Please help me with battery choice

[silentfoster]

Hi guys!

It seems like my cellman, MAC rear kit has finally arrived!!!
I havent pick it up yet but I got the USPS notice of a parcel from china, so it must be it...
I am finishing school TOMORROW and I can start putting it all together.

Now, I have not purchased a battery yet. So I would like some recommendations. I am more interested in first, range, second torque and speed is the least concerning. I saw this little nicely designed battery in ebay...

http://www.ebay.com/itm/36V-Electric-Bi ... 9411wt_952

I know it will be probably not enough but I wonder what you guys think...

Any one can tell me the actual time for delivery of PING batteries? others?

Thanks

S.F, California

[ohzee]

that battery looks like it's 36V 8.33 Ah - so it's not going to get you very far.
I ordered a few things from ping and he got them to me within 5 days.
Go with someone known from here.. ping , cell_man etc.. or if you buy off ebay
just don't plan on any replacement or technical help.

GL

[wesnewell]

At only 300wh it won't get you far. if anywhere. What's the amp draw of your controller?

[dnmun]

if you wanna buy an ebay battery go look for the sun-thing lifepo4 specials. they are the cheapest deals we have seen here for batteries and they ship from china by surface so the shipping is super cheap. the 48V20Ah pack that someone mentioned here was only $500 delivered. i don't think anybody can beat that and they are really lifepo4 and not some "lithium ion" labeled pack.

i lost the thread, but you should find them by searching.

[SamTexas]

http://www.ebay.com/itm/36V-Electric-Bi ... 0919882064?

The ebay seller grossly and shamelessly exaggerates the discharge capability of that pack.

Very Powerful: continuous output up to 460W, maximum burst output up to 1000W.

The cell used in that pack is Panasonic CGR18650CG. It's mainly designed for low power devices and mainly used in laptops, very common in Dell's and Dell's clone battery pack.

Continuous output of 1C (300W) is already pushing the cell's limit. For that pack to last, continuous output should be 0.5C or 150W. Very usable for TRUE pedal assist ebikes where the rider and the motor contribute equal share of the required power.

[Ykick]

Please provide the power of your kit? If you're not sure, ask Paul. Those eBay packs and Ping's aren't intended for high power setups. Even with a 20-22A controller most of those packs are working at near their max.

I question the wisdom of not going with a Cellman A123? It's not that much more money, is it? It will work well for your kit over a very long period of time.

[dnmun]

ok, found it:

http://stores.ebay.com/sun-thing28/LiFe ... 34.c0.m322

[dogman]

Yeah, that battery in the top post is far to undersize to provide for a Mac kit. It will come with a 20-25 amp controller I believe. You need a 15 ah size at minimum, unless you buy a battery with a better discharge rate.

So a ping 15 ah, or simlar size similar lifepo4 pack is a minimum. My rule of thumb for 36v batteries is 1 ah per mile range, at about 25 mph.

The sun thing pack is quite a bargian. Interesting to see the duct taped lifepo4 pack still exists. Don't count on any CS at that price though.

[dnmun]

actually someone has already mentioned how they called him on skype and got really good support.

the guy who originally posted the ebay ad was also talked out of using this source by the EXPERTs. i had recommended he contact sun-thing and see if he would break the 48V20Ah pack into two pieces, a custom pack like ping does. but he dropped outa sight.

nobody has ordered from him and posted up about these packs yet but they look just like what ping makes up. maybe if you are interested, contact him and ask him to send you a picture of the BMS and we can offer opinions about the BMS.

expect 2C from these 5Ah pouches.

