coolchinateacher
100 mW
Here is a picture of the pack I have.
About the same size and weight as a ping but better cells.
About the same size and weight as a ping but better cells.
-
Howdy! we're looking for donations to finish custom knowledgebase software for this forum. Please see our Funding drive thread
Best Bet with Lifepo4
- Thread starter kalpatarutree
- Start date
dogman dan
1 PW
Nice looking to me Cool, Are those round a123's inside? And what AH is that in the pic, and what is your price before shipping? If I wasn't perpetually broke, I'd love to buy one of those!
Assembling the pack is a turn off for many, as well as the price of A123's. But they are cheaper than they used to be so worth it if you do have the money. We buy the large size in the pings because we have to due to the low c rate. If you don't need 20+ miles of range, a smaller A123 pack would be great, weigh less, and be easier to mount. All the advantages of lipo with the less worry charging of lifepo4. Perfect. With the avaliablity of A123 cells now, it's going to be nice to just buy an assembled A123 pack in the future. No more having to buy tool batteries and extract cells from them.
I'm not a shill for Ping, but I do hate to see people who do need all 20 ah go and save a hundred dollars buying a pack with a reputation for delivering 20% less than advertised when used at 15 amp discharge rates. I bought one of the early V1 ping packs, and it's still going fine for me 6000 miles and almost 3 years later. It's seen plenty of abuse, bike crashes, etc. But always discharged at 1c or less. (20 amps) I still feel that for a guy who just wants an easy to charge pack for longish range a Pingbattery is a choice that makes sense. If it does last you 3 years, then you get a low cost per mile in the end. You have to use a low discharge rate though, so no x5 motors with 40 amp controllers on the pings. Perfect though, for riding to work at 20 mph.
Re the thunderskies, reasonably priced lifepo4 chargers are avaliable various places for 36v, 48v, etc. So if you bought the thunderskies you could likely get the charger from the same vendor, in the voltage you need. If you ran with no bms, then some kind of low voltage warning device would be good, and then you'd want to perhaps charge with 12v chargers occasionally if one block got too out of balance with the others.
Assembling the pack is a turn off for many, as well as the price of A123's. But they are cheaper than they used to be so worth it if you do have the money. We buy the large size in the pings because we have to due to the low c rate. If you don't need 20+ miles of range, a smaller A123 pack would be great, weigh less, and be easier to mount. All the advantages of lipo with the less worry charging of lifepo4. Perfect. With the avaliablity of A123 cells now, it's going to be nice to just buy an assembled A123 pack in the future. No more having to buy tool batteries and extract cells from them.
I'm not a shill for Ping, but I do hate to see people who do need all 20 ah go and save a hundred dollars buying a pack with a reputation for delivering 20% less than advertised when used at 15 amp discharge rates. I bought one of the early V1 ping packs, and it's still going fine for me 6000 miles and almost 3 years later. It's seen plenty of abuse, bike crashes, etc. But always discharged at 1c or less. (20 amps) I still feel that for a guy who just wants an easy to charge pack for longish range a Pingbattery is a choice that makes sense. If it does last you 3 years, then you get a low cost per mile in the end. You have to use a low discharge rate though, so no x5 motors with 40 amp controllers on the pings. Perfect though, for riding to work at 20 mph.
Re the thunderskies, reasonably priced lifepo4 chargers are avaliable various places for 36v, 48v, etc. So if you bought the thunderskies you could likely get the charger from the same vendor, in the voltage you need. If you ran with no bms, then some kind of low voltage warning device would be good, and then you'd want to perhaps charge with 12v chargers occasionally if one block got too out of balance with the others.
coolchinateacher
100 mW
dogman said:
A123 18650 cells
16s 20ah. 340x140x140mm, weighs about 12k
I'm an American ex-pat teaching in China. I did a ton of searching to find this supplier and their prices are fantastic. The only issue is they will only accept payment in RMB which can be a pain in the rear. They refuse to use paypal becuase the fees here to transfer funds from it to RMB are outrageous. Living here I have found a way around it because I needed to. My mission here keeps me pretty busy but I may be willing to help members here by acting as a middleman. PM me if ya want more info.
