gwhy Posted August 7, 2015 Report Share Posted August 7, 2015 yes pos to neg is series... the problem with these sort of setups is the charging procedure, as there is no balance charger for 12 cells so each of the 3 batterys will have to be charged individually or you have to make a charging harness so the 3 batterys can be put in parellel to charge as 1x 4s3p battery... thats why it may be best to buy a 12s lifepo4 bms and use the standard 36v charger. Quote Link to comment Share on other sites More sharing options...
ali210984 Posted August 8, 2015 Report Share Posted August 8, 2015 It's OK I don't mind charging them individually as she only gets to ride it 1 or 2 times a week. What connectors do I use or are the bullet points ok to use which are already on there? And could you send me a link to the charger I will need please so I don't buy anything wrong. I knew this site was a good idea lol thank you for all your help Quote Link to comment Share on other sites More sharing options...
mikedufty Posted August 8, 2015 Report Share Posted August 8, 2015 (edited) These are neat for doing series connections. http://www.hobbyking.com/hobbyking/store/__10264__XT60_Harness_for_2_Packs_in_Series_1pc_.html or these for parallel http://www.hobbyking.com/hobbyking/store/__23132__XT60_Harness_for_2_Packs_in_Parallel_1pc_.html But will only work if you first convert the battery connectors to XT60 They have an XT to 4mm bullet converter for the LiPo batteries, but for the 5.5mm on the LiFePO4 you would probably need to solder some of these on http://www.hobbyking.com/hobbyking/store/__9572__Nylon_XT60_Connectors_Male_Female_5_pairs_GENUINE.html A bit of a pain, but nice to have connectors that are hard to accidentally short or get reversed, and most of the chargers have an xt60 output. I thought one of the best parts of the LiPo conversion was being able to use the hobbyking chargers which have a screen that tells you exactly what they are doing and have done (voltages, Ah in etc.) they have a huge range. I've bought this accucell 6 which has been good. http://www.hobbyking.com/hobbyking/store/__7028__Turnigy_Accucel_6_50W_6A_Balancer_Charger_w_Accessories.html Also this hobbyking branded one, which has a noisy fan but otherwise works OK And just recently this X120 which has a really nice colour touchscreen interface that shows all the stats at once, but seems to charge one cell 0.1V more than the others which may be a problem. http://www.hobbyking.com/hobbyking/store/__74035__X120_120W_Touch_Screen_Smart_6S_Balance_Charger_AU_Warehouse_.html If you disconnect the batteries for charging you can run them in series and charge them in parallel. Use a parallel balancing lead pack to do balance charging in parallel http://www.hobbyking.com/hobbyking/store/__27075__JST_XH_Parallel_Balance_Lead_6S_250mm_6xJST_XH_.html Actually if you are getting the 12v lipos you probably need the 3s leads http://www.hobbyking.com/hobbyking/store/__32031__JST_XH_Parallel_Balance_Lead_3S_250mm_6xJST_XH_.html?strSearch=balance%20lead%203s I forgot to mention the chargers above all need a 12v power supply. If you don't have one hobbyking sell them, but I've had no problem finding old laptop chargers for free that work great. Edited August 8, 2015 by mikedufty Quote Link to comment Share on other sites More sharing options...
redline2097 Posted August 8, 2015 Report Share Posted August 8, 2015 Our son just turned 2,5 years this week and we tried first time on track without training wheels. Going fast allready At the times we are running on local forest so i added wireless Relay up to 500 meters. I can now switch the bike off if my son runaway from me. That happened two times before I added the relay. Pretty heaty situation Quote Link to comment Share on other sites More sharing options...
ali210984 Posted August 10, 2015 Report Share Posted August 10, 2015 Hi thanks Mikedufty any chance you or anyone could write me a shopping list for running the 3 lifepo batteries in series exactly what I need with link if you don't mind and would be very kind thank you Quote Link to comment Share on other sites More sharing options...
ali210984 Posted August 10, 2015 Report Share Posted August 10, 2015 Or Mikedufty a list for the lipo if you only changed the connectors for battery's on the oset and batteries to the xt60 connectors. Is it the same charger for the Lipo and lifepo4 batteries? Quote Link to comment Share on other sites More sharing options...
mikedufty Posted August 11, 2015 Report Share Posted August 11, 2015 The hobbyking chargers can all be used for either battery type (you need to select the battery type when you use it). I think I listed most of the parts above. I've been running a 24v(6S) plus a 12V(3S) lipo in series, but mainly because I had it all running on 24V first so already had the 6S. If you were building it as 36v from scratch it would probably be better to run 3x12v (3S) batteries because you could charge them all at once in parallel. I have to charge the 6s then the 3s which is a bit of a nuisance. Quote Link to comment Share on other sites More sharing options...
bowser Posted August 11, 2015 Report Share Posted August 11, 2015 i would still go down the route of using lifepo4 , they can be bought from Hobby king and look very simular to lipo but they do cost a little more. You still will have to wire them up but they are a little more forgiving than lipo, they have very simular performance/size and weight to lipo. you will need 3 of these for a 36v battery http://www.hobbyking.co.uk/hobbyking/store/uh_viewItem.asp?idProduct=32206 plus a charger and all the adaptors and connecting leads .. If you are in the uk .. if you do get batterys from hobbyking make sure you get them from the uk warehouse of you will get stung on postage and import duty. hi, i'm guessing 3 of these would suit my oset 16 36V or is there something better? to add BMS so i can just use the standard 43v charger, what parts do I need? the Earthx are going to cost over $900 delivered so looking to spend half that or so. I want something that gives good battery life and isn't too hard/PITA to charge up when required. if you had $500-600 to spend on batteries, charger and connectors, what HK parts would you order? Quote Link to comment Share on other sites More sharing options...
