Steve Goodwin Posted February 14, 2014 Share Posted February 14, 2014 I have decided to fit the SHM Advanced Glow System which obviously needs a power source. The battery from SHM was a bit dear so I thought I could make my own, seemed simple at the time? Anyway, I need between 1.2v ~ 4.2v at around 1500 mAh for my requirements, so my question is can I solder two of these link together to give me 3.7v at 1600mAh? Or is there an easier way, I need to beware of the weight implications, your help is much appreciated, Steve. Quote Link to comment Share on other sites More sharing options...
jack lackmaker Posted February 14, 2014 Share Posted February 14, 2014 .cannot see any reason why not just solder them positive to positive negertive to negertive Quote Link to comment Share on other sites More sharing options...
Steve Goodwin Posted February 14, 2014 Author Share Posted February 14, 2014 That's kind of what I was thinking Jack, just need to make sure I do it safely. Like my Grandad used to say measure twice cut once! Quote Link to comment Share on other sites More sharing options...
Andy Butler Posted February 14, 2014 Share Posted February 14, 2014 Steve, I'm planning to install a SHM glowdriver in the Cub. For the power supply I got a 2 AA holder from Maplins and plan to use 2 AA rechargeable 2500mAh cells from the same place. I figured that this will allow plenty of capacity and they can be charged in the model - as long as I don't forget. Since the engine (RCV 58cd) is entirely within the cowl a normal glow driver can't be used. Just a thought. Quote Link to comment Share on other sites More sharing options...
Toni Reynaud Posted February 14, 2014 Share Posted February 14, 2014 Just curious - will 2300 AA rechargeables (even two in parallel) provide enough current without the voltage dropping too low? I was under the impresion that a 2300 cell won't really deliver high current and that they are only reeally suitable for transmitter power supply or other low current tasks. How much does a glow plug take? Quote Link to comment Share on other sites More sharing options...
Steve Goodwin Posted February 14, 2014 Author Share Posted February 14, 2014 Andy, that's the reason for me using the Onboard glow, can't fit the glow stick because of the cowl. Have you checked the output voltage on these batteries, I just had a quick look on the Maplins site and the ones I found only have an output of 1.2 v, which is standard for a AA cell, this would NOT be enough voltage to drive the AGS, even doubled up. Just a thought Which I think where Toni is coming from? Edited By Steve Goodwin on 14/02/2014 13:30:39 Quote Link to comment Share on other sites More sharing options...
Stevo Posted February 14, 2014 Share Posted February 14, 2014 I'm not sure of the logistics, but I would fit a remote glow ? 1.2V is standard for a NiMh, as used on glowsticks. However the circuitry may require a little more to regulate the current etc. 2300MaH gives no indication of maximum current that can be delivered, however I have used onboard glow drivers with 2300Mah batteries that have lasted, and lasted, and lasted... Not sure of exact plug current - let's say for ease of calculation it's 1A... with a capacity pf 2300Mah, it would (theoretically) keep it glowing for 2.3Hrs.. Quote Link to comment Share on other sites More sharing options...
Steve Goodwin Posted February 14, 2014 Author Share Posted February 14, 2014 Stevo, agreed. But the SHM kit requires an output voltage of 1.2v~4.2v the capacity of the output device is not at question here. Running this system with output voltage of 1.2v (standard AA cell) is on the edge to say the least. Quote Link to comment Share on other sites More sharing options...
Steve Goodwin Posted February 15, 2014 Author Share Posted February 15, 2014 Anyone here? Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted February 15, 2014 Share Posted February 15, 2014 Steve those batteries should be fine......soldering them together (positive to positive & negativer to negative as suggested earlier) will in effect connect them in parallel thus maintaining the voltage at 3.7 volts & doubling the capacity to 1600mAh. Solder the SHM kit & maybe a charging lead to the battery terminals, wrap in tape or heatshrink to supportr the wires & you should be good to go. DO remember to use the correct setting on your charger when charging these batteries though won't you. Quote Link to comment Share on other sites More sharing options...
Steve Goodwin Posted February 15, 2014 Author Share Posted February 15, 2014 Steve, I did get the charging lead, but I'm not sure if the charger I have has that connection. The lead supplied by SHM is the same as the lead you would use to charge a Tx? Quote Link to comment Share on other sites More sharing options...