Eric
999zip999
100 TW
Sounds great what is the support system for cells and bms ect. ?
dumbass
100 kW
kalpatarutree said:
You are almost correct. Please understand that a good BMS actually should be monitoring a packs change and discharge. By buying your 12v TS packs with the balancers this should eliminate the charging issue. However, it does nothing for the discharging which can be a little tricky. I do not use a LVC (low voltage cutoff).at this time. However, this is a personal thing and is not something I recommend.......it's just what I do. I am telling you this because I do not want you to think you are 100% protected if not using some type of LVC. If your pack stays in balance during discharge then you will never need a LVC. However, if for example you decide to do an extra long ride or climb a lot of hills requiring higher then normal loads one cell could fall below the others. The pack could be well within normal voltage so you won't know you have a single cell's voltage falling below a safe level.
It you fine the TS cell meet your requirements then I would buy them and be sure to break them in properly. When you have a little more cash you can add a LVC or CellLog8 monitors. I use CellLog8s because they have a small screen so I can see what has been going on.
As for charging you can charge with an SLA charger........however, an SLA charger will likely not charge the cells to a full 3.65v. When I use a 12v SLA charger the cells normally average out at about 3.5. Some are going to tell you this is undercharging the cell and you will loose cell capasity. I say BS! The losse is maybe 1/2 mile in lost capasity because anything over 3.6 burns off very quickly. In fact if you leave the pack sit over night it will drop to around 3.6 anyway. So what does that tell ya? YOu may have a hard time finding a 48v SLA charger. And if you have to buy one anyway...well why not buy one designed for lifepo4? While I carry twin 24v packs all my bikes are 24v. And I had several 24v and 12v SLA chargers. This is the main reason I still use SLA chargers. But I also built 2 24v lifepo4 chargers using single cell lifepo4 chargers. So I can bulk charge and single cell charge at the same time if I am in a rush. To keep things simple for you I would recommend buying a 48v lifepo4 charger. This will take out a few what ifs for you.
I hope this answered your questions and didn't add more confusion for you.
Bob
dumbass
100 kW
coolchinateacher said:
dumbass
100 kW
coolchinateacher said:
No offence but there is something nice about using PayPal or ever credit card comps like American Express. I have had a few problems with suppliers and the only way I got what was promissed was by stopping the payment. You stop the payment and you get what you want. I've also found that companies that don't want to except PP and or some CCs are not quality companies I wanted to deal with anyway.
Bob
999zip999
100 TW
Hay Kapla, What amp. and kind of controller do you have important ?
The Mighty Volt
1 MW
This is what you need: Get loose A123 and solder them up. Then throw your frame on the ground, and start planning about how you are going to arrange them.
cell_man offers these A123, brand new, at a very reasonable price. PM him.
cell_man offers these A123, brand new, at a very reasonable price. PM him.
coolchinateacher
100 mW
dumbass said:
Well shoot, I just typed up a big response to this and the computer ate it. Hate that.
I agree with you Bob but, that is the reality of life here. Paypal and even credit cards for that matter are not accepted. Paypals fees for transfering to RMB are outrageous!China has it's own version of a paypal type system that works well and protects the buyer even better. Even with that, most payments are direct bank-bank transfers which are very easy and cheap to do here. There are hundreds of thousands of ebike suppliers here. Very few take Western payment methods and those who do charge western prices while the other vendors sell the same products to the HUGE domestic market for 1/2-1/3 the price. The amount of quality product available here for cheap is incredible. There is also a lot of junk.
If I weren't living here I would not have used the suppliers I have and would have missed some fantastic deals. Without living here or knowing somewhere here I would have never found them in the first place and even if I had I wouldn't have been able to complete a transaction.
Living here I was finally able to find a way around the huge fees for money transfer thing... I'm able to use my paypal debit card here to either pull out RMB or is some cases I can do a direct transfer to suppliers using my card at an ATM here.
Holocene
100 W
The Cycle Analyst handles low voltage cutoff nicely. During setup, you select a minimum voltage. During discharge, if your pack falls below the threshold, the CA tells the controller to reduce the amp draw until the threshold voltage is restored.
I think you can download the CA manual from ebikes.ca it's a good read. The capabilities are impressive.
There is other advantage to buying 12V modules like SLAs or TSs: you can rotate the batteries in your pack. The first battery or cell in a series-wired pack takes the most abuse. I switch the lead-dog to the rear once a week, or twice during a very long ride.
