We've just flown with a multistar 10,000 and it flew very well. Gave us all 10,000 mA at 6S at 5 amps. 1hour and 15 in the air.
When we went to charge it at 5 amps, we killed two I charger 208Bs and then blew up the power supply.
Something's not right. Battery was not hot. Cells are all balanced. Charger was not hot.
Can't work it out. Is there a trick to charging big batteries?
Replies
I'm wondering if the problem is actually the ripple current. I believe that when a charger is sitting on it's amperage limit, it's not a steady current, but pulsing on/off and just averaging the steady rate. High capacity batteries might have a 10% on/90% off duty cycle, compared to a 50/50 cycle of a small battery. During the 10% on-time, the current is very high. This leads to a high ripple current, which places the charger's caps under high load. They heat up, and can fail. Long charge leads would make this worse.
Just a theory. But it's basically the reverse of what happens in an ESC.
It's interesting that it happened to an iCharger, which are supposed to be a really good brand name.
I've charged MS 4s 10A batteries dozens of times with an I-Charger 206B at 1C (10A), and a 8000 4s non-MS at 2c without issue. The power supply is a 500W Antec from a computer rated 18A @12v. Nothing fancy, but it works.
My guess is either the settings were wrong or the power supply is bad. Two bad 208B's in a row? Doubtful.
DG, Charging settings were correct. We were only charging at 5 amps. It was TWO i208bs and TWO 1000W power supplies. The only common denominator was the battery.
I have hundreds of cycles on large batteries (6s 5-10Ah) at max current (~16A) using the HK dual 400w charger with no probs. Literally charging non-stop for 10-12 hours day. A good clean power supply is a must, And you should run at the highest input voltage your charger will take.
What's the power supply voltage and current ratings?
I use the same charger and their 1080w power supply and also have hundreds of successful charging cycles at 2x10A on those multistar 10AH and other large battery configs. I have parallel charger boards on both outputs and also charge pairs of 6AH batteries on each side.
http://www.hobbyking.com/hobbyking/store/__20613__Turnigy_MEGA_400W...
and
http://www.hobbyking.com/hobbyking/store/__20612__Turnigy_1080W_220...
I bought mine from the US location but provided the international links.
I replaced the fans in the charger with some high-quality PC fans after they started making noise but otherwise the charger has been fantastic.
OK, so;
1) No one else has had problems charging big batteries with the i208B
2) I use the same power supply as everyone else did.
3) I charged at 5 amps instead of 10 amps.
It HAS to be the battery!
There is no way it can be the battery if the charger is current limiting.
I've seen this same thing happen to three different chargers all sold by HK charging at or near the "rated" capacity of the charger. In each case the charger started a high pitched whistle followed by a very loud *POP* and then some smoke. I repaired one charger a club member gave me and attempted to use it to charge a 4S 6000mAh battery at 10A (battery was rated @ 2C charge rate) and after about 20 minutes the charger failed in the same manner as the other chargers.
The charger would work fine as long as you didn't attempt to charge anywhere near the "rated" capacity. I have no personal experience with this particular charger, but i would suspect the charger before I would blame the battery.
Regards,
Nathaniel ~KD2DEY
I don't think a battery can blow a charger...
If you blew 2 chargers and then the power supply..... it sounds like to me the power supply started acting up
and it blew the chargers and then it died itself... a battery can't do that...
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