Masher Posted March 7, 2014 Share Posted March 7, 2014 SHORT VERSION: If you have one of these from Ripmax, be careful how you use it! LONG VERSION: My Mini Jazz lost one of its lives today but fortunately survived Ok. Some time ago I bought the Ripmax multi-charger to simplify the charging of multiple Plane receiver batteries. This unit reduces wires and mains connections and being delta-peak, it reverts to trickle charging once batteries are fully charged. I had a day of flying the Mini Jazz Wednesday so quickly put it on charge when I got back. Went out again today with model fully charged (NOT) as indicated by green for go on charger. 8 minutes in and control was very irratic but responded to throttle down and somehow I got it down with no damage. On the ground, servos were a mixture of still and twitching and Rx not responding to Tx. However, after leaving rx off for 5 mins then switched on - bound Ok and control Ok for about 30secs - then died again. This indicates a battery issue. Back home I put my other 2 planes on charge and noticed that the charger showed red (full charge) for only 30 secs or so - indicating fully charged. As I had flown the WOT 4 for an hour today this couldn't be true. Switched off at mains and back on then red light stayed on and has now been on for over an hour! To cut a long story shorter, this charger is inclined to get itself in a twist and can instantly go into trickle (or even off for all I know). It seems that if you don't unplug from mains each use, the timer/detector don't work. I'm not going to do any tests and there is no point in contacting Ripmax - I've tried that in the past and wasted my time. This one will go in the bin as it can't be trusted Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted March 7, 2014 Share Posted March 7, 2014 That can be a problem with delta peak chargers, sometimes batteries have a false peak, especially if the charge rate is fairly low, which tricks the charger into thinking they are fully charged when they aren't. So it's always best to check the battery on a battery tester regardless of the charger used, or have a charger which tells you how many mah it has put back in then you have a measure of how much charge it has taken. Using telemetry to monitor receiver volts means I don't have to worry about this too much, recently I arrived at the field without the Rx battery a fellow flier lent me a fully charged up battery, but the telemetry alarm went off before it even got off the ground, maybe he had similar charging problems. Quote Link to comment Share on other sites More sharing options...
Masher Posted March 7, 2014 Author Share Posted March 7, 2014 Yes Frank I agree. I also have an issue with the battery tester too - this has to be done under load. I think I will revert to using my clever chargers which indicate how many mA have been replaced! Quote Link to comment Share on other sites More sharing options...
Paul Marsh Posted March 7, 2014 Share Posted March 7, 2014 I also like to see how much charge has gone in. For example, I had an old 650 mah Nicad pack and put that on charge. I saw how much it put in and although the battery was almost flat, put a good charge in. Chargers like yours put blind faith before faith, even that is no good. Quote Link to comment Share on other sites More sharing options...
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