GP Smart 2 PowerBank 1 Hour Fast Charger GPPB14

[Mr Happy]

I just spotted this in Boots at £19.99 and couldn't resist a new toy :devil:

Here are its features:

It charges AA's at 2000 mA (NiHM) or 1000 mA (NiCd), AAA at 1000 mA (NiMH) or 400 mA (NiCd). It has four independent charging channels and each channel has individual -dV, temperature sensing and timer charge controls. There are individual LED indicators for each channel and it seems like each channel can start and stop independently of the others.

(Note: It has since been found that the charger has a 90 minute timer cut-off, so it will not fully charge an NiMH cell of capacity higher than ~1500 mAh when set to the 'soft' NiCd setting. To fully charge NiMH cells you have to use the higher charge rate with the switch in the NiMH position.)

A worldwide external power adapter is included in the package and it has a 12 V input so can be used with a car adapter (not included).

It seems like it might be the ideal everyday use compact charger that I have not managed to find yet. Further reports will follow after I have tested it a bit.

I'm posting this because I have not seen any reviews of this charger so far, and so it might be of interest especially to UK residents.

 

[ELDRAW]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

thanks i might pick one of those up for £20. Is it the same as this one: http://www.flashaholics.co.uk/batteries/gp-u-smart.html

 

[mfm]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

Almost like the NC-MQH02 but less suitable for eneloops (trickle charges), probably lower quality and a higher price?

The one linked by ELDRAW is some old 30 min charger with outdated technology: "Charge NiMH batteries by switching to "NiMH", or "NiCd" for charging NiCd batteries"

 

[Mr Happy]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

thanks i might pick one of those up for £20. Is it the same as this one: http://www.flashaholics.co.uk/batteries/gp-u-smart.html

No, it is this charger:

http://www.gppowerbank.co.uk/product_info.php?cPath=21_24&products_id=46

The Boots version comes with 2200 mAh batteries, but since they seemed to be completely empty out of the package you probably wouldn't buy this charger for the included cells.

 

[Mr Happy]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

Almost like the NC-MQH02 but less suitable for eneloops (trickle charges), probably lower quality and a higher price?

The one linked by ELDRAW is some old 30 min charger with outdated technology: "Charge NiMH batteries by switching to "NiMH", or "NiCd" for charging NiCd batteries"

That's not outdated technology, that's good technology. This one has a switch too. On the NiMH setting it charges at 2000 mA, on the NiCd setting it charges at 1000 mA. That's what I'm calling the "fast" and "soft" settings.

It is potentially ideal for eneloops with those charging rates.

I'm charging the included batteries right now to see how warm they get.

 

[Niconical]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

I have some experience with GP chargers. They have a few in different shapes and forms that have what we would consider the" required features", 4 channels, good termination, and a 0.5C to 1C charge rate. For the price they seem good.

As for their batteries, the GP Recyko are very good, near eneloop.
On the other hand all their other (non LSD) batteries are no more than package fillers, IMO.

 

[Egsise]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

As for their batteries, the GP Recyko are very good, near eneloop.

WHOA!
Check out the freezer test and say that again...

As for the charger, any information about the trickle charge, mA's?

 

[Mr Happy]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

Well I charged the included batteries on the soft (NiCd) setting and they terminated at the expected time without apparently getting too warm (I wasn't there at the point of termination but they were only gently warm a few minutes earlier). That's a good sign.

The charger itself feels very solid and well made. It did not itself get warm during the charging, which is an expected benefit of an external power adapter. Also the charger has a neatly designed ventilation grille.

As for the trickle charge, this is 80 mA (AA)/40 mA (AAA) on the NiMH setting, 40/20 mA on the NiCd setting.

I am beginning to be optimistic about this charger being a good one.

 

[SilverFox]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

Hello Mr Happy,

Interesting...

I just picked up the PowerBank Smart charger. It looks like the same charger, however it charges at 1600 mA for NiMh and 800 for NiCd. The tricke charge rate is the same as your charger.

I tried charging some Eneloop cells on the NiCd setting and it did not fully charge them. It looks like the safety timer shuts things off at about 2.5 hours.

It does a good job on the NiMh setting, but the cells do warm up at the end of the charge. I haven't checked the cell temperature yet, but they are about as hot as I would care to hold in my hand without discomfort.

