Turnigy 5.0

[silverbear]

Been trying to follow along to get a better understanding of the alternatives in batteries for ebikes... still a dummy however.

CB2, in an earlier thread you were using batteries from laptops for one of your builds. Are you now more sold on the RC batteries? Does one type have an advantage over the other? Can you compare them in cost, longevity, user friendliness or whatever you think is important?

You guys seem to have a good understanding of what you're doing, so chat away all you want. Thanks for sharing.
SB

 

[cannonball2]

SB, I have been using the R/C style batteries the longest(10+ yrs) and am most familiar with them. The 18650 lap top cells are similar chemistry(Li-Ion vs Lithium Polymer) but in a cell that is slightly bigger than a AA cell. The 18650 packs are assembled from individual cells and have a good bit of flexibility as to shape, voltage and AH and allow self assembly of course. The R/C batteries can simply be wired together using or modifying their existing wiring, but unless you disassemble the packs(not me!) you are locked in to using their brick like shapes. The Li-Ion don't have near the power density of the LiPoly cells, but are some what less volatile.
The R/Ctype batteries are probably more compact overall. Like I have mentioned you can easily hold 36v/5ah in one hand with this type.
Most of the negativity comes from folks that have little experience with them and or have handled them improperly.
If all the proper handling, charging, and discharging techniques are observed my experience has found them completely safe as I have not had any issues in the 10+ yrs. of using them. The R/C type is what will probably suit your hybrid builds the best.
This type battery is in reality no more dangerous than handling gasoline. We have just been brought up handling Gas so universally( most people anyway) know what and what not to do with it. Still I have seen more injuries to people in my life time from burns with Gasoline than any other energy source.

 

[silverbear]

Thank you for your detailed response! As discussed in other threads, the delta hybrid trike is planned to be 36V as that is what my controller is set up for in the old lead acid batteries. The Golden pancake motor is one of the early ones and is a front wheel. If I stay with 36 volts can I use my old controller or does the RC battery require something peculiar to it?

I understand that the RC battery requires it's own kind of charger. If the delta trike is set up for 36 volts and the tri-car for 24 volts (used mostly for starting the ICE) can I use the same charger to charge either bike in spite of the different voltages? If the charger is voltage specific then I might be better off going to 36 volts for both bikes so as to have just one good quality charger/discharger. However, then I am less likely to be able to fit 36 volts worth of RC batteries into the newly made copper tool box which is cylindrical in shape while the batteries are bricks.

I gather you are both using the same kind of battery (Turginy 5.0). If I were to use the same battery how many bricks to make 24 volts and how many to make 36?

Do these batteries have a pretty good life span? The price sure seems right. Thanks for answering elementary school questions. I don't want to pretend that I know more than I do and would rather ask too many questions so that I do things right the first time around.

Thank you both for your patience.
SB

 

[cannonball2]

You are most welcome SB! If you buy the standard R/C charger you can use it with both 24/36v by charging the cells individually(actually on a multiple charging board). Most common chargers will charge up to a 6S battery. Lipos are made from 3.7v pouches. They range from 3.7v(a single cell) on up. Im running 4S packs(3.7vx4=14.8v nominal) in series for a total of 29.6v in my 24v system. These come off the charger at 33.6v. the 24v system is perfectly happy with this voltage and actually makes more wattage. The only issue with using a controller for SLAs is the low voltage cut(LVC) is too low for the Lipos. The 24v SLA LVC is usually around 21v, that will kill the Lipos permanently. So you need to monitor a volt meter and cease discharge in range with the Lipos. In the 24v system on 4S its 28v. The recommended discharge voltage is ideally 3.5v/cell. So you just multiply 3.5x the number of cells to get the LVC.
I know this sound complicated but its not! Generally you keep series/ paralleling packs to get the voltage/AH desired. They make connectors so this is plug n play. You can buy the packs necessary for a 36v system then just use enough packs from it to run the 24v system(assuming you are never using both bikes at the same time).
You could run 3S packs(11.3v nominal) this would yield a 22.2v pack This is on the low side voltage wise(I like to over volt systems). It will come off the charger at 25.2v which decent enough voltage for operation, but better yet the 24v LVC will cut the system out at exactly the right voltage, 21v. The same applies for the 3S packs when built to 36v. The LVC is just right. Also 3S packs are the most common and therefore cheaper!
I know this is a long post. I have tried to make it clear, but probably didn't, so just ask all the questions you want.

