about 500 as apposed to 200-280 mah of the normal rechargable nicad or nimh. I got one of those multi chargers from lidl to charge mine when not in a hurry. I also use an accucell6 for most of my other charging needs that can charge quicker if needed.

Derek

Plus 1 for this method if your electronic device is not somethings that draws big Amps.

I have dismantled a couple of these rechargeable PP3's and installed them inside bits of test gear (a mini LCD oscilloscope and an ESR tester). Both tended to get left switched on after being used so needing a new Alkaline cell nearly every time I wanted to use them. A bit more work to mount internally compared with just putting the battery in the compartment but not having to remove it to get to the micro USB socket is much more practical.

Charging is easy with a mobile phone charger and the PP3's tiny LED let you know when its fully charged.

Ian P

[Nick Clarke 3Participant @nickclarke3]

PP3 batteries have a maximum charging current 70 – 100 mA as against up to 2A for an AA so they are easier to cook than others using a 'universal' charger.

[Neil WyattModerator @neilwyatt]

Posted by duncan webster on 30/04/2020 19:46:09:

I'm building a portable electronics thing which will run on a PP3 battery, so I'm looking at getting a rechargeable battery and a charger. Anyone got experience of this thing (Ebay's best)?

**LINK**

I don't need fast charge, but it will be left on charge for a long time, so I don't want to cook the battery

These days I use an old phone battery together with a boost module and a lipo charger module.

When I bought a little digital scope kit, I 3D printed a holster for it to take the two modules and a switch, and have a flying lead for the scope. Bulkier than a PP3 but give loads of run time and charges off USB.

(I also have lithium PP3s with these circuits built in (and a usb socket in the bottom!) that I use for effect pedals etc. Google 'poover 9v'.

Neil

[Ady1Participant @ady1]

My trusty old Lidl charger finally conked out and I needed one in a hurry so ended up getting the outrageously priced 30 quid fast charger from Duracell

It doesn't do pp3 though, they are getting pretty rare now

Turns out to be the best charger I've ever got, it's really brill, just so simple and fast

[CirclipParticipant @circlip]

From the notes in the advert

"This conveniently sized charger has an Automatic Short Circuit and Reverse Polarity Protection and an overcharge protection which should provide a trouble free performance over a long period of time."

But we know about chineese volts/amps etc.

Regards Ian.

[Martin WParticipant @martinw]

Duncan

A reputable UK company, see here, is offering these at a very similar price plus 4 x AA rechargeable batteries. The main benefit being that should there be any problems then you have a much better chance of sorting things out. I use them fairly frequently for a variety of products ranging from rechargeable batteries and chargers, memory sticks/cards to printer inks.

Martin

[duncan webster 1Participant @duncanwebster1]

Thanks everyone, I've decided on the Poover route, but NiMh as I can't have the wire sticking out the bottom like Neil's link. There isn't room for anything bigger than pp3 or I'd have gone for a stack of AAA

[Author]

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