On this charger you flip down the + contacts to change the spacing to charge AAA cells. AAA cells seem to charge OK too. The charge rate for NiMh AAA cells is 800 mA and 400 mA for NiCd AAA cells.

I am going to half discharge some Eneloop cells and then charge them using the NiCd setting to see how much they heat up.

Overall, I think it is a decent charger. I am not sure which is better, charging at 1600 mA or charging at 2000 mA.

Tom

 

[Mr Happy]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

Interesting...

I just picked up the PowerBank Smart charger. It looks like the same charger, however it charges at 1600 mA for NiMh and 800 for NiCd. The tricke charge rate is the same as your charger.

I tried charging some Eneloop cells on the NiCd setting and it did not fully charge them. It looks like the safety timer shuts things off at about 2.5 hours.

It does a good job on the NiMh setting, but the cells do warm up at the end of the charge. I haven't checked the cell temperature yet, but they are about as hot as I would care to hold in my hand without discomfort.

I also noticed what might have been an early termination, but as the batteries were brand new and had arrived discharged I did not want to read too much into a single result.

Also, it might have been the temperature sensor which stopped them, possibly? My charger has very functional looking temperature sensors in each cell bay, and the manual has this to say: "If charging is done at temperatures above 30°C, the LED indicators may go on and off several times until the batteries achieve a full charge condition." This implies the charger has a high temperature override that will temporarily interrupt charging if the batteries get too hot.

The instructions also say, "It is normal for the batteries to become hot during charging and they will gradually cool down to room temperature after fully charged."

On this charger you flip down the + contacts to change the spacing to charge AAA cells. AAA cells seem to charge OK too. The charge rate for NiMh AAA cells is 800 mA and 400 mA for NiCd AAA cells.

Yes, mine is the same. This leads to a slight drawback that you can't charge a mix of AA and AAA cells at the same time. I don't feel that is too serious though.

I am going to half discharge some Eneloop cells and then charge them using the NiCd setting to see how much they heat up.

Overall, I think it is a decent charger. I am not sure which is better, charging at 1600 mA or charging at 2000 mA.

I will be very interested to learn your further test results. I don't have my C9000 with me right now so I am limited in what tests I can do until I get back home.

 

[SilverFox]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

Hello Mr Happy,

On the Smart charger (yours is the Smart 2), the NiCd charge terminates at 90 minutes. I thought it ran longer, but finally got around to watching it closely.

With half discharged Eneloop cells, the charger seems to fully charge them on the NiCd setting, but it comes a little short of a full charge if the cells are completely discharged.

Tom

 

[Mr Happy]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

I found a specification sheet that says the Smart 2 charger also has a safety timer at 1h 25m, and I have confirmed that by testing. It's a pity that you can't charge a full capacity NiMH cell at the slower rate.

The same specification sheet said that the high temperature limit is set at 55°C ± 5°C.

I have not tried the fast NiMH charge rate yet.

 

[Lynx_Arc]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

sounds a lot like my rayovac 1 hour charger to me

 

[Mr Happy]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

It does a good job on the NiMh setting, but the cells do warm up at the end of the charge. I haven't checked the cell temperature yet, but they are about as hot as I would care to hold in my hand without discomfort.

Yes, having charged the included cells on the NiMH setting this is my experience too. The batteries get toasty hot at the end of charge, and the charger itself gets a bit warm underneath.

I suspect this is the inevitable consequence of charging NiMH cells at the 1C rate right up to the -dV point. To do better than that I think a charger would need to intelligently reduce the charging rate as the cells neared a full charge.

So far then, I think this charger is not quite as wonderful as I thought it might be at the top of the thread, but it is still a decent charger to consider for someone who wants a basic fast charger that has good specifications.

The 90 minute safety timer is a pity for using the gentler NiCd setting on NiMH cells, but on the other hand it should prevent meltdown events if there should ever be a missed termination.

 

[mfm]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

I suspect this is the inevitable consequence of charging NiMH cells at the 1C rate right up to the -dV point. To do better than that I think a charger would need to intelligently reduce the charging rate as the cells neared a full charge.

It would be good if you could try with eneloops and give exact readings using an IR thermometer before making any broad statements about 1C and NiMH cells in general...