gwhy Posted August 11, 2015 Report Share Posted August 11, 2015 (edited) yes 3 of those will suit the 36v 16.. or if you want more capacity then get a total of 6 batterys to make up a 16ah 36v battery make sure 6 batterys will physically fit in the bike ( along with the bms ) to use a standard 36v charger you will need a 12cell bms http://www.ebay.co.uk/itm/36V-60A-LiFePo4-Battery-BMS-LFP-PCM-SMT-System-12S-12x-3-2V-eBike-Battery-12x-3V-/321048908605?hash=item4ac001933d you can shop around for a bms but make sure you get at least a 60A 12cell lifepo4 bms, a 100A will give a little more over headmaybe even go for the higest you can afford , that seller also does a 150A bms you will need to solder the battery together, fit charge/discharge leads and plugs and also fit the balance port plug onto the battery pack once assembled so you will need access to a soldering iron. if you do the 16ah route this will be equivalent to 6x earthx batterys so there is massive saving to be had. once assembled then you treat it just as the sla's as regards charging. edit: also buy 1 meter of red and black 10awg wire http://www.hobbyking.co.uk/hobbyking/store/__78181__Turnigy_High_Quality_10AWG_Silicone_Wire_1m_Black_.html http://www.hobbyking.co.uk/hobbyking/store/__78180__Turnigy_High_Quality_10AWG_Silicone_Wire_1m_Red_.html and i would use xt90 connectors for the main discharge plugs ( 1 to fit on the battery and 1 to fit on the bike ) http://www.hobbyking.co.uk/hobbyking/store/__24707__Nylon_XT90_Connectors_Male_Female_5_pairs_.html also get some heatshrink to cover all bear soldered joints on the plugs.. you will also have to buy a matching charge port socket ( for the battery ) to match you charger plug Edited August 11, 2015 by gwhy Quote Link to comment Share on other sites More sharing options...
ali210984 Posted August 11, 2015 Report Share Posted August 11, 2015 Ok I now understand the charger I need and the connectors xt60 I need to swap and run in series. If I go lipo with 3 x 12v3s can I get any make batteries? Which are the best make? Also can I run 3x12v6s? Quote Link to comment Share on other sites More sharing options...
mikedufty Posted August 12, 2015 Report Share Posted August 12, 2015 The S is the number of cells in series within the pack, so a 12v pack is always 3S and 6S packs are always 24v. I've only bought the zippy packs, because they are very cheap and seem well liked. The biggest 3S hobbyking have is 8000mAh http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=40081 This would probably give similar range to the standard lead acid, but much lighter. If you wanted more capacity you could get another set of 3 and either run it in parallel, or have it ready to swap over when needed. I've combined the approaches, use one set for running around the paddock, put both in for a trail ride. If going with 2 sets of 3 you could consider the hard case packs http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=40081 Only 5000mAh, but comes with a hard plastic case instead of shrinkwrap, so needs less protection. Hobbyking sell little fire resistant bags about the size of the batteries, which also makes an easy option for toughening them up a bit. http://www.hobbyking.com/hobbyking/store/__1114__85__Batteries_Accessories-Lipo_Safe_Bags.html Quote Link to comment Share on other sites More sharing options...
bowser Posted August 12, 2015 Report Share Posted August 12, 2015 Mike you have me confused with the S, the ones why listed are 4S yet suitable for my 36V application. I think for ease I will just get 3 of these batteries for a start (may add another 3 later on) and not bother with the BMS http://www.hobbyking.co.uk/hobbyking/store/__14074__ZIPPY_Flightmax_8400mAh_4S2P_30C_LiFePo4_Pack.html%C2%A0 and get a new charger specific to these batteries, any suggestions on a decent charger as there seems to be lots of the HK site thanks guys Quote Link to comment Share on other sites More sharing options...
ali210984 Posted August 12, 2015 Report Share Posted August 12, 2015 Hey bowser I'm with you on this there the batteries I'm going to go for 3 of them and run then in series. Quote Link to comment Share on other sites More sharing options...
gwhy Posted August 12, 2015 Report Share Posted August 12, 2015 the number of cells that make up a specific voltage depends on the chemistry of the cells lipo cell voltage is 3.7, li-on is 3.6/3.7 and lifepo4 is 3.2 and they so for 36v lifepo4 then you will need 12cell i.e 12s and because the voltage per cell is higher with lipo/li-on you dont need to many cells i.e 9/10s there is not a charger that can balance charge all 12cells at the same time so you would need to split the 3 batterys every time you recharge , which is fine as long as every thing is going well with the condition of the batterys... when you get to splitting batterys to recharge then you really need to be on the ball as to know what you are doing and the reasons why you are doing it. I have always recommended having a charger for each battery if you are splitting the battery down to recharge.. its a much safer option Quote Link to comment Share on other sites More sharing options...
bowser Posted August 13, 2015 Report Share Posted August 13, 2015 when you get to splitting batterys to recharge then you really need to be on the ball as to know what you are doing and the reasons why you are doing it. thanks for the replies guys, can you expand on this a little more? how long would a charge for one of these batteries take? what minimum voyage should I let the system get down too in use (i.e.: 30V) and is there a buzzer of something I could use for this warning? cheers Quote Link to comment Share on other sites More sharing options...
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