Best 'slow' charger

Best \'slow\' charger

Has anyone used this charger or have an opinion on it? Slow Charger I'm looking for a charger for 1800mah NiMh AA that I can slow charge and leave in the charger until used. I have several sets so I don't care if it takes days to charge. I also want to be able to charge each cell individually, which it says it does. Even though it says it will, I'm worried that it will never really fully charge these batteries.

Re: Best \'slow\' charger

Well...

Why don't you think it will funny charge the cell? Fast charging is actually better for NiMh cells...you can pack more power into them, but slow charging is fine as well and much cheaper except for something like that which will do 100 batteries at once I suppose.

If you need to charge like 10 batteries at once that might be a good charger, but if you're only doing 3 or 4 batts at a time fast chargers switch into trickle charge--you can leave that batts in as long as you want.

Re: Best \'slow\' charger

I extrapolate what I think I know about nimh batteries from what I know I know about my lead-acids..and one thing I know about the lead-acids is that it takes much longer to put in that last 10%-15% of capacity than the previous 85-90%%..2 or 3 times longer in fact..so it would be interesting to keep notes with that charger and see if the voltage can be raised to equal nimhs from a faster charger (don't forget to let them rest a while before measuring them) -- it may take longer than 18 hours, maybe a couple, three days, but the slower-charged batteries may eventually get up to the voltage of the faster-charged batteries...the text of that charger seems to imply it switches to a slower charge once the batteries are full, though... " After the batteries are fully charged this charger maintains the charge with a slow trickle charge..."

Re: Best \'slow\' charger

I would use some caution in buying this slow charger and I would see if they have a money back policy. As I understand and with experience, NiMH cells are fully charged when a rather high amount of current is applied. I think the ideal charge rate is about 0.5 Amps and a 1,600 mA cells will require about 3 hours to charge at this fast rate. The Quest Q2 falls into this range. Faster chargers like the Rayovac PS4 charges at around 1.5 Amps and will require about 1 hour. This is about the fastest you can charge, and there are discussions that this may be too fast. Nothing has been proven in regards to this concern. I have both chargers and cells are working fine and they have given new life to old NiCad cells which were not doing well in slow chargers...

Let me know if you do get a chance to use this charger. I'm curious to know how good it works as I don't mind being proven wrong. It could fill a niche for my needs. Although, I'm still not sold if it would fully charge the cells...

Re: Best \'slow\' charger

I leave my cells in the C204F al the time. It fast charges them, then goes in to "trickle" charge mode.

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<font size="2" face="Verdana, Arial">I have 2 of the Maha Powerex CR3 chargers I bought from Thomas Distributing. The website says that you can leave them in the charger and 'trickle' charge until needed, but the directions that came with them caution you not to leave them in for an extended time, whatever that is. Also, neither it nor the C204F will charge each cell independently, only in pairs. I use many cells in odd numbers. (FRS radio uses 3)

Re: Best \'slow\' charger

Originally posted by Ted the Led:
it takes much longer to put in that last 10%-15% of capacity than the previous 85-90%%..2 or 3 times longer in fact..

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<font size="2" face="Verdana, Arial">Though I know next to nothing about NiMH's, I can confidently back you up on what you say of lead/acid. My car's pack will charge to 80% in about an hour. That last 20% can take four hours. This is why one of the most common questions (how long does it take to charge) is so hard to answer. For most trips, an 80% charge will do you, but other times you need the pack packed.

OK, I *tried* to stay on topic....

Re: Best \'slow\' charger

Yep, you are all correct on this! The final top off of the cell (about 10%), takes as long or even longer to charge than the previous 90%. I think this is where the high current in useful as it will force to pack in the cell until it triggers that it is full and can no longer accept any more charging. Relationship; higher cell heat - high current! I guess that you can charge with a low current, but I would be very surprised if it gets up to the 80% charge capacity, no matter how long you charge them. You first get to experience this when you charge some of your older cells in one of these newer high current smart chargers. Try your cells after this and you will think that you have a new set of cells. You will get new life out of most of them...

Re: Best \'slow\' charger

I leave my cells in the C204F al the time. It fast charges them, then goes in to "trickle" charge mode. I have three sets I use in my digital camera so one set in the camera, 1 backup and one in the charger. It seems to work really well for me.

Re: Best \'slow\' charger

OK, I think I'm convinced to NOT get this slow charger. So, does anyone recommend a AA charger that will charge cells individually and goes into 'trickle' charge mode?

Re: Best \'slow\' charger

Originally posted by Brock:
I leave my cells in the C204F al the time. It fast charges them, then goes in to "trickle" charge mode. I have three sets I use in my digital camera so one set in the camera, 1 backup and one in the charger. It seems to work really well for me.

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<font size="2" face="Verdana, Arial">Brock, I do exactly the same thing, with the same charger. One note of caution for you. We had a power flash the other night. Somehow that reset the charger and it started charging at full output. The batteries were already charged, but it stayed on full charge rate. I noticed it later that evening, and the batteries were very hot, so I unplugged the charger and removed the batteries. I put the batteries in and plugged the charger in the next day, and everything worked normally.

