LiFePO4 Battery Showdown!

[oatnet]

It would be a very strange thing to get a virus from visiting a legitimate business website.

Not so - in fact legitmate business websites are hacked regularily and setup to distribute virii on users who expect them to be safe. Welcome to the age of the worm, you don't have to download porn to get infected anymore.

Freddy, you might want to check YOUR computer. Our web provider had their programmers look into this and found NO VIRUS present on our website. It would be a very strange thing to get a virus from visiting a legitimate business website. Just so people know - there is no reason to believe this report from Freddy!

Thanks,

Don Harmon

Oy, nothing like an amateur telling people to ignore virus warnings. Just so people know - BELIEVE THIS REPORT FROM FREDDY. If you didn't get a warning, upgrade your virus scanner! I got an alert for the same virus on my computer when I opened page 13 of this thread (*** = deleted for security):

====================================
Scan type: Auto-Protect Scan
Event: Security Risk Found!
Threat: VBS.Mondezimia!html
File: C:\Documents and Settings\*****\Local Settings\Temporary Internet Files\Content.IE5\V2CZF5K1\LiFeBATT%20Web_4[1].htm
Location: Unknown Storage
Computer: ************
User: ******
Action taken: Clean failed : Delete failed : Access denied
Date found: Tuesday, October 30, 2007 1:39:01 PM
====================================

I did not click on the link to Don's website, only page 13 from this thread. I don't know if my browser attempted to preload the link, or if it is on ES, or if it is a false positive. The filename is the same as the first CONTENT link on that page, but the link as shown on page 13 is clean. I looked at the file indicated in the message above, but it is a 0 byte file.

-JD

 

[Freddyflatfoot]

Thanks Oatnet,
wasn't really appreciating being dumped on, just for being the messenger!
Appreciate the comments, and I do hope all are listening and take some action, rather just putting their heads in the sand.

 

[Battboy]

Like I said this morning Action was taken - Our Server is clean. No Virus was found! We have no further problems being reported and no other way to explain this ?

I am sure if you go to the site itself - you won't be getting any alerts. Maybe it has something to do with a link previously posted on ES ?

Don Harmon

http://www.lifebatt.com

 

[Freddyflatfoot]

Possibly Don, I did suggest that earlier. Seems others have had same problem with the link.
May not be a problem with your site, just a virus attched to the link.
Moderators? Any way of checking this out?

 

[Battboy]

Be interesting to know how a Virus gets attached to a link ??? Seems the best course of action would be for the Moderators to just delete this post that has the problem ????

Not being an expert in Virus Protection - that would be my best suggestion.

Don

 

[fechter]

What link is this you're talking about?

 

[Battboy]

I believe it was confined to the link or links the I posted on page 13 of this forum Topic ???? Accessing the sight through the internet produced no flags ???? That's my understanding anyway.

Don

 

[Battboy]

We have a limited quantity of the Lifebatt 40138 Large Format Cells now in stock in Los Angeles, and are waiting for the VMS Boards & Chargers to arrive later this month. For those who may be interested all the details are listed on the Lifebatt website including the different Warranty programs available.

Attached below is a Lifebatt Initial Capacity Test one of a series being conducted @ Sandia National Labs Power Sources Development Dept.

Other independent tests are ongoing by Bob Mcree who posts here from time to time and has already posted on this sublject.

Best,

 

[efreak]

hi Don

I have a question, on this page

http://www.lifebatt.com/LiFeBATT%20Web_4.html

"Single pack orders will include shipping, direct from our distribution center in Los Angeles to the customer, and this is included in the price. "

near the top it says that shipping is includedm but each line has a price and a plus shipping?!!

How come?

efreak?

 

[Battboy]

Because that is for COMPLETE PACKS which aren't available yet. When we split into Individual Cells , VMS, & Chargers, due to popular demand, we had to make Shipping a + item. The Warranty also had to change to a three tiered Warranty Program.

THe Cells are available NOW and shipping from Los Angeles, so the shipping cost won't add all that much by UPS Ground.