 

[cannonball2]

Heres some pics to put it into perspective. I believe for starting only purposes 5ah would do your trikes. Im holding a 14.8v 5ah pack in my hand to show size. Two of these(or even smaller 3S) would make a starter pack. The pic of 4 could make a 59.2v 5ah pack! Look at the size! You just put em together to get what you want. At this point in time these are the best bang for the buck size wise and usually $$ to.

As far as longevity, if max charge/discharge voltages are observed and they kept at storage voltage when not in use, a good quality pack lasts longer than most chemistries.

 

[silverbear]

So besides the batteries and appropriate charger I would also need speed controllers for each bike, one for the 24V tri-car and one for the 36V delta hybrid. Looking at the Hobby King site there are a whole lot of speed controllers. How do you know what is the right thing?

A "cycle analyst" has been mentioned. Is this also something each build needs to have? Since both hubs will be of the direct drive type then there would be regenerative charging going on while under ICE power, so being able to monitor the state of the batteries at any time is imperative, is that right?

Is there anything else needed, aside from connectors and that sort of thing? It looks to me like there would be enough room in the copper tool box for three of the batteries making a 36V. system possible. That might make the tri-car more versatile for very little more money. Say for riding on a sanctioned bike trail under electric power where the gas engine would not be permitted. Something to consider before buying anything...

Thanks again for the great input. Eventually I'll get savvy with this stuff.

I can see that these RC batteries are my best bet. Size, money and simplicity (over building packs from lap top batteries) make them a good choice. I need to get familiar with the do's and don'ts of these batteries and treat them with care.
SB

 

[cannonball2]

SB, using the R/C controllers requires a good bit of expertise to convert. Stay with the controllers that you have/or will come with the kit intended for SLAs, they work fine excepting monitoring the LVC if over volted. Packs made with the 3S batteries should work basically like an SLA with these controllers(better performance of course).
A cycle analyst is a great item to have, it offers complete control of the system from one point. You can set the LVC where you want so as not to have to monitor an over volted situation. Its is however not very complementary to a vintage build if out in the open. Maybe you can "hide" it.

If you use the 5AH pack either 24/36v you have limited range, these were suggested for starting. For practical usage you would need to double the packs to get 10AH. If heavily loaded the 5AH pack will probably yield considerably less than 10mi. I have gotten right at 10mi here in the flats on my lightest bike.

I would make a motor disconnect of some sort to shut out regen so as not to over charge the Lipos (a big NO NO!) when underway with the ICE. If you can easily monitor the voltage fed back to the pack then you could disconnect when recharged.

The only thing you really need excepting the motors/controllers you may not have are the batteries and connectors to series/parallel the packs, and a charger and multi board. The Cycle Analyst would be a great thing if you can work in in. You at least need a digital voltmeter somewhere.

 

[silverbear]

Thanks again for responding. It sounds like I am best advised to keep to the original intent of using these batteries for starting purposes, especially with the 24 volt tri-car, Keep it minimal and simple.

Since I have a controller for 36V which came with the original pancake Golden Motor and which was for SLA batteries, I'll stay with that for the hybrid delta trike. As you say I can simply do an on/off disconnect to avoid over charging the RC batteries so long as I closely monitor charge level. I'm the one riding this, so it doesn't need to be automatic. If at a later time I want to revamp the ebike part of the build I can get a 48 volt controller and go to 10Amp in RC batteries for more serious ebiking. It might be smart even while 36V to double up the batteries to 10 amp. Enough room for either batteries or controller is not a concern with the delta trike... plenty of opportunity to hide things.

An asphalt bike trail is eventually being finished up which uses for the most part an old railroad grade connecting the two local towns I live between. Either direction would be about 12 miles to town and part of that would have to be in electric mode. The delta trike, perhaps with a kiddie trailer for cargo would make a nice ride through the forest to pick up groceries and such. Having flexibility between ICE and electric and being able to later beef up the electric is really nice. I can adapt the trike to fit my riding situation as it changes. Perfect!