[parajared]

lifepo costs a lot up front, but will save you money in the long run. The problem with it is it's discharge rate and repairability (excluding meanwell, a123). You can only pull like 20-30 amps out of the little guys, which means no mountain off-road trail riding use for you, and if you have a cell go bad, most lifepo packs are difficult to pull apart and repair, so you just end up dropping another $600-1000 to get another one (a123 packs are easier to repair).
Ping seems to be the way to go around here for lifepos

lipo doesn't cost as much up front, discharges high amounts of electricity even on cold days, and is easy/cheap to swap out bad cells, but is long term expensive, flamable, and complicated to wire up and balance. People who run lipo tend to have these wild octopus looking battery cables connected to their batteries, and usually charge their batteries in a rather complicated way. If they want to balance their batteries (a good idea if you are opposed to your batteries bursting into flames) they end up with either a fair amount of fiddling around with wires, or a complex multi-cell charging system.
Hobby King is the way to go for the lipo build

Here's my lipo math assuming your battery only makes it to the worst case minimum cycle life (hk vs ping on 48v 20ah):
lipo= about 85 cents a cycle
lifepo= about 42 cents a cycle

If you are a gambling man you can give conhismotor.com a try for around 32 cents a cycle.

[SamTexas]

..., and if you have a cell go bad, most lifepo packs are difficult to pull apart and repair, so you just end up dropping another $600-1000 to get another one...

Why? I just opened one up for repair and it was not at all difficult. A cell is a cell, regardless of chemistry.
http://endless-sphere.com/forums/viewto ... 27#p591795

[dogman]

Well, that's good to hear about sun thing providing some CS. I would love to see another really good supplier of batteries with the same type cells as pingbattery. Maybe it would drive pings prices down just a bit. A LOT of battery vendors have come and gone, and a LOT of them knew nothing about the product they sold. Another one to add to the very short list of good vendors would be a very good thing.

I am no expert on batteries. As electronics go, I'm clearly a moron. I just know two pingbatteries I have owned have been the lowest cost per mile batteries I have owned to date. The worst, lead acid. Worst after that,8 ah nicads. And I've killed some RC lipo pretty fast too, with dumb mistakes. But my pings, used within reasonable limits have gone the distance. 700 cycles from ping one, which was true 1c cells. 220 so far from the second one with 2c cells.

Simple repairs to a ping, or the similar sun thing battery are easy, replace a bms, or reconnect a wire. But replacing cells from the center of a 48cell battery pack is no picknick. I do wish these guys would make them a bit more modular, and easy to swap out a cell group on. Some are, but pings are soldered into one big lump.

[NeilP]

I was total newbie when I started with e-bikes an couple of years back..and went straight in with LiPo, it is do-able even for a newbie...just be careful, and read the newbie facts about LiPo
viewtopic.php?f=14&t=26621

Battery protection and the octopus of wires just got a whole lot easier thank to Patrick (methods) and his parallel/protection kits.
http://www.methtek.com/category/battery-protection/

if you were to get his kit boards and your pack was not above 14 series, (so max 58.8 volts) you could create a pack that you can balance charge without dis assembling the pack if you had a Hyperion charger that does up to 14 series.

the boards from methods do LVC and HVC protection, so they cut out the bike if any cels goes below voltage ( 3 volts I think) The HVC cut out would not connect direct to the Hyperion,but it would cut the charge to the pack if any cell did go above while charging with the Hyperion, if you were not using it for balance charge at the time.

two of his 6s boards would allow you to build a 12s pack of up to 7 parallel, though I guess to start with, 2 or 3 parallel would be enough

4 of these for $45 each = $180, plus two of methods boards 2x $50, plus a bit of extra for wiring....$50 for the main harness would be plenty for cable and plugs
http://www.hobbyking.com/hobbyking/stor ... duct=16803
would give you a 10 Ah pack capable of 150 amps ( 15C ) ..another $90 for 3 parallel and 15 Ah

[SamTexas]

700 cycles from ping one,

That's good but still far from the advertised life cycle, right? Who has the most cycles on their LiFePo4 pack? Please post current cycles and vendor or type. I wonder if anyone has passed 2,000 cycles on their A123 pack?

[wesnewell]

Most pouch likepo4 cycle life is rated at 1C or less discharge. RC lipo is rated at it's constant C rate. Only pulling ebike type C rates. which are usually less than 5C, rc lipo should do as many cycles as lifepo4/ Remember, those 1000 cycles for lifepo4 are at 1C or less discharge rates. I can't count the number of lifepo4 packs gone bad here in the forums, but it's a bunch, and most with a lot less than 1000 cycles on them. It'll take me 10 years to get 500 cycles on my lipo and I'll probably be dead before that happens. Besides, I like the size, weight, and flexibility of rc lipo compared to lifepo4.

