Originally Posted by Rodney

Weidmark, your computer power supply is capable of the 15 amperes but, it may require that you put a load on the 5 volt buss as well in order to get the 15 amperes on the 12 volt buss. Most computer supplies (at least the older ones) get their regulation off the 5 volt buss and, it it is not loaded, will not provide full output on the other buss's. If you can not get the high output off the 12 volt buss, just put a 5 ohm 10watt or higher resistor on the 5 volt buss and see if that lets you draw more current off the 12 volt buss

You need to check the spec sheet for the PSU. Some older ones required a 50% load on the +5, many newer ones only require an amp or two.


Mike

Many of the higher power chargers will run from 11 volts or so. As for your existing problem , it cannot be the ps.

Originally Posted by weidmark

I believe the charger I received was faulty. With this charger, when I start it up, it will give me the current voltage of the battery that is being charged, then it will immediately change to 8.4V and begin charging the pack. It charges a 2S pack to 8.25V

I just charged a battery and this is what I got. 2S 5300mAh Gens Ace.

Started at 6.9V and initially was charging at 3.2A
After 10 minutes charging at 2.2A
After 30 minutes charging at 1.9A
After 60 minutes charging at 1.7A
After 90 minutes charging at 1.5A
After 135 minutes charging at 1.1A
After 170 minutes charging at 0.6A

This was using the computer PS

Charge finished at 212minutes and put 4722mAh into the pack.

What is the output voltage as reported by the charger when it begins tapering current? If it shows cell count x 4.2 volts, you then have a high impedance somewhere in the output chain. This could be within the charger, the charge lead or connections, or the battery itself. You'll have to rotate parts to further isolate, ensuring that you only change one variable at a time so you can isolate the culprit.

Mark

I think the charger is the problem. I will test charging vs another accucel 6 later tonight.

I think I am going to pick up an icharger 106b. I would like more reliability when im charging and 10A should be plenty for me.

Originally Posted by weidmark

I think I am going to pick up an icharger 106b.

Very wise decision. In my experience, there is no better charger in the sub-$100 range.

Mark

So I got my friend's accucel 6.

with a gens ace at 7.80V i started charging with mine, and it was charging at 1.3A. I swapped his in and I still got 1.3A. I swapped power supplies, and banana cables and i always got 1.3A.

So i really do not know what the problem is. My concern now is if I get the icharger, will I be limited to this low charged rate still? Considering the accucel should be able to charge faster and I am getting the same result on two of them.

What was the voltage readout on the screen after you started the charge and the current rose to 1.3A?

On both chargers it reads 8.4v

...and there's your answer.

Your charger is immediately entering CV mode due to high impedance in the charger output chain. You either have a bad charge lead or a bad battery, plain and simple.

If it's voltage drop in the charge lead, an iCharger will indeed charge faster as they compensate for charge lead voltage drop. However, the fact that you have .6V drop at 1.3 amps points to a rather significant issue with your battery or your charge lead.

Mark

Originally Posted by mrforsyth

...and there's your answer.

Your charger is immediately entering CV mode due to high impedance in the charger output chain. You either have a bad charge lead or a bad battery, plain and simple.

If it's voltage drop in the charge lead, an iCharger will indeed charge faster as they compensate for charge lead voltage drop. However, the fact that you have .6V drop at 1.3 amps points to a rather significant issue with your battery or your charge lead.

Mark

Oh I see!

I just found some 10AWG wire in the garage and soldered it to some banana plugs and voila. Now I am getting 5.3A charge rate.

Thank you all for the help.

Yay!

Mark

Yea. The only thing I dont understand is why the thin yellow 12v wire in the PSU is fine, but the thin charge leads cause problems.

I think ill still get an icharger, although ill probably wire 3 or 4 of the yellow wires in the PSU for this.

Your input may handle a 2 volt drop without any consequence , but with a cv limit of 8.4 volts ANY drop shows up as a current drop (hitting the cv early) 16 gage wire should be adequate. Sounds like your good to go anyways.

One of the nice features about higher quality chargers (FMA, iCharger) is that they will compensate for charge lead voltage drop when balance charging. This allows them to stay in CC mode for a much longer time than lesser chargers and thus have shorter charge times, even when charging at the same current.

One of the many reasons why recommend nothing less than the 106B+.

Mark

Originally Posted by mrforsyth

One of the nice features about higher quality chargers (FMA, iCharger) is that they will compensate for charge lead voltage drop when balance charging. This allows them to stay in CC mode for a much longer time than lesser chargers and thus have shorter charge times, even when charging at the same current.

One of the many reasons why recommend nothing less than the 106B+.

Mark

Good to know. Looks like that will definitely be my next purchase. Are the the ones sold at hobby king authentic? Or am I better of getting one from progressiverc