The tri-car is something more for showing off a bit and going to bike shows maybe, that sort of thing, so having the minimal 24V electric hub mainly for starting the ICE engine is good enough.

Your explanations help me to think things through and make more effective plans. No sense buying what I don't need or going overboard on "more power". As with gas engines, bigger is not always better. Faster is not usually wise... fun maybe, but not wise.

You mention my needing a "multi-board". What is that? And what do you suggest in connectors?
SB

 

[cannonball2]

Heres a pic of an R/C charger and the charging plate. I run two chargers at the same time with up to 4 batteries per plate. Each plate will charge 6 batteries at once but that far exceeds my chargers amp out put. For using the 24v 5AH pack you would only need one charger to charge two batteries(same for 36v 5AH). You could do them individually, but its faster to do them at the same time using the plate. For 10AH I recommend two chargers. Its faster and easier on the chargers. If you upgrade to a high output charger then one charger can charge all batteries at once. These are entry level chargers(around $40) and one has been with me for years. You can if money is no object buy some fine multi-featured chargers.

Cool thing about R/C chargers is many are dual voltage-12/120v. Means you can carry the charging stuff on the bike and charge off a car battery if you have one around, in the absence of 120v.

Look further back in this thread and you will see the parallel/series connectors. Lungcookie directly connected his pack with Anderson Power Poles.
Another good way to make a modular pack. I left mine as they came to do double duty in my R/C stuff, and just connect the packs as necessary for E bike usage.

 

[Lungcookie]

SB
You really don't need a CA, but they are super cool, if a bit expensive.
Lets you see whats up with your batteries on the fly among other things.

Check it out.


http://www.ebikes.ca/product-info/grin-products/cycle-analyst.html


Looks like CB2 is the man with the plan, your in good hands.

With that charger multi-adapter and the way I am charging its looking at a 30,000ah battery. And it takes quite a while to charge, almost 5 hours from 3.8v/storage voltage. That is the biggest drawback to using this set up.

 

[cannonball2]

Yikes 30,000AH!!! Better get a direct line from the power company-lol.

Get another charger and plate, blow the fan over both and cut your time in half.

BTW not trying to choke your thread just seemed like a good place to explain the nefarious world of the Lipo battery to SB. And maybe a few other folks that are convinced they will spontaneously combust at any given time.

 

[Lungcookie]

CB2
I all ways welcome your advice and knowledge. Keep it coming.

I mostly started this thread because you/CB2 and deacon were playing with batteries and I was in the market for a new battery. However you were already one step ahead of me.


I have what amount to 5 chargers so I can cut the time down.
Just wanted to try and put the multi-charge adapter method into perspective.

 

[cannonball2]

CB2
I all ways welcome your advice and knowledge. Keep it coming.

I mostly started this thread because you/CB2 and deacon were playing with batteries and I was in the market for a new battery. However you were already one step ahead of me.


I have what amount to 5 chargers so I can cut the time down.
Just wanted to try and put the multi-charge adapter method into perspective.

Gotcha LC. I have found that using the plates is somewhat faster than individual charging. Using multiple chargers is even faster of course.
I used to spend all morning running 3 chargers charging all the packs for my planes and helis to fly in the afternoon. Bummer was any I didn't get around to flying I would spend all evening discharging!
When I first started with Lipos no one knew(or told us) that not discharging to rest voltage would drastically reduce pack life. First packs didn't last very long.

BTW I don't think I was ahead on this seems like both our orders were in transit at the same time. Great minds you know!

 

[silverbear]

The last couple of posts raise the question in my mind about partial discharge, partial charge and regenerative charging. At what state of charge are the RC batteries most happy? Is it best to not fully charge them?
SB

 

[cannonball2]

Generally the full charge is 4.2v cell and the ideal max discharge is 3.5v/cell. For storage(more than just a few days) they are left at 3.85v per cell. The R/C type chargers have a program that will charge/ discharge your pack to the proper voltage.