[SamTexas]

...Besides, I like the size, weight, and flexibility of rc lipo compared to lifepo4.

I think everyone agrees with you on the advantage in size, weight and discharge rate for RC LiCo. 500 cycles is ok with you (if RC LiCo can actually live that long) but definitely not ok with me. But the main reason most people (me especially) have second thought about RC LiCo is the thermal runaway risk.

A123 (LiFePo4) is safe, has more than acceptable discharge rate and is cheaper than RC LiCo (if A123 truly has 2 to 3 thousand life cycles). The only thing it can't compete with RC LiCo is energy density. But then RC LiCo's energy density is way inferior to consumer LiCo's. It's always a compromise.

[NeilP]

To give you an idea of LiPo cycles and cost...an this is on going and getting better every charge...
My pack is 20s4p Nano Tech LiPo (the expensive type of LiPo)
It cost about $1200 US dollar to build

is now up at 316 cycles, no sign of loss of capacity and 5800 miles, so 20 cents per mile at present plus electric recharge cost..minimal. cost per cycle is expensive at present, $3.80 ...It is going to come down, but i do not see it getting much cheaper than $2.00 per charge cycle, assuming 500 plus re charges.

[SamTexas]

Good, realistic data NeilP. Man that's expensive. In my mind, $0.10/mile is the absolute upper limit for battery wear and tear.

[NeilP]

Not when you compare it to driving a car or 4x4
And that is current figures..I can easily see getting plus 500 cycles on this pack..so that will bring price down...
AND.
I bought Nano Tech LiPo, because I wasa newbie and did not do enought research and realise they were so expensive...I bought them because they were 10 s packs..If I had bought the 15C Zippy packs as I linked to earlier cost would have been a lot less. Also since I bought, I think prices have come down a bit for LiPo. So your costs will not be near mine

What size pack were you thinking of going for..we can work some prices and recommendations for you to help out..

A mate built his pack ( had it built by Jim Delgado) to the similar capacity to mine out of Headway Headquarters 10Ah cells.
He has cells in the frame and in the rear carrier...twice the size and weigh of my LIPo pack.

[SamTexas]

Not when you compare it to driving a car or 4x4

That would be apples to oranges, right? I would compare it against a small ICE scooter.

Honda CBF125 http://www.honda.co.uk/motorcycles/125cc/#!/cbf125/
Honda Innova 125 http://www.honda.co.uk/motorcycles/125cc/#!/anf125i/

What size pack were you thinking of going for..we can work some prices and recommendations for you to help out..

Just discussion and fun for me. I have more battery than I need at this moment. I do want to play with A123, but again just for fun and out of curiosity.

[NeilP]

I am comparing to what I have and what my bike is replacing.

These are my choices, electric bike, 4.0 litre diesel 4x4, small car or 1200CC Harley . My e-bike replaces my 4x4 for every day transport.

But I do get your point, but I can't compare as I have no idea and not worked out the cost of a small scooter.
But you will probably have better performance than a small 50cc scooter, and you can take it on cycle paths too, where the scooter only on the road, so even if it is more than a small scooter, in my mind, it is still a winner

[NeilP]

Just discussion and fun for me. I have more battery than I need at this moment. I do want to play with A123, but again just for fun and out of curiosity.

Sorry, I should have directed that bit about working out the costs of a LiPo pack to the OP (silentfoster)

[SamTexas]

But you will probably have better performance than a small 50cc scooter, ...

That's why I did not list a 50cc scooter. The two I listed were 125cc.

..., and you can take it on cycle paths too,

Agreed.

[NeilP]

Depends where you live too I suppose and the cost of fuel in your area.

here unleaded is $2.26 per litre so $8.56 per US gallon

.That's why I did not list a 50cc scooter. The two I listed were 125cc.

depends on how far you push your e-bike..mine out performs most standard 125's as well

[SamTexas]

$8.56 per US gallon

Even at that astronomical price, fuel cost for the 125cc scooter is still way below your battery wear and tear cost.