John Lee Posted March 10 Share Posted March 10 I've still got a Hitec Powermate II which was a popular battery checker before LiPos came into common use. That puts a load of 0.6amp at the 4.8v setting & 0.8amp at the 6volt setting. Futaba produced the BR-2000 checker at the time which also could load up the battery. 1 Quote Link to comment Share on other sites More sharing options...
steve too Posted March 10 Share Posted March 10 2 hours ago, Robert Cracknell said: I have a number of Ni-Mh cells that I would like to check out more thoroughly. ... What is your favourite method? I periodically cycle my NiMH packs on a decent charger discharging at around 1C and charging at around 0.75C. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted March 10 Share Posted March 10 30 minutes ago, steve too said: I periodically cycle my NiMH packs on a decent charger discharging at around 1C and charging at around 0.75C. Do I need a Tandem for my Tug, as it has 2 batteries in it ?😂. Quote Link to comment Share on other sites More sharing options...
Phil Green Posted March 10 Share Posted March 10 The battery voltage is less important than its ESR which limits the current it can supply, in fact a high-ESR pack can show an artificially high unloaded terminal voltage. For example many of us run flight packs off a single Lithium cell, its a lower voltage than a 4.8v NiMh but has such a low ESR that the terminal voltage is maintained over wild variations in current draw. At the other extreme are those whose solution to a 4.8v pack that drops under load is to add another cell in series. This really is very poor practice, no engineer would fix a current supply and hence a voltage drop problem by raising the voltage, in fact an additional cell increases the already poor ESR by 25% and the % voltage drop for a given current will actually be worse. Power supply problems are best fixed with a low ESR high quality pack, not by upping its voltage in the vain hope that the extra cell will 'fill in the gaps' 👍 [/2p] Cheers Phil 4 Quote Link to comment Share on other sites More sharing options...
Geoff S Posted March 10 Share Posted March 10 (edited) sorry posted in error - dumb thumbs again! Edited March 10 by Geoff S Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 10 Share Posted March 10 I discussed this with George at 4-Max and suitable solutions for me is to use a high current UBEC or power distribution boxes. Both or these are supplied from 3S2200 lipos which has a couple of advantages. Firstly I use 3S2200 batteries as flight packs which means they get a good performance discharge (way beyond the sort of load a RX/servos would exert in normal use) so I know they will perform when I need them to. Secondly with a high current UBEC I won't get a brown out on the RX if a servo fails or jams as the UBEC can supply more than enough current. Works for me, but I am sure there are a few die hard that would argue differently. 1 Quote Link to comment Share on other sites More sharing options...
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