Accupower LSD D & Vanson BC1HU

[VegasF6]

I recently purchased 12 accupower LSD D cells and 2 Vanson chargers. I got the chargers from battery junction. The problem with them is no matter which channel I use it seems completely random whether or not the charger reaches termination. I had a cell that never turned green, I marked it a bad cell, and moved on. Later the one's that did turn green, some of them decided not to. I put the "bad" one back in and it decides to turn green just fine. I expected if fully discharged that I may have to cycle these batteries twice, but these were fresh from the supplier, reading about 1.2v already. The ones that stayed on the charger got quite warm, and I have since learned that this probably means they are over charging. If I pull one from the green circuit, it reads 1.9V fresh off charger and the red circuit comes hot off charger at 1.8V. These #'s seem very high to me? They settle down to about 1.35 after awhile, which is much better.

The documentation included with the charger states charging D cells from 1200-11000mAh.

So, I pick up 4 Titanium brand C cells, 5000mAh. The charger works flawlessly with them. I then bought 4 accupower LSD c cells (they are 4500mAh) and I run into similar problems.

I can only conclude 2 things,
A: this charger doesn't like the higher resistance of LSD cells?
B: this charger is a piece of junk???

If I choose to monitor the charge and just pull the batteries when warm, I guess it is useable, but that isn't really realistic when it could be as much as a 10 hr charge time or more.

Oh yah, one more thing, I thought this charger was supposed to have a timer safety. Well not that I can tell, from either the docs or from function. It doesn have a 14hr timer for 9V, but they are charged by a simple dumb timer charge.

 

[Mr Happy]

Others with more expertise may chime in here, but I would guess it is a limitation of the charger. The minus delta-V charge termination test relies on a significant rise in cell temperature at the end of charge to produce a detectable signal. For this reason it is usually recommended to use a charge current in the 0.3C to 1.0C range. For a 10,000 mAh cell, 0.3C would be 3000 mA or 3 amps. The Vanson charger however is using 700 mA, or 0.07C. This is rather below the recommended range.

An interesting comparison can be made with the Sanyo MQN05 charger. This uses a relatively low charging current of 300 mA (IIRC), which would be 0.15C on a 2000 mAh cell. The instructions for this charger say that you should charge with the lid closed and in a vertical position attached to a wall outlet. I think keeping the lid closed traps heat inside and assists with producing a good -dV signal.

With the Vanson charger I would therefore also advise making sure to keep the lid closed when charging. You might further consider covering just the battery compartment lid with some aluminum foil (but don't prevent heat escaping from any vents around the electronic bits). Failing that, time the charge manually. A charge of 120% of rated capacity should usually be sufficient to fully charge a healthy cell. So 10,000 mAh would be 17 hours at a 700 mA charge rate.

 

[NA8]

I've got 4 of those D cells and 4 of the accupower lsd C cells. I've got the Maha MH-C808M charger, and I've had no problems conditioning and charging those cells. The beast is close to $90, but it seems to work well with AAA through D size batteries. The LCD display is a little screwy when the charger is switching over from discharge to charge mode, but that seems to be the worst of it so far. Some people complain that it doesn't put the last bit of mA hours into the batteries, i.e. it doesn't fully charge them, but I think the difference is negligible. It also doesn't run the battery temperatures up high which is nice. Anyway that's my plug why it may be worth the extra bucks to people.

 

[etc]

I've had Vanson BC1HU charger for a year and I like it. Very simple to use and cheap. Charges Maha and Eneloop AA and also CTA D cells and does take a long time.

I know you are asking about these LSD cells... I have no experience with these. I will probably get a better charger for these.

P.S. Vanson did fry one Maha AA cell but I suspect I kept the lid open which might have been the reason.

 

[VegasF6]

I have an old hobby charger from back in the day, it is an "Activator" that charges up to 6 amps. Problem is it only charges 4-8 cells. So, I will have to test that out when I have an even # of dead cells. Still, somewhat disapointing. Unrelated to these cells, I also just got the Soshine SC-S1 Li-ion charger. I cant decide if I like it, but I am leaning towards no at this point. I am not informed enough to review it properly, but I can tell you it continues to trickle charge. The 18650's I pulled off of it charged to 4.24V by the time I got to them, too high.

 

[mdocod]

Mr. Happy nailed it on the head, the charging rate is too slow to generate a strong enough signal to terminate. I have had this charger for a few years now and appreciate the value is represents, but it misses termination on 5AH C cells about 10% of the time, and misses it on 10AH D cells about 30% of the time or more. I think the suggestion to keep the lid closed *might* help, but I haven't personally observed any difference in termination reliability lid opened or closed. For AA cells this charger is awesome. If I had a larger collection of Cs and Ds I would invest in a MAHA 808 as it has a 2A charging rate, which should be high enough to nearly eliminate missed terminations.

 

[VegasF6]

Well thanks very much for the replies. I suppose I should have asked this before I bought it, not after. But, it will still have some use I suppose, just not entirely sure what.

 

[Mr Happy]

On the plus side, the 700 mA charging current is not going to do much harm to 5000 mAh C cells on overcharging, and even less harm to 10,000 mAh D cells. So if you calculate the charging time at 120% of capacity and manually stop the charge if it hasn't terminated by then, you will be fine.

The time to be really concerned about overcharging damage is if the batteries get hot hot hot. If they just get a little bit warm that's not much to worry about.