Investing in a new battery

[Kurt]

I am in the market for a lithium battery for my 48v ebike. The bike has been running on 4x18ah agm battery's for about 6 months .I only get around 6ah of useful power from this setup. At 17.9kg - 39.5lb they are not the best.

The bike is 48v and the controller was 33 amp but I am now using a 25 amp limit and I find this a good balance of power vs consumption. So its a 1200w max set-up that can be adjusted with my cycle analyst but I wouldn't want to go much lower than this on power.
I find my whkm can range from 9whkm to about 28whkm but average is around 20whkm. Range is important to me I need to be able to ride to the city and back on one charge thats a 30km round trip and there is a good mix of hills and flat section.I have done this 30 commute on as little as 5ah of battery but i did a lot of peddeling I think the whk was only 6 but a lazy ride should still fall within my 20whkm average. So I am looking at around 300whr min-to hot to swetty 600whr relaxing for my commute.


48v 20ah ping battery is 960wh and with vms and charger I think is around $750ish US delivered depending on postage cost at the time

There is another option I can get the hi spec grey BMI single cells for about 32 of them for $1100 US but would need charger and BMS I think the charger is about $250 US so 1350us plus vms system $?

BMI also do a factory pack battery 10ah 48v pack same cells that is complete with inbuilt vms that can connect to pc and show all kinds a specs. it is packaged in a black plastic hard box all very tidy and ready to go for about $ 600 US plus $250 for there 7amp charger . But it is only 10ah

I Know the BMI factory pack even at 10ah will take anyt amount of amps I can throw at it and last a long time but I can really only afford there 10ah 48v pack . So that draws me to pings 20ah packs. help me make up my mind :? or other options . I was thinking get the BMi and if its not big enough get another pack later although at 8.2kg each that would be 16kg kinda heavy for lithium. This allso got me thinking why is pings 20ah 48v pack 10kg and the bmi pack is 16.4kg?

lots to think about.

Kurt

 

[Gregory]

These BMI (PSI) cells have a solid aluminium shell where the Ping packs have foil pouches. I assume thats the weight difference.

Interesting to hear BMI do a 48V10Ah pack with 7a charger for $850. Cyclone is selling similar with a smaller charger for $100 less. I bought this and punish it at 6C - 60A.

For a 25A max draw the ping pack seems damn good value. Buy that, you could always re-sell it.

 

[Kurt]

I just had a look at the cyclone web page they want $200 US for shipping so that is $950 US delivered so that is $1300 Aust. The cells are also the older style green cells apparently that are of a lower spec.

The guy I was talking to in Sydney would do the 10ah 48v for $1200 Aust its the over all Quality of the packs that I havn't seen anything on the market that comes close.

The ping pacs come out at about $1050 deliverd but 20ah size

The Aust $ is all over the place at the moment it was almost 1 for 1 a couple of months ago.

 

[dogman dan]

My gut feeling is that you want the higher amp rating battery, so either the BMI if 10 ah of range is enough for you, or the Ping, but in a larger sise, like a 30 ah, if you want to make real long rides. 25 amp limit is well within the range of the Ping 20ah battery, but really, aren't you going to want to make that amp limit higher if you can? Maybe the 24ah as a compromise?

I"m a big fan of Ping, but if you can afford it, get the bmi cells, they are clearly more adaptable to whatever bike you may get next year.

 

[Kurt]

The hardest thing is judging how the bike will feel with lithium power. As my only experience is with cheap sla packs .Today's 40km ride, 15km to city 10km around the city and 15km home. The first 15km to the city I really tyred hard to save as much power as I could on a 250lb total ebike/rider/trailer set up .I did that 15km on only 1.25ah and then did 10km of riding in the city very flat land and only used another .5ah my whkm was at 2.6wh km .

The 15km ride home started to use the throttle more and more but at the 10km mark the voltage was starting to really sag a lot. I used about 3.5ah to come home. total AH was 5ish and the battery's were toast.I think my sla packs do a better job of powering my car refrigerator than a ebike.

I think I could do the trip there and back on 8ah and it would be a nice comfortable ride . So 10ah size is ok but as long as the pack could give strong output for 8ah without voltage sag. 1200w is enough to do 40kmh on the flat and get me up any hill.



