Not all battery chargers are made equal

[davetherayon]

This is about a couple of battery chargers I bought; not ecig ones as it happens, but blimey if this is the standard manufacturers adhere to, what chance does Joseph (and Jane) Public stand?

Background - I bought a cordless mouse for my PC, and decided to get some rechargeable AAAs and a charger for it. Did a bit of websearch and found two... both are wall warts (plug into the mains socket).

1. The Good

A charger that glows red on charge, green on full charge, and cuts itself out on full charge. Cost : £10.28. Maker : Duracell.

2. The Ugly, and Bad

A charger that glows on charge. Quote "The two LEDs are not switched off when the batteries are fully charged". Your 'protection' is a list of recommended charging times in the pamphlet. Cost : £ 7.99. Seller : Maplin. In their Q&A they state "the lights only indicate charging and there is no cut off."

Nobody buy the latter (I bought both; the latter first, then the former after realising how dire the Maplin offering is).

Re vaping, hope to hell this "shit will do" manufacturing/selling strategy isn't prevalent. I've been using an Xtar WP2 for a couple of years and, crossed fingers, it's been fine to date. Anyone with more knowledge (VapingBad ?) your experience is welcome.

[VapingBad]

It is not dangerous (for a few hours anyway) continuing to charge NiCad & NiMh batteries after they are fully charged, most of the early NiCad chargers just trickle charge once full and for a while that a good thing. IIWY would look for a delta V one (delta as in calculus and V as in volts), 7dayshop do some OK ones for very little, I have a Voltcraft that does discharge/recharge & conditioning, but use a lot on NiMh batts for camping.

For Li batteries this is one of the worst things you can do: leaving them on a charger that doesn't completely stop charging them once full.

[osdset]

Most of the stuff Maplin sells is dire, overpriced and dire.

[davetherayon]

Question arising from that (thanks for the quick reply VapingBad btw). I don't have any Li-Ion devices, 18490/18500/18650 in all my mods. However if you do have a flatpack that uses Li-Ions are there issues potentially charging them from usb? The itaste I used to have was usb charged. Long gone now, but there will be plenty out there.

[thatguy]

The worst NiCad/NiMH I've come across are from a reasonably well respected high street name...uniross. Both chargers I've had from them claimed to apply a trickle charge once fuly charged, but they both left cells at over 60 degrees C (62 degrees and 66 degrees) once left on trickle charge for 90 mins. Not only is this potentially dangerous for the average punter who will charge batteries overnight or whilst at work, it has a negative impact on the lifespan of secondary cells. Even worse was the fact that they had no indicator of charge state, just a power LED for each of the 4 bays.

Perhaps we should be looking at creating a list of good charger models as well as cells for vaping. The nitecore I/D 2/4 range are great investments as they not only charge lithium cells but also NiCad and NiMH cells. They may be slower than some other chargers due to smaller charge currents but they are far more versatile, they are safe (as long as they are not fakes) and the slower charge will prevent unneccecery degredation of cells.

[VapingBad]

May 30, 2015 0:30:50 GMT davetherayon said:

Question arising from that (thanks for the quick reply VapingBad btw). I don't have any Li-Ion devices, 18490/18500/18650 in all my mods. However if you do have a flatpack that uses Li-Ions are there issues potentially charging them from usb? The itaste I used to have was usb charged. Long gone now, but there will be plenty out there.

There shouldn't be if everything is of OK or above quality, as chargers should always regulate how much current the take, but keeping the supply near the max current the device wants gives you a extra level of safety.  The only thing that can be a problem is if you mains earth is dirty (the odd spike) it may get through to the negative of a PC USB, again modern kit should be OK, but this is why you some times see instructions saying not to charge from a computer.

There is more in the battery guide in my footer in the USB charged devices section.

[VapingBad]

from Battey Uni

NiMH dislike overcharge and the trickle charge is set to around 0.05C. In comparison, NiCd is better able to absorbed overcharge and can take 0.1C. Differences in trickle charge and the need for a more sensitive full-charge detection render the original NiCd charger unsuitable for NiMH batteries. A NiMH in a NiCd charger would overheat, but a NiCd in a NiMH charger functions well. The lower trickle charge for NiMH is sufficient for NiCd.

So older chargers for NiCad tend to trickle charge, but it need tighter control for NiMh at a lower current, but they both can trickle charge.

Simple Guidelines on Charging Nickel-based Batteries

Below 70 percent, the charge efficiency of nickel-based batteries is close to 100 percent. The pack remains cool but it begins to warm up towards full-charge.

Nickel-based batteries must cool down on trickle charge when ready, especially NiMH.

Consumer chargers do not always terminate the charge correctly. Remove the batteries when warm to the touch. Discontinue using a charger that “cooks” the batteries.

Charge at room temperature. Do not charge when hot or at freezing temperatures. (See BU-410: Charging at High and Low Temperatures)

Nickel-based batteries are best fast charged; a lingering slow charge causes memory.

NiMH chargers can charge NiCd, but not the other way. NiCd chargers overcharge NiMH.

Do not leave a nickel-based battery in the charger for more than a few days. If possible, remove the packs and apply a brief charge before use.

Nickel- and lithium-based batteries require different charge algorithms. Unless provisions are made, these two chemistries cannot share the same charger.

[Deleted]

May 30, 2015 0:28:59 GMT osdset said:

Most of the stuff Maplin sells is dire, overpriced and dire.

I have never shopped there since , and never will in future solely down to two visits I made , each time the cashier held the £20 note up to the light in front of the folk standing in the que, making you feel like some big time fraudster!

I said to him can you not do that by some other means, I have no problem with retailers checking for forged notes etc, just the manner in which this store chain seems to think is acceptable! I wrote to head office about it, and they said basically tough!

1 lost customer here then!