Shaunie Posted February 15, 2014 Share Posted February 15, 2014 A typical 1.2/1.5V glowplug draws in the region of 4A! Assuming your glow controller is a switch mode animal (which it probably is) that converts to a draw of about 1.6A at 3.7V allowing for 20% losses. This will give you a run time on glow of about 1 hour, the controller will not be driving the plug at all throttle settings so this will of course increase your effective run time. You could use a 18650 Li-ion battery or batteries (standard laptop cell size), these are available at around 4000mAh if you feel the need for a huge run-time. I use these in a hand torch with a plug in the wall charger bought from ebay at a ridiculously cheap price. You would need to use a battery holder so you could remove them from the plane for charging. Many generic flight chargers do not have a Li-ion setting, I know my Ripmax one doesn't, I've just checked. Here's the remote glow on my Edge. The top hole is glow, the bottom is the fuel fill. Sorry about the rotation, should have turned the image before uploading it! Quote Link to comment Share on other sites More sharing options...
Stevo Posted February 15, 2014 Share Posted February 15, 2014 4A? I was waiting to see who spotted my deliberate mistake. Shaunie - that's exactly HOW you install a remote glow and remote fuel nozzle. I've done it like that a few times on various models on its own plate like yours - nice one. Quote Link to comment Share on other sites More sharing options...
Shaunie Posted February 15, 2014 Share Posted February 15, 2014 Took me a while but I spotted it in the end . Thank for the compliment, I was quite pleased with it myself, otherwise I'd have kept my gob shut! Luckily I had a length of stainless angle of just the right size. Shaunie Quote Link to comment Share on other sites More sharing options...
Steve Goodwin Posted February 15, 2014 Author Share Posted February 15, 2014 Shaunie, that is nice and neat, very tidy. The system that I have chosen from South Herts Models (which has a fairly good report from guys on here) does not suggest anywhere near the battery pack you suggest, please don't assume I am questioning your advice I'm just a bit confused. the spec sheet is here cheers Steve Quote Link to comment Share on other sites More sharing options...
Fatscoleymo Posted February 15, 2014 Share Posted February 15, 2014 Steve - I've used SM Services on board glow drivers for eons - they work very well and I use a 1.2v sub C nimh of 3800ma. Always been way more than adequate for a days flying. I suggest you put a small on off switch in the circuit on the outside of the aircraft ( I have one underneath my Cub just behind the cowl), so that you can make sure the glow can not be energised before you want it to be - ie when your tranny is on and you're preparing to start and the throttle might be at low setting. I assume it works at low throttle settings? However I've just programmed my Taranis tranny to use a 'remote receiver controlled switch' ( bought from 4 Max for about 9 quid) and now I have just that and the sub C doing the same job, with with the advantage of being able to switch it on and off from the tranny as well. I love my Taranis! Steve Quote Link to comment Share on other sites More sharing options...
Steve Goodwin Posted February 15, 2014 Author Share Posted February 15, 2014 Cheers Steve, that's a large capacity cell, who supplies them? The min req on the spec sheet is 1.2v and you have found this to be ok? cheers Steve Quote Link to comment Share on other sites More sharing options...
Steve Goodwin Posted February 15, 2014 Author Share Posted February 15, 2014 BTW Steve who are SM Services? Quote Link to comment Share on other sites More sharing options...
Fatscoleymo Posted February 15, 2014 Share Posted February 15, 2014 Here's the link to SM Services: **LINK** They do a sub C cell, but many others as well, Overlander, etc. Model Shop Leeds is where I bought mine. The sub C has always been fine - never a problem. Steve Quote Link to comment Share on other sites More sharing options...
Steve Goodwin Posted February 15, 2014 Author Share Posted February 15, 2014 Seems that it's the only item in the list that can't be ordered. Quote Link to comment Share on other sites More sharing options...
Shaunie Posted February 16, 2014 Share Posted February 16, 2014 Hi Steve, no worries I didn't mean to confuse. I just wanted to give reasonable figure for expected run time. If the glow only operates at low throttle and maybe tapering off towards mid throttle then in actual flying terms that would equate to maybe 2 hours in the air. I don't know how much airtime you get in a session but that is way more than I would do! I only suggested the bigger size because of ease of charging and my tongue-in-cheek comment about a HUGE runtime . Basically it was a suggestion, not a recommendation. A 18650 is only about 50% longer and 25% fatter than an AA cell by the way. I took a comparative picture but the site won't let me attach it at the moment, the "insert image from album" box is blank. Shaunie. Quote Link to comment Share on other sites More sharing options...
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