Best,

 

[efreak]

my apologies i misunderstood!

the first three lines have that included they are the packs ok i got it now ty

efreak

 

[Battboy]

NO PROBLEM! Even I get confused lately

Best,

 

[bobmcree]

i have put a LifeBatt cell through 100 cycles now of charging at 10A (1C) and discharging at 20A (2C)

i have seen a slight INCREASE in capacity and DECREASE in impedance, with a corresponding higher output voltage.

Sandia labs is doing accelerated testing that should show whether the 3 year warranty is just insurance at extra cost or if it reflects the true performance. It is a bit premature for me to comment on longevity, but so far these cells look great.

i have been using A123 cells but it takes 4 to equal 1 LifeBatt cell in capacity and that certainly simplifies the wiring.

i have been paying about $100 for new 36V dewalt packs and cutting them open to get the A123 cells for $10 each. They can be had a bit cheaper if you spend some time on ebay, but probably not much less.

If i bought the cells from A123 they are almost $20 each. that makes the LifeBatt much less expensive. The only place i know of selling A123 packs that could be used for ebikes is charging almost $20 per cell with no bms

Gary G has been building some simple inexpensive low voltage cutoff bms systems i designed, that assert the ebrake when any cell goes below 2.1v under load which is LifeBatt's recommendation. I think he is selling kits, or the schematic is posted. He has now expanded the same design to cut off high rate charge when the first cell hits the preset level. My understanding is that if a simple aftermarket system like this is used they will warrantee the cells for 2 years. I have not seen the latest version of their bms, but the preliminary data looks promising and if you use these I believe the 3 year warranty applies even on the non-packaged "soft packs"

i have deliberately overcharged the LifeBatt to 5v and left it on the supply overnight with no heating or other problems, and it does not seem to have been damaged.

the simplicity of designing a system with 10 Ah cells vs. 2.2-2.4 Ah makes the LifeBatt much simpler to use, and the threaded studs on the cells eliminate any need for soldering, a huge benefit.

Are they expensive? sure. Are they worth it? the jury is still out, but they have been very open to independent testing and the 3 year warranty means a lot. They are less expensive than A123 cells unless you obtain them by cannibalizing power tool packs.

I paid $3500 for my first portable PC, a 20 lb compaq with an 8 meg drive and a 9" monochrome screen. I paid $1000 for the last one i bought which is 1000 times more powerful and 1/3 the weight with a fantastic color screen 4x the size. Early adoptees pay a price for innovation, but if you want the best technology around you have to pay for it or wait

I do not work for LifeBatt or get paid by them for endorsements. I am not 100% convinced they are the best deal around, but if the accelerated testing Sandia Labs is doing turns out well i might change that.

 

[efreak]

Thanks bob I am sure there are alot of people waiting for these results and I certainly appreciate it.

I remember I paid 3300 for my first computer it was an atari st1040 with wait for it ...ONE meg of ram and a huge 12 inch COLOUR monitor and did i ever look like a geek to my peers

thanks
efreak

 

[fechter]

Thanks for the test results Bob. I'm watching closely, since I'm in the market for new batteries.

Now.... where's that service center?

 

[recumbent]

Thanks Bob for keeping us in the loop, I'm another battery consumer, again in two months time. 16 lifebatt' (or similar) to start, but would like 20 AH so 16 more ideally, but the cost is too painfull all at once.

Will the Cycle Analyst from Justin not limit the Amp Hr draw? If we set it up properly.
Or
Are you going to make-up some of those simple BMS boards you designed for us to purchase?

Sure would be nice for everyone if these batteries work as well as we hope.

 

[GGoodrum]

Are you going to make-up some of those simple BMS boards you designed for us to purchase?

I actually have the 10-cell versions of the simple LVC boards available now, for those who want them: http://www.tppacks.com/products.asp?cat=26. They work great, and have already saved me from killing some cells.

Right now I'm selling these as kits, but I can do them pre-assembled and tested, for those that are soldering iron challanged. They are actually not that hard to put together. The instructions are here.

I'm working on some a123-based construction kits, that will include the LVC circuits, but these aren't quite ready yet. I'm also planning on doing some kits for LiFeBatt-based packs. These will basically be some heavy-duty PCBs that will bolt on to the end of the cells, and that will have the LVC circuits built-in.

