sunny Posted November 10, 2014 Share Posted November 10, 2014 Ok so I just came across this forum and decided it was worth joining! My first post concerns the feared GR16. When I received it, it would never charge fully, had very little power and maybe 12km range. This was strange as people always refer to this model as being the strongest out there with a decent range. The Chinese reseller kept making promises over weeks of replacing the battery (turns out there were defective cells). He never made good on these promises. But, wanting to ride, I came up with a solution that I want to share: A hot swappable battery mod. Essentially I made two 14 cell Lipo battery packs with 5800mAh. Each one gives me a range of 20-30 km depending on terrain (I like off road). The batteries attach to the compartment via Velcro and can thus be swapped quickly. It is not pretty as I chose large packs and they stand out slightly width wise. But, for those of you wanting to get more range, the mod is simple and works great. A simple 14s battery which you can buy for little money from your local hobby store or online (which is what I did) and away you go! Also: the battery cells hold their voltage better under stress. This means the motor power doesn't dip as much when you suddenly encounter steep inclines or obstacles. Link to comment Share on other sites More sharing options...
GQS Posted November 11, 2014 Share Posted November 11, 2014 That's great. Are you using the charging system in the Unicycle to charge the larger packs, or do you have an external charger? Do you have any pictures? Your mod sounds pretty nice. Link to comment Share on other sites More sharing options...
sunny Posted November 11, 2014 Author Share Posted November 11, 2014 You could theoretically use the original charging equipment as the voltage of the 14 cell Lipo battery is the same as the 28 cell which is originally in there. The thing is, that you have to connect your balancer cables from the new battery to the balancing board in the Rockwell, which I decided against. For this reason, I charge my batteries externally with a 500W charger. It is not as convenient of course as you can only charge at home and not on the go. But then again, I can have numerous battery packs in my rucksack if I want. I can't seem to upload pictures due to the file size limit. Link to comment Share on other sites More sharing options...
poiuz Posted November 11, 2014 Share Posted November 11, 2014 Compress the file^^ when you save the photo on photoshop for instance use "save for web" instead of "save" Link to comment Share on other sites More sharing options...
John Eucist Posted November 11, 2014 Share Posted November 11, 2014 I think size limit here is 1 MB. Can you throw it on imgur.com then imbed instead? Link to comment Share on other sites More sharing options...
sunny Posted November 13, 2014 Author Share Posted November 13, 2014 Link to comment Share on other sites More sharing options...
Kevin Lee Posted November 17, 2014 Share Posted November 17, 2014 Interesting mod indeed. Can't you take apart the battery covering and modify the cell configuration so that it can neatly fit into the compartment? Also, you can you buy a 16 pin socket and adapter and install it into your wheel. Actually, I have plans to mod my Gotway just like yours, with Li-Po or LiFePo4 cells. The balanced charging make much more sense, especially when there are so many cells in one battery. If one cell fails, they whole thing fails. I may even custom print a battery socket and install it on the wheel so I can quickly swap batteries on long rides. I'm still debating weather to add a battery extender to place on top of the wheel or use a replacement socket. You can search google for "16 pin plug and socket" and you'll see plenty of choices. I would like to add one thing to your mod though. LiPo can be very dangerous when even slightly damaged. They should be completely covered in a hard shell compartment. One little bump or puncture and the thing will become unstable and can explode. Please be very careful with it when exposed like yours. You can check YouTube for explosion samples on RC stuff. It's no joke even on a 4 cell battery. You have a dual 14 cell there so be extra careful. Link to comment Share on other sites More sharing options...
sunny Posted November 20, 2014 Author Share Posted November 20, 2014 Hi there. I know about exploding cells - I used to fly RC helicopters with 12 Cells. Yes, they are volatile. My Rockwheel battery has been "ejected" from the case a couple of times during crashes but luckily up to now always landed safely. A small dent is all it has. I always check it to see if it starts getting warm after these crashes and during subsequent charging. So far so good. A more ideal solution would be to have a hardcase for it, so that, like you correctly suggested, it is completely protected. To your other question - yes I could divide the cells up to better fit inside the shell, but have up to now not found a way where that would still allow me to have multiple battery packs that could be changed quickly. Link to comment Share on other sites More sharing options...