Re: Best \'slow\' charger

I think if you already have it, the C204F is a great charger. If you need a tiny charger (Like for travel) it's a great charger. If you are looking for a charger for home use, there are better chargers...

Many people are happy with the C Crane quick charger. I don't like the fact that you have to wait for your 1 AA to charge all the way before you toss in some AAAs or what not, but that seems to be it's only bad point...

I personally have the C204F and quite enjoy it, but it has gotten brainfreeze on me more than once...

Re: Best \'slow\' charger

I love my C Crane - does a very good job of charging near dead batteries ( usually single AA NiMH in my case for an Arc LS ) . Battery is charged in little more then an hour and is not hot. Only problem I have had with it is sometimes overcharges ( at least the battery get hot ) if the battery has 3/4 strengh when starting the charge.

Re: Best \'slow\' charger

and the ccrane has the battery drainage button and voltage readout, so you can bring down the voltage if you want to, before charging up..
But I love my new regulated power supply, I choose the current, and the voltage, one aaa, or a dozen D's -- I got yer charger right here..

by the way - my old unused maha777 makes a nice holding stand for the charging batteries, if nothing else..the magnetism that holds the battery in place extends out to the charger electrodes, so they just 'stick' to the ends of single cells..I imagine you could just set a single battery on any strong magnet and get the same effect -- no battery case needed..

Re: Best \'slow\' charger

I just got the Ray-O-Vac PS4 and tested the power bump theory. The charge light came on for just a few minutes and then shut down. The cell was just warm. So far I love this charger. Seems to pack in more power than my old & slow eveready whatever.

Re: Best \'slow\' charger

Oops, forgot to say that it says you can leave the cells in after charging and a trickle charge will keep you happy and healthy and make you look real handsome too. (Ok, maybe I exagerated a little but did I say that I love this charger?)

Re: Best \'slow\' charger

OK, I'm confused. I read on the ccrane website that their charger charges 1-4 batteries and also says it charges in parallel. But, it also says:

Q: Can I mix and match different sizes of batteries?
A: No. The problem with using different battery sizes is that the QuickCharger meters the voltage entering all four cells and begins the charging process based upon the average voltage. Mixing may cause some batteries to be over-charged or under-charged, but you can charge one battery at a time.

So does this mean If I have devices that use 1 cell at a time I'd have to charge them 1 at a time? Sounds like it unless I again 'match' them, in which case I may as well use a series charger? Right?

Re: Best \'slow\' charger

Originally posted by sflate:
OK, I'm confused. I read on the ccrane website that their charger charges 1-4 batteries and also says it charges in parallel. But, it also says:

Q: Can I mix and match different sizes of batteries?
A: No. The problem with using different battery sizes is that the QuickCharger meters the voltage entering all four cells and begins the charging process based upon the average voltage. Mixing may cause some batteries to be over-charged or under-charged, but you can charge one battery at a time.

So does this mean If I have devices that use 1 cell at a time I'd have to charge them 1 at a time? Sounds like it unless I again 'match' them, in which case I may as well use a series charger? Right?

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<font size="2" face="Verdana, Arial">Sounds like a bad design to me. I'll second the rayovac charger, for me it's worked far better than the Maha I used to have. They make one that will charge 4 AA's at a time, senses each one individually, switches from fast to trickle charge - it just works great. Plus you can buy at walmart for less than many of the other chargers that cost 2x as much.

I have 2 eveready chargers too, which charge up to D size batteries. They work in 2 sets of 2, though, so the batteries have to be used and charged evenly. When I looked, only Maha and Rayovac had chargers that would do a set of 3 batteries.

Oh, a nice thing about both the battery company battery chargers is that they will NOT hurt the batteries if they're left in for long periods of time. Coincidence? I think not.

Re: Best \'slow\' charger

quote--
They make one that will charge 4 AA's at a time, senses each one individually, switches from fast to trickle charge - it just works great

Thats pretty good if it tests and charges each indiviually - usually only the most expensive chargers do that

Re: Best \'slow\' charger

the crane works ok with cells in different states of charge, so long as they are all the same sized cells..the more charge a cell has the more resistance it has, so extra currents 'spills over' into the less-charged batteries..of course it helps if they are all roughly near the same state of charge, but they don't have to be exact...and I have yet to find hot cells in the crane..

Re: Best \'slow\' charger

Originally posted by dark star:
quote--
They make one that will charge 4 AA's at a time, senses each one individually, switches from fast to trickle charge - it just works great

Thats pretty good if it tests and charges each indiviually - usually only the most expensive chargers do that

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<font size="2" face="Verdana, Arial">Absolutely does - and it's great. I have a small ham radio that uses 3 AA's, which is why I bought the charger. It charges each battery, but they don't change from fast to trickle charge all at the same time. Close usually, but not the same time. I can mix battery sets, full and partial, and they'll all charge correctly. Coolest charger I have.