I am thinking 2000 cycles at 8ah discharge 30km ride each day is 5 1/2 years of use and 60,000km of riding that sounds ok to me.Truth is I wont will ride it every day. It would be interesting to know what the shelf life is on the battery's as in you have to use up all the cycles in so many years or they will just self decay.

As for the ping packs. I think his business ethic is great and I don't have any concern about him solving any issues to keep every one happy but. If you are going to spent $1000 Aust on something you don't relay want issues in the first place like ,fatly bms , dead cells,inflated cells,unknown life expectancy,faulty chargers. These are just some of the issues I picked up on that some people had. Seemed like ping went out of his way to solve all of them. They just seem a little fragile over the long term as in a couple of years how robust everything was and much trouble I would have to go through to keep it running strong.Will I get anywhere close to the 20ah rating from the pack. I would expect to be able to use 9ah from the BMI packs so would i get 18ah from the ping 20ah?

Kurt.

 

[powermed]

Hi Kurt, can you charge in town? Getting a pack that can handle high amps charging, and charging in town for 30 minutes might make good sense. To that end, a pack based on A123 or Prius cells would do it easily.

Your commute sounds much like mine. In town I stop at a coffee shop I like, have a coffee, plug in and read the paper for 30 minutes, or say hi and grab a bite with my buddy that runs a greek sandwich shop and plug in there. If I pedal a bit and don't run at more than 75% power, I don't really have to even do that for the 10k round trip (44v at 6.5AH Prius). Carrying around enough lead for a round trip is a non-starter IMHO, and typical NiMH packs take too long to charge unless you're in town all day.

I think if anyone can charge at the half way point, a "50% solution" is worthy of close study based on significant cost and weight savings. I don't worry about pack life with A123 or Prius cells - years is fine by me since I've little doubt I'm going to change technologies in 3-4 years anyway.
z.

 

[ZapPat]

[...]Will I get anywhere close to the 20ah rating from the pack. I would expect to be able to use 9ah from the BMI packs so would i get 18ah from the ping 20ah?
Kurt.

Check out the Ping 2.0 thread for my recent ping battery tests to help make up your mind. As for your question, you will have no problem getting at least 18-19 Ah capacity from a 20Ah Ping pack when run around 1.5C average continous (so 30A for the 20Ah battery). Of course if you want to save on weight and money, and are sure you won't ever want to have more range with your bike than your current needs, then maybe you could go for 16Ah. He can build anything in multiples of 4Ah, so you choose.

Of course the PSI cells will give you less voltage sag (maybe 1/3rd) than an equivalent Ah ping pack, BUT the weight of the PSI cells is 1.6X more than ping's and they also cost 2X more, so getting extra Ah capacity with a ping battery might be better (and give you that much more possible range!). Another bonus of using less Amp-hours of your total capacity is prolonged cell life, as dogman rightly points out. At any rate, after riding around with your lead, even a ping battery will feel like a god's blessing, garanteed! :wink:

The only thing I would have changed with my Ping battery order would have been to get the battery made into two seperate blocks to make placement on the bike more practical.

 

[Ypedal]

Going from Lead to Lithium is a huge upgrade..

If you go with the BMI/PSI, you can count on a usable 9ah on the wattmeter.. holding flat solid voltage.. expect 48v to the controller for most of the ride.

If you only need 30 km range, 10ah is plenty. the bike will be lighter ( easier to pedal, and your efforts are more pronounced, no harm done leaving the bike sit with a half charge.. )

With 20ah of Pings, you could do the trip twice .. but do you ever honestly do 60 kms in a day ? or would you if you had the power for it ?

Less bulk, less weight, better quality, rules to live by ! :wink:

 

[Kurt]

Charging in town isn't an option . Although I am sure prius cells are great if they are new gen III with steel sides and you charge them correctly after spending a couple of hundred $ on a full prius pack that turned out to be past there used by date and all of no use to me I just don't want to go there any more .

The 18ah from the ping pack sounds good just kinda scary to spend $1000 on something warped in duct tape and your only backup is one man in china. Even though he is very reliable .