Sunny Rockwheel Posted April 2, 2015 Share Posted April 2, 2015 Hi there. I know about exploding cells - I used to fly RC helicopters with 12 Cells. Yes, they are volatile. My Rockwheel battery has been "ejected" from the case a couple of times during crashes but luckily up to now always landed safely. A small dent is all it has. I always check it to see if it starts getting warm after these crashes and during subsequent charging. So far so good. A more ideal solution would be to have a hardcase for it, so that, like you correctly suggested, it is completely protected. To your other question - yes I could divide the cells up to better fit inside the shell, but have up to now not found a way where that would still allow me to have multiple battery packs that could be changed quickly. oh same name~~~ Link to comment Share on other sites More sharing options...
Chimp Smith Posted April 9, 2015 Share Posted April 9, 2015 hello, wish u could made a video for this. Im having trouble with my 12'' rock wheel. It won't power on after a full charge. I even email the seller but no reply. Now with the weather starting to look good wish i could ride my rw. thanks Link to comment Share on other sites More sharing options...
EUC Extreme Posted April 9, 2015 Share Posted April 9, 2015 I also thought put into one of my unicycle Lipo batteries. I already have a charging equipment which I could 16S fully charge the batteries about 15 to 20 minutes. Then the aggregate of the car, and go offroad. I can run all day, if you just take a physics I have a RC helicopters also. And so it is ready for heavy duty charging equipment. I'll upload a helicopter 12S 3700mAh batteries for approximately 5 minutes. After 5-10 min. flight. And while charging for 5 min. This system works perfectly. So, I do not think that the unicycle in use should be no problems. In a much longer decay time. Link to comment Share on other sites More sharing options...
Chimp Smith Posted April 9, 2015 Share Posted April 9, 2015 I also thought put into one of my unicycle Lipo batteries. I already have a charging equipment which I could 16S fully charge the batteries about 15 to 20 minutes. Then the aggregate of the car, and go offroad. I can run all day, if you just take a physics I have a RC helicopters also. And so it is ready for heavy duty charging equipment. I'll upload a helicopter 12S 3700mAh batteries for approximately 5 minutes. After 5-10 min. flight. And while charging for 5 min. This system works perfectly. So, I do not think that the unicycle in use should be no problems. In a much longer decay time. u lost me haha Link to comment Share on other sites More sharing options...
EUC Extreme Posted April 9, 2015 Share Posted April 9, 2015 I took one download video. Link to comment Share on other sites More sharing options...
sunny Posted April 9, 2015 Author Share Posted April 9, 2015 Well, I've been out again today, did a long trip, around 40 km. The interesting thing - which you should be careful of if you build your own battery, is that the battery level indicator on the rock wheel is not set up for the lipos. The original battery has the same voltage per cell, but I think it can be discharged further than the lipo batteries. Today I rode around 30 km on one battery (5800mAh) and still had two red bars. I came home, attached it to my charger - turns out the battery had only 8% capacity left (each cell at 3.6v, should never be below 3.7). As a rule of thumb people say never discharge lipos below 20%. As I charged it again right away I doubt there was much damage - but just as a warning - when that last yellow light goes, switch to your next battery pack! Link to comment Share on other sites More sharing options...
EUC Extreme Posted April 9, 2015 Share Posted April 9, 2015 Of course I always have to put the alarm voltage which can be adjusted to the desired voltage. Can also put the one that measures the amount of energy consumed. Making it possible to extract exactly 80% of the battery capacity. I am also thinking about the external battery which is perhaps a backpack. Cable from there. Plug one that comes off, for example, to roll over. Easy to implement and the battery can be very high. Especially if it is a Lipo, which is also the light. Link to comment Share on other sites More sharing options...
