Spice Cat Posted December 19, 2010 Share Posted December 19, 2010 Being about as electrical as a box of matches; please can I have your ideas on the following; Can I connect a 12v gel battery and a 12v lead acid in series to produce 24v. Is this safe? PS This is for a trial run only of a geared starter. Quote Link to comment Share on other sites More sharing options...
birdy Posted December 19, 2010 Share Posted December 19, 2010 I've no idea why it wouldn't work... Quote Link to comment Share on other sites More sharing options...
Tony Smith 7 Posted December 19, 2010 Share Posted December 19, 2010 It would work and not be dangerous for a test at least. For longer use, a flooded lead acid battery and a gel battery may well have different characteristics so you could find that running them down, one gets over-discharged. Quote Link to comment Share on other sites More sharing options...
flytilbroke Posted December 19, 2010 Share Posted December 19, 2010 I agree with Tony. Quote Link to comment Share on other sites More sharing options...
Spice Cat Posted December 20, 2010 Author Share Posted December 20, 2010 Thanks for the help. I'm off until new year and will try this out tomorrow. Quote Link to comment Share on other sites More sharing options...
Spice Cat Posted December 20, 2010 Author Share Posted December 20, 2010 Well, the shed is still intact! Worked a treat! I will now get a couple of 11.1v Lipos to do the job. Thanks again. Quote Link to comment Share on other sites More sharing options...
Spice Cat Posted January 8, 2011 Author Share Posted January 8, 2011 Just to let you know, two 11.1v lipos arrived in the post yeaterday. They were duly fitted with 60a connectors and into series. Said assembly was fitted to the electric starter. Spun her up and the damn thing nearly took off. This could be classed as my first real leap into the el*ctric world. PS This is the first time I have charged Lipos and used the free Logic RC charger that came with the subscription. Worked a treat (although I did hide under the bench when I switched it on.) Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted January 8, 2011 Share Posted January 8, 2011 Well done SC. What model is that starter going to power then? Quote Link to comment Share on other sites More sharing options...
Wingman Posted January 8, 2011 Share Posted January 8, 2011 SC be careful you don't over-discharge your lipos being as you are connecting them direct to the starter - easy to do if an engine is being 'difficult'. Quote Link to comment Share on other sites More sharing options...
Spice Cat Posted January 8, 2011 Author Share Posted January 8, 2011 This will be firing up my 1.20 Piper Cub. I have recently modified the underside to accept a small digital camera, 5mp from ebay for £20. Hopefully I will be lofting it soon, weather and work permitting. Thanks for the info about over discharge. I am willing to make some errors in the early days but I will get a battery guard/checker. Funnily enough, I received an e mail from Hobby King stating they had identical batteries for £6.99 each. Quote Link to comment Share on other sites More sharing options...
John Privett Posted January 8, 2011 Share Posted January 8, 2011 Posted by Spice Cat on 08/01/2011 21:41:22:Funnily enough, I received an e mail from Hobby King stating they had identical batteries for £6.99 each. Actually better than that (assuming I got the same email this morning.) It was $6.99 (dollars not pounds) although the price was only available for 6 hours - so too late now. Quote Link to comment Share on other sites More sharing options...
Spice Cat Posted January 8, 2011 Author Share Posted January 8, 2011 Just had another look at my Blackberry. Dead on the money John, hopefully they will have a similar offer soon. Most people I speak to rate them highly. I have sent off for a windsock as a "test" purchase. Quote Link to comment Share on other sites More sharing options...
Spice Cat Posted January 10, 2011 Author Share Posted January 10, 2011 Used the set up to start my Jen .91 two stroke today. Trouble war, it span so fast the throttle was set so the engine was actually running slower that the starter. Still, worked a treat. Quote Link to comment Share on other sites More sharing options...
tom clarke Posted January 9, 2012 Share Posted January 9, 2012 hi people.. im doing my first large 3d model and need help with batteries, i have two identical 6v 3300 nimh packs to go into the plane, can i have one as a back up or how do i run both packs safely? (plane is 50cc sbach with 5 savox 20kg digis hence the need for lots of battery power) i know lipo is the way to go but never had a problem with nimh and the plane balances with both packs upfront. Quote Link to comment Share on other sites More sharing options...
Pete B Posted January 9, 2012 Share Posted January 9, 2012 Posted by Spice Cat on 08/01/2011 22:21:00:Just had another look at my Blackberry. Dead on the money John, hopefully they will have a similar offer soon. Most people I speak to rate them highly. I have sent off for a windsock as a "test" purchase. I'm thinking of sending my HK windsock back, SC - it sits there doing nothing in a dead calm and when it does blow, it always points in the wrong direction! Pete Quote Link to comment Share on other sites More sharing options...
Spice Cat Posted January 9, 2012 Author Share Posted January 9, 2012 I'm thinking of sending my HK windsock back, SC - it sits there doing nothing in a dead calm and when it does blow, it always points in the wrong direction! Pete We have the same problem at our strip. Wind blowing fine for flying; Roy puts his windsock up and, yes, wind swings through 90 degress to blow across the strip. They should be banned. Quote Link to comment Share on other sites More sharing options...
John Cole Posted January 10, 2012 Share Posted January 10, 2012 Tom: It is possible to do this and prevent one pack discharging INTO the other if that one develops a fault. You would need to put a diode in the wiring from each pack. You would best use Schottky diodes as they have only about 0.3 volt drop. Look for diodes with a 50V rating and you may need to put two (or more) in parallel on each side to carry the current: look at the ratings for the diodes. They cost just pennies. I would put all this in a Y-lead, and test by connecting just one battery at a time, shorting the plug for the second one with e.g. a wire including a low-current fuse (no significant current should pass) . The Rx etc. should be unaffected and continue to work when you do this. Test BOTH sides. Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted January 10, 2012 Share Posted January 10, 2012 @Tom Clarke.... Or buy one of .these..... Johns suggestion is cheaper though.....bear in mind that you would nned to bypass the diodes for charging the batteries however.... Edit.....knew I'd seen a cheaper version here Looks suspiciously like the PB one too....Edited By Steve Hargreaves on 10/01/2012 15:55:03 Quote Link to comment Share on other sites More sharing options...
tom clarke Posted January 10, 2012 Share Posted January 10, 2012 thanks lads, il start working on the batteries soon. Quote Link to comment Share on other sites More sharing options...
John Cole Posted January 10, 2012 Share Posted January 10, 2012 Steve: good point about charging. Separately: I said use 2 or more to carry the current. I SHOULD have said to carry the FULL current, assuming one battery has gone U/S. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted January 10, 2012 Share Posted January 10, 2012 Funny way for the thread to go - it started off as a series question and has evolved to a parallel one! Quote Link to comment Share on other sites More sharing options...
DH 82A Posted January 10, 2012 Share Posted January 10, 2012 Its gone into a parallel universe Quote Link to comment Share on other sites More sharing options...
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