I am going to find out what the cost is to build the 48v 10ah BMI pack myself using 16 individual cells and there VMS/BMS .If it is a little cheaper than buying there factory built packs and not weigh as much I am starting to think this would be my best option. This way I can build the pack to what shape I want and if I find I need more than 10ah capacity I could build another 10ah pack later on . and balance them on the bike could even go 96v as a option :lol:

It seems like I would need 16 cells and 4 of there VMS boards copper bars and so on.I also like the charger on offer that is 7amp output I think so 1 to 1.5hr charge time sounds nice


My gut is saying go for quality not quantity. As I am just thinking of things that my wife and I still own today that we purchased 10 years ago and I don't think any of them were cheep.

Kurt

 

[pwbset]

If you're looking for 10ah or less consider lithium cordless tool packs too, which you may be able to find a cheap local deal on. 10ah @ 48v really is a good amount of battery if you think about it. I go 14km on around 5ah/400wh @ 84v with moderate pedaling and a very steep, long hill that climbs 490m non-stop. Lithium is awesome.

Having said that nothing sucks worse than climbing a mountain only to run out of batteries with 1km still to climb and a 28kg dead weight bike. Haha! That's why I'm building a 7.5ah batt for a little better buffer on my "lazy" days. :wink:

Bottom line is only get what you need + 20% "I'm really tired today" buffer.

Like YPedal says (listen to him he's a really smart cookie):

Less bulk, less weight, better quality, rules to live by !

 

[miro13car]

Kurt,
how do you get $600 figure for BMI 48V 10 Ah.
Are you sure?
As I figured out LifeBatt line and BMI line of batteries are identical except label on the top.
I saw pictures from Australian web site selling BMI packs.
Am I wrong here?
For sure they use same VMS boards, connectors and cells.
LifeBatt charges $750 for just 36V 10 Ah pack plus $175 for 8A charger.
jUST gOOGLE "LifeBatt" and you will see they prices.
Again the same 8A rating, to many coincedences here. They must be same packs , batteries except simply labels.
nOTHING wrong with private labeling.
My conclusion is thet they are all made by PSI????
Can you answer?
Anybody has any info?
MC

 

[mcstar]

Again the same 8A rating, to many coincedences here. They must be same packs , batteries except simply labels.
nOTHING wrong with private labeling.
My conclusion is thet they are all made by PSI????
Can you answer?
Anybody has any info?

You are correct micro13, they are exactly the same product. The ones you get from Tiawan directly (or through Armin in Au) come with the BMI label. LifeBatt has them attach their LifeBatt labels to the exact same cells and packs and they just import them for to the US. I just got a shipment from BMI of cells this week. The latest ones from BMI have the black label like the ones on my site.

Kurt, I totally agree with you on going for quality. In my case the ping pack solution only lasted about 6 months. To be fair, I ride very rough rodes at high speed. My 48V 10Ah pack goes about 25 miles at full throttle (25-30mph). I can get 30-35miles if I back off the throttle a bit and cruise at 22-25mph. Check to the link to my e-bike site in my sig for pictures of my setup.

Enjoy your new batteries!

 

[recumbent]

In my case the ping pack solution only lasted about 6 months.

When my LIFEPO4 batteries were pumping out 10ah's of current, I could travel 40 KM's, no pedaling.

Although I recommend buying quality over price, never have i seen anybody get more than 1,000 cycles from a set of LIFEPO4 batteries and hold their original AH rating.

 

[miro13car]

mcstar,
Yes, but $600 for BMI 48V10Ah???
Is it true,
Your web site doesn't show any link to BMI or PSI.
aNY LINKS TO WEB SITES?
MC

 

[Kurt]

The guy gave me a price in an email of $895 Australian = with about $40 Aust shipping he said the price stands for 7 days.

This was for a 10ah 48v BMI factory pack hard case with inbuilt vms. It works out to be $627 US .

Then the next day after sending a couple of emails back and forth asking questions about single cell price and trying to work out what would be the best deal for me before I handed over the my cash. I made my mind up that I didn't want the single cells and wanted the pre built factory pack for $895 Aust I sent a email asking to send me a invoice so I could buy it. I got a email that was about $1300 and about $300 of shipping and other logistics and so on.

I sent him an email back asking why the change in price after not even 24hrs and I copied in his previous email with his 7 day deal of $895Aust + about $40 postage.