hobby16 Posted April 10, 2015 Share Posted April 10, 2015 Well, I've been out again today, did a long trip, around 40 km. The interesting thing - which you should be careful of if you build your own battery, is that the battery level indicator on the rock wheel is not set up for the lipos. The original battery has the same voltage per cell, but I think it can be discharged further than the lipo batteries. Today I rode around 30 km on one battery (5800mAh) and still had two red bars. I came home, attached it to my charger - turns out the battery had only 8% capacity left (each cell at 3.6v, should never be below 3.7). As a rule of thumb people say never discharge lipos below 20%. As I charged it again right away I doubt there was much damage - but just as a warning - when that last yellow light goes, switch to your next battery pack! RW has Li-Ion cells with 0,1V/cell lower voltages than your LiPo (3.6V nominal instead of 3.7V, 4.1V max instead of 4.2V), so indeed, the wheel's indicator may be inaccurate. However, your low threshold are very very conservative, LiPo can be discharged down to 3.5V and 5% without damage (highest stress occurs with the top charge, above 90%) and on Lipos, the voltage decrease is very steep after 3.6V, so maybe your the wheel indicator is usable after all. If you do want peace of mind, use a $2 Lipo checker with modifiable low threshold and buzzer alarm (it's very loud, you won't miss it). Your lipos don't have hard cases, so you should pay as much attention to low voltage thresholds as to shock protection (especially at the bottom of them, since your pictures seem not to show any). It's funny Rockwheels have 14S batteries, it must be because of the geared motor. Most direct-drive wheels have 16S batteries. Link to comment Share on other sites More sharing options...
sunny Posted April 11, 2015 Author Share Posted April 11, 2015 yeah, I don't use any shock protection and they have been "ejected" a few times - but generally only at very low speeds. I check they aren't damaged so they won't catch fire. IF they do well then that's tough luck for me ;-) Link to comment Share on other sites More sharing options...
EUC Extreme Posted April 11, 2015 Share Posted April 11, 2015 Lipo battery lasts almost put the node While it without the danger of fire. But if there's even a small hole in the aluminum bag. It's usually fire. But I have seen a number of lipo batteries with even a large hole, but still would not have broken out. Link to comment Share on other sites More sharing options...
CloudMG Posted May 12, 2015 Share Posted May 12, 2015 this is what i wanna do, place a scooter battery in one,any one tried placing a scooter battery in one?there cheap and that might give a cool boost, what i whant is at least 30km range Link to comment Share on other sites More sharing options...
CloudMG Posted May 12, 2015 Share Posted May 12, 2015 or how about one of these that can jumpstart a carhttp://www.passiongadgets.com/13800mah-car-starter-portable-powerbank-for-laptop-samsung-iphone-usb.html this one maby=? http://www.dx.com/es/p/wild-scorpion-replacement-14-8v-60c-5500mah-lithium-battery-pack-for-r-c-helicopter-184639#.VVJNGpNQ2KF Link to comment Share on other sites More sharing options...
CloudMG Posted May 12, 2015 Share Posted May 12, 2015 http://www.dx.com/es/p/singfire-sf-b12-13200mah-8-4v-12-x-18650-li-ion-battery-pack-for-1200-5000lm-cree-led-bike-headlamp-271287#.VVJJ7ZNQ2KF This looks great and has great price Link to comment Share on other sites More sharing options...
CloudMG Posted May 12, 2015 Share Posted May 12, 2015 an this one has a power on off swich http://www.dx.com/es/p/1298a-12-6v-9800mah-rechargeable-li-ion-battery-w-us-plug-power-adapter-227814#.VVJJ95NQ2KF Link to comment Share on other sites More sharing options...
sunny Posted May 12, 2015 Author Share Posted May 12, 2015 Look at your charger. The one that came with your wheel. On the back is a sign with a voltage. Your replacement battery needs to have exactly that voltage. You are showing me 12 volt batteries. You can buy those to power your headlights or other gadgets you might add to your wheel, but not the motor Link to comment Share on other sites More sharing options...
sunny Posted May 12, 2015 Author Share Posted May 12, 2015 You can buy Lipo batteries (you have li ion in your links) from hobby stores online. I for example am running 14 cells which equates to the same voltage the original li ion had. Link to comment Share on other sites More sharing options...
CloudMG Posted May 12, 2015 Share Posted May 12, 2015 oks , well i havent got any unicyle yet ^^ there on the way and its for buissnes, but the unknown cheap brand that i boght defenetly have bad batterys so i need a cheap way to fix this, if i offer a unicycle that runs for 5km i aint gona sell squat ) Link to comment Share on other sites More sharing options...
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