Practice is to fully charge Lipos. Li-Ion are often charged to 4.15v to extend the life.

Real world: charge your Lipos fully-4.2v, don't discharge below 3.5v and leave em sitting at 3.85. Observe these values and you will get max cycles.

 

[Lungcookie]

That is perfect world conditions and best battery life.

My SKYcharger charges to 4.2v/cell, discharges to 3.0v/cell and stores at 3.8v/cell.
Factory set cant adjust.

Seems like I have read over at endless-sphere 3.65v to 4.17v range, for long life. Under 2.7v/cell and you will kill them fast.

My 4x charger seems to do what ever it feels like at the time, sometimes works good, sometimes just cant seem to get the voltage right, sets off alarms all the time.
Starting to think its total junk.

If you read the fine print on the LiFePo4 and getting 2000 cycles out of it.
You will find that they also have certain charge/discharge limitations to make them last.

One thing with these LiPo's I like is that you can see what's going on with the batteries at the cell level and you can replace a pack without battery surgery like with pre-made batteries.

You spend 300-500 bones or more on a battery, one bad cell dies, it starts to kill the whole pack after awhile. Are you going to rip it open and track down the bad cell/cells? Or did you just eat it?

With these R/C chargers you can tell what going on as it is happening, that is of course if the charger is any good.
26 bucks gets you going again if a pack dies.

I just started playing with the LiPo so I will see what happens.
Looks like some happy customers at endless-sphere.
I had small 1-2 cell packs for mini heli's they did not last 9 months, but I didn't know the happy cell range at the time.

 

[cannonball2]

Im rethinking the battery situation. I have been with lipos so long why change? I like my Li-Ion batteries fine, but your are right, anything goes wrong you got to bust em open. Plus I don't like the idea of a BMS. The way we are using lipos is just about ideal. As long as we don't low volt em the rest is handled by the charger. They get balanced every charge just like a BMS except theres not one. Cool!

The modular add/subtract aspect is cool too.
Im thinking of a 72v system now. Time to go to HK for some shopping!

 

[cannonball2]

Put 4 of these together and I got it going on! I like the long shape too, looks like its made for down tube mounting. Have to by a proper charger though. http://hobbyking.com/hobbyking/store/__21368__ZIPPY_Compact_4000mAh_10S_25C_Long_Lipo_Pack.html

 

[silverbear]

I'm trying to get up to speed on all this e bike stuff which can be confusing. I just did some looking on Endless Sphere for a "tutorial for dummies" and found a nice resource...

http://www.endless-sphere.com/w/index.php/Main_Page

...which should take you to the Endless Sphere Wiki. From there you can read up on terminology, concepts and specific information handy to ebikes. Something tells me I'll be spending some time there. Take a thermos of coffee and a bag lunch along maybe.

Question: while I'm still in the planning/figuring stuff out stage I was wondering about the advisability of going to 36v. with 5 amp RC batteries instead of 24v. I think my copper tool box would hold 3 of the battery packs. The tri-car rear wheel direct drive hub is intended to be primarily a way to get the tri-car rolling up to speed for letting out the clutch on the ICE engine, but with the possibility of a passenger up front the total weight of the tri-car would be on the heavy side. Would 36v. be better than 24V.? If I understand correctly increasing the voltage primarily benefits top end speed, which would not be a great benefit with my situation. So maybe 24 is just as good for me. What do you think?
SB

 

[cannonball2]

If you 36v a 24v system both torque(wattage) and speed are increased and amperage draw goes down a bit. If you are starting out with a 36v system then get at least a 500w motor. My 500W cargo bike pulls from stop fully loaded on 36v SLAs(36lbs of batteries!) with no issues and if you are easy with it fairly low amp draw.
Higher voltage is always better to the point where you over volt the system(not a concern for you)
Since your ICE is clutched why not start with out the passenger then just pick them up?
Im guessing that the trike with riders could top 600+lbs? That's a pretty good load.

Short answer is go with the highest voltage you can stuff into the "can". Your common 500w 36/48v controller is limited to around a 15amp draw so even lower end Lipos should survive nicely. You planning on 3S packs?