mightypeesh Posted May 29, 2015 Share Posted May 29, 2015 Hi folks. Been thinking about this for a while, and I am sure it is possible but I not sure which wire goes where. The charger for my cordless dremel has burnt out, and the price of a new one made my eyes water! I have a charger that can connect to Li-ion packs and my thinking is as follows. Identify the charging pins on the charger use my meter to establish positive and negative set my charger to 7.4v - the back of the broken charger says the output is 3.6 to 10.8 so that is in the middle. set my charger to 1300mAh - pack is 1.3Ah get rid of the existing leads and solder new ones directly to the pins within the old charger with connectors of choice charge as usual using the old dock for the battery. If my thinking is not flawed my questions are as follows. I have not used Li-ion packs before - do you balance them? The dock has four contacts - are two for charging and two for balancing? why does the pack have three contacts on the side when the charger only has two? My charger says on the front it can charge Li-ion, but when you scroll through the menu it seems to lump it in with Li-Po - is that correct? I hope you electronics wizards here can shed some light on this for me as it would be good to get it usable again. Please see photo's below of various bits. Many thanks, Simon. Quote Link to comment Share on other sites More sharing options...
Sparks Posted May 29, 2015 Share Posted May 29, 2015 Simon, An obvious question, so apologies if you have already investigated this. There looks to be a wired-in glass fuse on the left side of the charger PCB. Have you checked the fuse is OK? Regards, Richard Quote Link to comment Share on other sites More sharing options...
Dickw Posted May 29, 2015 Share Posted May 29, 2015 Posted by mightypeesh on 29/05/2015 08:37:28: ................... set my charger to 7.4v - the back of the broken charger says the output is 3.6 to 10.8 so that is in the middle. ......................................... I have not used Li-ion packs before - do you balance them? I hope you electronics wizards here can shed some light on this for me as it would be good to get it usable again. Please see photo's below of various bits. Many thanks, Simon. The Dremel charger appears to be designed to work with sveral different devices, but the one you have has a "10.8v" battery pack so you need to set your charger to 10.8v. My chargers do have a separate LiIo prog. and I always use it because it is a different voltage to Lipo, and yes I always balance charge any Lipo or LiIo, but I know some people don't. Dick Quote Link to comment Share on other sites More sharing options...
mightypeesh Posted May 29, 2015 Author Share Posted May 29, 2015 Hi. Yep the fuse is fine there. When it went it had that overheated electrical smell so I unplugged it and it has never worked again. If I need to set my charger to 10.8 then I am scuppered as the charger only goes up in multiples of cells in Li-ion (or lipo as it is on this charger)- ie 7.4, 11.2 etc. Might have to think again. Cheers, Simon Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted May 29, 2015 Share Posted May 29, 2015 Hi You may find that your batteries have protection board built in . if that's the case then a standard charger will be able to charge it with the protection board switching off the charge as a lipo charger does.Just make sure you have the correct polarity and voltage selected. Our lipo chargers will not work if a protection board is fitted as it cannot get any feed back from the cells . Does the Dremel just stop working when its flat or does it slowly die ? If it suddenly stops then it wil more than likely have a protection board fitted.Can you undo the battery case to check ? The bord is a small PCB fitted in the case and takes care of over discharging/charging and balancing cells . Quote Link to comment Share on other sites More sharing options...
Kevin Wilson Posted May 29, 2015 Share Posted May 29, 2015 Your charger show it has a Li-0n setting. which may be buried in the setup menu, changing the LiPo votages to LiOn alternatives. This should allow you to set a 3S 1.3A charge closer to 10.8v If it was me, I would be using my multi-meter to probe the battery to find the balance connections. I am a cool cucumber when it comes to lithium cells, but I always balance charge at 1C. I agree with ED, our hobby chargers do throw a wobbly if there is any protection circuitry in line. Quote Link to comment Share on other sites More sharing options...
Dickw Posted May 29, 2015 Share Posted May 29, 2015 Posted by mightypeesh on 29/05/2015 11:09:08: ...... If I need to set my charger to 10.8 then I am scuppered as the charger only goes up in multiples of cells in Li-ion (or lipo as it is on this charger)- ie 7.4, 11.2 etc............ Cheers, Simon I just looked up the manula for the Elysium LX60B Pro ( **LINK** ) and it says it can be set for Lithium-Ion charge as well as Lipo. Page 8 explains how to change between Lipo, LiFe and LiIo. 10.8 volts is just 3 cell LiIo as 11.1 v is 3 cell Lipo. Dick Edited By Dickw on 29/05/2015 12:32:08 Quote Link to comment Share on other sites More sharing options...
mightypeesh Posted May 29, 2015 Author Share Posted May 29, 2015 Ok, thanks for that - clear case of read the instructions. I did scroll through earlier, but becaus it said 'LiIo' on the screen my brain dismissed it - yep, I know - no excuses! Right. I have now set the charger ok. I have taken the pack apart and it has three cells and a resister as well as a wire that goes down the side of one and stops at a bit of metallic tape. I have put my multimeter across it all and I am looking at it with the three side tabs at the top and the positive and negative terminals at the bottom. The pack reads 9.8v across the terminals and yep the pack just 'dies' rather than running down. positive teminal is on the bottom left negative on the bottom right left hand top tab nothing is connected. center top tab reads 9.8v when read across positive terminal right top tab reads 9.8v when read across positive terminal Cheers chaps Simon Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted May 29, 2015 Share Posted May 29, 2015 Hello Simon your battery looks like it doesn't have a protection board so should charge ok on your Elisium charger set to 3s Li-ion You could always use the old Dremel charger case for a charging dock and run a lead out to plug into the Elisium . I would try test a charge while stripped down as in picks to see if it accepts charge ok.. Or you could rewire the battery as per this diagram with a seperate charge and balance lead and just plug it into your charger Quote Link to comment Share on other sites More sharing options...
mightypeesh Posted May 29, 2015 Author Share Posted May 29, 2015 Thanks, that is a great link saved straight into my useful stuff folder. I will try the first option before I go the balance lead way I was hoping to use the old dremel case as a charging dock but am still a bit confused as to what wire goes were? Ok. Positive and Negative obviously as normal - but what do I need to connect to the other two tabs. what are they for on the charger. as there are only two connected they are not for balancing are they? Sorry to be dense, Thanks, Simon Quote Link to comment Share on other sites More sharing options...
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