With a duct tape pack, when the lead dog gets tired, the whole pack goes to dog heaven (unless you want to perform surgical intervention)
Do you have any friends who are IT admins? You might already have a source of free used SLAs (the common type used in computer UPS's). The CA will let you measure their capacity, put together a matched set and recycle the weak batts.
SLA's can easily be slung under the top tube of your frame triangle which will improve your bike's handling. 3 should fit length-wise on most bikes. 12V-12Ah SLAs weigh 8.33 lbs each, so 25 lbs for a 36V-12Ah pack.
I think you can download the CA manual from ebikes.ca it's a good read. The capabilities are impressive.
There is other advantage to buying 12V modules like SLAs or TSs: you can rotate the batteries in your pack. The first battery or cell in a series-wired pack takes the most abuse. I switch the lead-dog to the rear once a week, or twice during a very long ride.
With a duct tape pack, when the lead dog gets tired, the whole pack goes to dog heaven (unless you want to perform surgical intervention)
Do you have any friends who are IT admins? You might already have a source of free used SLAs (the common type used in computer UPS's). The CA will let you measure their capacity, put together a matched set and recycle the weak batts.
SLA's can easily be slung under the top tube of your frame triangle which will improve your bike's handling. 3 should fit length-wise on most bikes. 12V-12Ah SLAs weigh 8.33 lbs each, so 25 lbs for a 36V-12Ah pack.
kalpatarutree
1 W
- Joined
- Jan 4, 2011
- Messages
- 57
Mighty Volt:
Do you know where I could view a detailed, step by step process and guide to assembling and maintaining a123 batteries? Detailed, concise, instructions with pictures is the only way I can go into that world. Where to get the best a123's, how to assemble them, how to test them, what voltages are acceptable, etc. etc.
If i were to go all the way with that type of a setup, I would need to see, conceptualize, and understand. But I can already see the benefits of that route, although it seems way off in tweakyville - if one battery went out on you - you could just replace that one... which in the long run seems like the safest and most economically sound path. Mounting the batteries in the frame is sooooo cool as well.
Do you know where I could view a detailed, step by step process and guide to assembling and maintaining a123 batteries? Detailed, concise, instructions with pictures is the only way I can go into that world. Where to get the best a123's, how to assemble them, how to test them, what voltages are acceptable, etc. etc.
If i were to go all the way with that type of a setup, I would need to see, conceptualize, and understand. But I can already see the benefits of that route, although it seems way off in tweakyville - if one battery went out on you - you could just replace that one... which in the long run seems like the safest and most economically sound path. Mounting the batteries in the frame is sooooo cool as well.
dogman dan
1 PW
There's a reason for the sticky threads. this one, http://endless-sphere.com/forums/viewtopic.php?f=14&t=2498
And this one. http://endless-sphere.com/forums/viewtopic.php?f=14&t=17912
Are as good as it's going to get. Clear, consise etc doesn't happen much on a forum where the latest greatest thing changes by the month. But now that a123's are a lot easier to get ahold of, the assembly of them into a pack is not obsolete at all. A good a123 pack is a beauty to have. It was merely unaffordable for me in the size I need to have for the range I need.
And building your own, it's too much work for most of us. What you are planning is perfect for slap your money down on a ping 48v 20 ah, and strap it on. Done. If you are running a 25-35 amp controller, you won't need a123's as much as a guy running a more powerfull motor at higher amps does.
If you NEED the amp capabilites of a123, then most of us nowdays just go to lipo from hobby king. It's just worth the earlier wear out for us to keep the assemble 10x simpler. We don't bother much with bms's and just run the bikes with a low voltage warning device of some kind. Often we know we are going to abuse it all, and don't worry too much about the lifepan. For me, I race and dirt ride lipo, and commute to work on the pings I expect to last for many more years.
And this one. http://endless-sphere.com/forums/viewtopic.php?f=14&t=17912
Are as good as it's going to get. Clear, consise etc doesn't happen much on a forum where the latest greatest thing changes by the month. But now that a123's are a lot easier to get ahold of, the assembly of them into a pack is not obsolete at all. A good a123 pack is a beauty to have. It was merely unaffordable for me in the size I need to have for the range I need.
And building your own, it's too much work for most of us. What you are planning is perfect for slap your money down on a ping 48v 20 ah, and strap it on. Done. If you are running a 25-35 amp controller, you won't need a123's as much as a guy running a more powerfull motor at higher amps does.