 

[Mr Happy]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

I suspect...

It would be good if you could try with eneloops and give exact readings using an IR thermometer before making any broad statements about 1C and NiMH cells in general...

I tried charging some Eneloop cells ... It does a good job on the NiMh setting, but the cells do warm up at the end of the charge. I haven't checked the cell temperature yet, but they are about as hot as I would care to hold in my hand without discomfort.

I do suspect I am not wrong, but when I have an opportunity to charge some eneloops and measure the temperature with an IR thermometer I will be happy to oblige. Right now I find Tom's description of how hot the eneloops got was about as perfect a description as I could imagine of how hot the GP cells got. Even eneloops have to obey the laws of physics.

 

[SilverFox]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

Hello Mr Happy,

The hot toasty cells that I mentioned were the GP 2100 cells that came with the charger. Initially they had around 1.1 volts, but they are coming in at about 1600 mAh. These cells get hot during the end of the charge.

I have now casually checked the heat while going through a few charge cycles with some Eneloop cells, and they warm up, but not nearly as much as the GP cells did. This is also the case with some 2600 mAh cells that I tried.

It is looking like a charge + 2 hours trickle charge gets the Eneloop cells very near fully charged.

Tom

 

[Mr Happy]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

The hot toasty cells that I mentioned were the GP 2100 cells that came with the charger. Initially they had around 1.1 volts, but they are coming in at about 1600 mAh. These cells get hot during the end of the charge.

I have now casually checked the heat while going through a few charge cycles with some Eneloop cells, and they warm up, but not nearly as much as the GP cells did. This is also the case with some 2600 mAh cells that I tried.

It is looking like a charge + 2 hours trickle charge gets the Eneloop cells very near fully charged.

Ah, if the eneloops don't get so hot that seems like less cause for alarm then.

The GP cells that came with mine are marked 2200 mAh and have a Boots brand wrapper on them, but I didn't have a voltmeter to measure what they were out of the package. I think they were somewhat empty as they wouldn't operate my LED flashlight at all.

 

[Mr Happy]

Re: GP Smart 2 PowerBank 1 Hour Fast Charger

I have now charged some Eneloops in this charger, starting from a fully discharged state. The results were somewhat consistent in two separate tests. Charging took almost exactly one hour, and the peak cell temperature measured by an infrared thermometer was 56°C in slot 2. Slots 1 & 3 were similar, while slot 4 was only 45°C. I would describe the hottest cell temperature as 'very warm, nearly uncomfortable to hold'.

The difference in temperatures was the same even when I swapped the cells around in a different test. This seems to indicate that the charger contributes some of its own heat to the cells and shows how important it is to keep electronics away from the charging bays when designing fast chargers.

When the Eneloops were removed and allowed to cool without any further trickle charge, they recorded about 1850 mAh when subsequently discharged on the C9000. This indicates that the Smart 2 charger is achieving a reasonably complete charge in the claimed 1 hour charging period.

I still have a favorable impression of this charger.

 

[espresso]

Hello,

I found this topic very informative. I'd also like to share my experience with Smart 2 charger.
There isn't a great choice of smart chargers in my country so when I ran into this one it seemed like a good thing to buy.
It cost around 31€ which is significantly higher price than you paid. Smart 2 is indeed well built. Here are some pictures that I've taken
http://www.flickr.com/photos/53862392@N07/sets/72157625030908740/show/with/5023389412/

Mr Happy mentioned that his batteries get very hot at the end of the charge. In my case too. First I tried charging the supplied 2500 mAh batteries. After that I tried Eneloops. In both cases the batteries get so hot that you can't even hold them in your hand for too long. And of course, the battery that is furthest to the right doesn't get as hot as the rest.
The heat from the charger definitely has an impact on the batteries.

I'll use a PC fan to get rid of the excess heat or simply charge the batteries in a cold room (during winter).

Is there a charger with temperature compesation? It should reduce the current as the battery heats up. That would be the ultimate charge for me.

@Mr Happy
Where did you read this:

I found a specification sheet that says the Smart 2 charger also has a safety timer at 1h 25m
...
The same specification sheet said that the high temperature limit is set at 55°C ± 5°C.

And finally, how does this charger serve you, do you still use it?