ProPeak SuperNova by Ripmax.

[djindivik]

Hi Guys, I bought my Supa Nova at Cosford a couple of years ago & have no idea who from, so i cant take it back to them. After finally figureing out the almost impossibly long flow chart,( i still have to look at the flow chart though), i started to be able to use it. Untill, that is, It cooked a couple of nice new expensive TX packs, 2500mah. When i tested the output, connected to a 12v battery with NO cells or programmes selected, it was banging out a good, hard, solid, powerful, 12v direct onto the output sockets. No wonder it was cooking my cells. So, my question is; anyone any ideas as to what has gone wrong ? Can i fix it ? Can it be fixed ? If it can, who can ? Ripmax ? Or who ? Oh sorry that was 6 questions, never mind. Any ideas guys, I know someone will know. Cheers. Ray

[arneansper]

Measurement of the output voltage without cells connected is meaningless IMHO. Even if you don't have any cells connected some chargers put out some voltage to detect when the pack is connected. Try to measure the voltage with some almost-but-still-not-completelty-dead pack attached.

Arne

[djindivik]

Hi Arne, Yes i tried that too, I understand that there would be a monitoring voltage put out to test the cells, but it is a good full strong & solid 12v that lights a car headlight bulb really bright when connected. In fact before i have chance to measure the voltage with cells connected, they are getting hot. Dont worry, you wont hear the bang from Estonia ! He he. Ray.

[arneansper]

Heh :)

I'm not an expert on chargers, but I did recently modify my own charger and did draw up the output stage. I had two poweful transistors that passed the charging/discharging current. The charging transistor was connected directly between battery and positive power supply. When this transistor is short-circuited the power supply is connected directly to the battery.

My guess is that this transistor is shorted in your charger. Perhaps some other components are damaged too. If it is only transistor then the fix would be quite simple for somebody with basic electronic skills. Of course, finding the cause of the fault (transistors do not ususally short circuit themselves) and checking for other malfunctioning components might take considerable time and if you have to pay for this, it would be costly. If feel comofrtable with the soldering iron, open the charger and look for obviously damaged components.

Arne

[guy mckenzie]

It will charge NiCds on the automatic programme but it MUST be set up manually to charge NiMh - as it says in the difficult to understand instructions you get in the UK. Some of the earlier ones peak detected NiMh early. Here is a USA manual, which helps

https://www.fmadirect.com/support_docs/item_1072.pdf

and Andrew Gibbs (Southampton) wrote a clear simple book on how to use it for about 6quid. His email is mrandrewgibbs@yahoo.com

I 'thought' I had a problem with mine and Ripmax Service were very helpful.

[Chippie]

PM sent.. :)
12v in and 12 out...Sounds like the charging mosfet is short circuit...That being the case, it would over charge.

Does the voltage rise when you increase the cell count ?