Neil James Posted November 10, 2020 Share Posted November 10, 2020 Having had a recent sort out I’ve discovered I have a couple of multi port chargers which I used to use to charge up my NiCad equipped models as they could then be left on trickle charge until the next flying session. I’ve been using a modern lipo charger with peak detect to top up batteries while driving to the flying site but I now have a new shed where I can store models in a way that makes them accessible for a permanent charging solution and the question is, can I use these chargers designed for NiCads to charge and maintain NiMH, given the differences in voltage and chemistry? I have used them to successfully charge NiMH packs recently but not used the long term trickle charge feature so would be interested to hear other users’ experience. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted November 10, 2020 Share Posted November 10, 2020 Can't see any reason for not using it to trickle charge nimh; myself, I trickle my 2Ah (ish) eneloop RX packs at about 120mA. Modern nimh do not lose charge as much as the older nicd used to, so leaving them on permanently is not so desirable. Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted November 10, 2020 Share Posted November 10, 2020 Doesn't sound like a good idea according to Battery Universe Quote Link to comment Share on other sites More sharing options...
Maurice Dyer Posted November 10, 2020 Share Posted November 10, 2020 Neil, I have the same charger. Charges my Nimhs perfectly. Maurice Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted November 10, 2020 Share Posted November 10, 2020 Like Maurice said, I also have a Robbe charger like that - though an earlier model - and it trickle charges NiMhs perfectly well. Personally I wouldn't leave the NiMhs on from one flying session to the next, for days on end, just trickle charge them for up to 12-14 hours if flta, then check them with a battery checker under load. Modern Nimhs and Eneloops don;t self discharge anywhere near as quickly as the older ones did. Quote Link to comment Share on other sites More sharing options...
Maurice Dyer Posted November 10, 2020 Share Posted November 10, 2020 I know everything new is brilliant; and old fashioned is rubbish. BUT, I still charge my batteries the good old fashioned way. C/10% for between 8 and 12 hours. Never had a battery fail me in the 40 years of old fashioned flying. If you ever get the chance, read the 1972 Radio Modeller Propo manual. Having said the above. New stuff (Lipos) are brilliant. As are Eneloops. Horses for courses. Maurice Quote Link to comment Share on other sites More sharing options...
Peter Christy Posted November 10, 2020 Share Posted November 10, 2020 Whilst a thorough trickle charge once in a while helps to balance a NiXX pack, doing it continually is not a good idea. Very few flyers use anything like the full capacity of a pack in a day's flying, and therefore charging at 0.1C for 10-12 hours will result in the battery being regularly overcharged. Overcharging will warm up the battery, possibly drying out the electrolyte, though at 0.1C, this is not the major problem. What will certainly happen is that the cells will start to vent gas. The gas is alakaline and corrosive if there is any damp in the atmosphere. This is the root cause of the dreaded "black wire" corrosion. It is no coincidence that "black wire" corrosion has almost disappeared since the introduction of "peak detect" chargers. The short answer is that occasional use of a trickle charger will do no harm, and may be slightly beneficial. Continual use is not a good idea! -- Pete Quote Link to comment Share on other sites More sharing options...
Maurice Dyer Posted November 11, 2020 Share Posted November 11, 2020 Well now, that's interesting. Everything I have ever read on battery technology tells you never to peak detect any Nimhs or Nicad because of the false peak you get. And I even proved it to myself. But I have never peak detected the newer LSD type like Eneloop. Maurice Quote Link to comment Share on other sites More sharing options...
Nigel R Posted November 11, 2020 Share Posted November 11, 2020 Not sure of your sources Maurice, but peak detect is a well proven thing. The caveat with nimh is that around 0.5C the peak is quite weak; if the pack is also unbalanced, that can be a difficult condition for the charger to cope with. As a second point, regarding trickle time, I have found that an average glow flight (for me) uses about 80mAh from a nimh pack, I trickle for an appropriate time (about 1hr per flight at 120mA, in my case) to replenish that without going overfull to the point of simply heating the cells. Your numbers may vary, depends on trickle rate, how you fly, etc etc. You could use any of our lipo chargers to measure the charge needed to refill a pack - only needs doing a few times to establish how much your own flights use. Nicads would self discharge quite quickly. An overnight trickle was a simple panacea for that problem (although as Peter notes the dreaded black wire was much more prevalent). Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 11, 2020 Share Posted November 11, 2020 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
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