He replied to say that deal didn't stand any more and he had pulled that factory pack apart to use the vms for an urgent! order. This is like 12hrs after he sent the email that the deal stands for 7 days.

This is also after telling in a email me you cant pull the factory packs apart to get at the cells.

There was a couple of other things to that didn't add up small things just $5 or $10 differences in price for the charger that seemed to change in every quote over 3 or 4 emails. I didn't like that .

He also said that people always complain about the price. I didn't complain I just wanted to find out some of the prices to get a battery to my door and a bit of info on the different options he was selling. So I don't know what the hell happened.I didn't pursue it any further .

I went the next day and ordered a Headway 36v 20ah pack from a different place.
Kurt.

 

[GGoodrum]

Since you are in Australia, I would definitely talk to Armin. He's got direct access to the latest BMI cells, and orders them in quantities large enough to keep the costs to a minimum.

One thing you should be aware about the BMI/LiFeBatt VMS board. It doesn't have an active cutoff circuit for the LVC function. These things are designed to be used with multiple boards in series, which are daisy-chained together. There is a TTL logic signal that goes high, when a cell is too low, but this can't be used directly to trip the brake signal on most ebike controllers, which typically require the signal line to be grounded, in an active condition. In order to do the same thing, you'd need an extra circuit to invert the VMS signal, so that the controller line can be pulled down. I'm pretty sure that BMI/LiFeBatt have done such a board, because I see now that Dave, at Electricrider.com, is offering BMI/LiFeBatt HPS packs with this extra board that is integrated into new setups.

-- Gary

 

[miro13car]

Kurt,
that's quite shoddy practices YOU DESCRIBED HERE I would say.
I paid US$750 for 36V 10 Ah battery and US$175 for 8 A charger
from LifeBatt Las Vegas USA and Don Harmon offered me money back if I don't like what I got.
He sent me replacement charger at NO cost to me , returning my shipping cost of old charger.
I got a problem like everybody dealing with LifeBatt packs with scanty, bad English tech documentation, very limited in words, no explaination how VMS works. Example VMS registers #of cycles, and learns , I didn't get beeping for like 10 chraging and no end of charge LED. After like 10-15 charges VMS started to work with beepings like described, but manual doesn't say that how it suppose to be.
Any links to BMI or PSI WEB SITES?
MC

 

[mcstar]

but $600 for BMI 48V10Ah

I'm not sure if you can get them that cheap, but if you do please let us know. I paid about $1000 for a 48V 10AH pack with VMS. I've never had any issues like Kurt is describing. I do know that the fluctuating markets are reeking havoc on the exchange rates right now. Armin is having to juggle exchange rates between three countries and shipping must be factored in as well. Some of us have been going in together and purchasing cells in combined quantities to allow us to save on shipping costs. That has been advantageous for us lately. I just got a shipment in this week and we had no issues on the pricing. The per cell cost works out to about $55/cell once you factor in shipping. Gary is also correct about the VMS though. I does not do LVC. I'm currently using a BMS from a ping pack on mine and it works fine. Ping sells them for $50 or so.

I don't think BMI has a web site, at least I haven't see it if so. They are a manufacture and deal mostly with large orders (1000's of cells) made by companies using them in vehicles.

 

[Kurt]

Unfortunately it was Armin I was dealing with.
kurt.

 

[Ypedal]

I beleive Armin used to be part of the lifebatt group.. but not any more.. i do not know the exact reason why.

The BMI are exactly like my psi cells.. they ARE psi cells !! and from the grey shrink on them i would say from an order purchased when he was with lifebatt..

Why can't people just tell the darn thruth ( i'm sure there is a long saga behind it.. but in the end. the truth always comes out eventually.. this is the internet age baby !! )

 

[paull]

Given that the AU dollar is in free-fall, maybe Armin should start giving quotes in his supplier's currency

http://finance.yahoo.com/currency/convert?amt=1&from=AUD&to=USD&submit=Convert
http://finance.yahoo.com/currency/convert?from=AUD&to=TWD&amt=1&t=1y

 

[mcstar]

Given that the AU dollar is in free-fall, maybe Armin should start giving quotes in his supplier's currency

Great idea Paul. It seems your voice has been heard.