If you NEED the amp capabilites of a123, then most of us nowdays just go to lipo from hobby king. It's just worth the earlier wear out for us to keep the assemble 10x simpler. We don't bother much with bms's and just run the bikes with a low voltage warning device of some kind. Often we know we are going to abuse it all, and don't worry too much about the lifepan. For me, I race and dirt ride lipo, and commute to work on the pings I expect to last for many more years.
kalpatarutree
1 W
- Joined
- Jan 4, 2011
- Messages
- 57
Great Dogman, thanks for clearing excess confusion!
Its beginning to look like that - Im in it for the distance, im not building a 72v monster that can go up hills or go 35mph. Im going to invest in a 48v 20ah lifepo4 brick, and try to take care of it. That way, hopefully, I wont have to tear it apart to fix a broken cell or something like that.
As for the weight distribution, I have a front hub motor, so "heavy in the front, heavy in the back, me in the middle" is just the way its going to be.
Ill post pictures and specs of the bike when im through with it, and remain connected to this forum. thank you everyone for helping me sort out the options in EV battery world.
Its beginning to look like that - Im in it for the distance, im not building a 72v monster that can go up hills or go 35mph. Im going to invest in a 48v 20ah lifepo4 brick, and try to take care of it. That way, hopefully, I wont have to tear it apart to fix a broken cell or something like that.
As for the weight distribution, I have a front hub motor, so "heavy in the front, heavy in the back, me in the middle" is just the way its going to be.
Ill post pictures and specs of the bike when im through with it, and remain connected to this forum. thank you everyone for helping me sort out the options in EV battery world.
dumbass
100 kW
kalpatarutree said:
If you are a newbie and want to look at doing an "in frame" pack you might want to consider cylinder cells with "bolt on" connectors. It avoids soldering and spot welding. And if you decide to add something to your setup it's fast and easy. In frame packs are great if you don't need to trasport your bike. In my case I trasport it to the forest preserve on my car. Some people toss it on the front of a bus and need to pull the pack off/on quickly.
Bob
dogman dan
1 PW
people scoff sometimes because you can do better, but actually the front motor, rear battery setup does work rather well. For slower long distance rides the handling compromises matter a lot less. Some times I load 50 pounds on the rear rack and panniers of my commuter and go for very long rides. I have to watch it with ruts in the road, potholes, gravel. Stuff that wouldn't faze me with 15 pounds can throw you with 50. But daily riding with 20 pounds back there can be adjusted to pretty easy.
999zip999
100 TW
My 48v20ah ping at 24amps. goes 28mph for 20 mls.. this is just fast enough 34mph with the 40amp. controller. Which is a little fast for me with my thight bearing steel bike alummiun does flexed. 40amps cooks my Ping but is still good. Test pilot.
Holocene
100 W
Hi, KT
Sounds like you've made a choice! You're going to get excellent results with a Ping 48V-20Ah pack. Compared to a car that gets 30 mpg, with $4/gal gas, you're $800 battery will pay for itself in 6 months (24 weeks)!
And if you average 0.5 C discharge, that 500 W of power will have you cruising on the flats at about 25 mph. Further, if you charge carefully and use a Cycle Analyst to limit the pack to 1C discharge, you'll still have 1000W of hill climbing power, and your pack should last about 3000 cycles
Over the 6 year life of the pack, you'll save about $10,000 for 2,500 gallons of gasoline, and prevent about 25 tons of CO2 from being released into the atmosphere. That's a 12.5 X ROI for your battery purchase
Welcome to the future my friend, I'm glad you've coming along for the ride 8)
Sounds like you've made a choice! You're going to get excellent results with a Ping 48V-20Ah pack. Compared to a car that gets 30 mpg, with $4/gal gas, you're $800 battery will pay for itself in 6 months (24 weeks)!
And if you average 0.5 C discharge, that 500 W of power will have you cruising on the flats at about 25 mph. Further, if you charge carefully and use a Cycle Analyst to limit the pack to 1C discharge, you'll still have 1000W of hill climbing power, and your pack should last about 3000 cycles
Over the 6 year life of the pack, you'll save about $10,000 for 2,500 gallons of gasoline, and prevent about 25 tons of CO2 from being released into the atmosphere. That's a 12.5 X ROI for your battery purchase
Welcome to the future my friend, I'm glad you've coming along for the ride 8)
Similar threads