-- Gary

 

[EMF]

I'm working on some a123-based construction kits, that will include the LVC circuits, but these aren't quite ready yet.
-- Gary

Do you have an idea when this kit will be available..I'm getting bored and need something to work on. :wink:

Also, is this construction kit going to incorporate the idea of using the high amperage primary charge then drop to the single cell chargers? 8)

 

[GGoodrum]

I'm working on some a123-based construction kits, that will include the LVC circuits, but these aren't quite ready yet.
-- Gary

Do you have an idea when this kit will be available..I'm getting bored and need something to work on. :wink:

Also, is this construction kit going to incorporate the idea of using the high amperage primary charge then drop to the single cell chargers? 8)

Soon, but I'm still working on trying to figure out how to build packs with the least amount of labor involved. I'm also playing with different form factors, which affects what the boards want to look like. I started out with the configuration shown below, with four packs on their side, end-to-end:

Each board connects two packs in parallel, using the plugs off the DeWalt BMS uits. Two of these boards are then connected in parallel, so you end up with a 10s4p pack. Just one of the boards needs to be populated with the LVC parts.

While this setup has worked quite well for me, on my folding bike, using two of these 10s4p packs in series, I decided I really wanted to reduce the assembly time even further, plus I wanted to be able to have more flexibility in how the packs go together. For instance, I really want to be able to do 4p, 5p and/or 6p setups, using the same basic building blocks. Basically, I want the DeWalt sub packs to placed upright, in a side-by-side configuration, so that if I want a 5p configuration, I'd have 5 packs side-by-side. I did a new LVC board layout that fits between the plastic end caps:

This would go at one end of the pack, and then I will use small boards simply for connecting the balancer plugs to the cases. I did a quickie proto board layout, and have a few of these showing up on Tuesday:

Each of these would be used with one of the sub-packs. this gives me the configuration flexibility, but it still means soldering a bunch of wires. I've been looking at maybe using headers on the boards, but I'm not having much luck finding ready-made flate cable assemblies that can handle the 2A I need for the individual cell chargers.

On the charging/balancing front, I now have the boards and parts required to make the cutoff circuit for a higher current "booster"/bulk supply:

I'll be putting this together this week. Bob has some surplus 17A supplies the phone companies use that we're going to try this with. I'll be posting more about this later this week. The board uses a modified version of the LVC circuit to detect when any one cell hits 3.7V. When that happens, the FET turns off, cutting off the boost supply. the individual cell chargers then just continue on, to finish of the charging/balancing process.

Anyway, more on all this later.

-- Gary

 

[Ypedal]

So have both bulk and single cell chargers plugged in and pushing power from the get go, then have the bulk side power off once the first cell hits full charge.. that right ?

 

[EMF]

<snip>

This would go at one end of the pack, and then I will use small boards simply for connecting the balancer plugs to the cases.

<snip>
-- Gary

Will cutting the balancing plugs for the cases off our Dewalt BMS be necessary, or did you find a compatible plug with wires attached, that fit the cases?

I think I saw some plugs over at the Mouser site from another post somewhere in this forum, but I am not 100% sure they fit.

http://www.mouser.com/search/refine.aspx?Ntt=538-22-03-5055

Plus, adding the terminals and wire to this plug looks to be tedious to say the least.

 

[bobmcree]

Will the Cycle Analyst from Justin not limit the Amp Hr draw? If we set it up properly.
Or
Are you going to make-up some of those simple BMS boards you designed for us to purchase?

the CycleAnalyst will cut off the throttle at a preset pack voltage. this does not prevent a single cell from dropping below the safe level. the only way to protect these cells from over-discharge is to sense the voltage of each cell. when you have a string of 10 cells the voltage will vary over a range of more than 10v so it is impossible to detect a single bad cell from the pack voltage.

i have been working with gary to help him get started with the bms boards and supporting him with ongoing improvements. he is the guy to buy them from.

 

[mn_aerorider1]

I am a new to your forum and this is my first posting. I have been following your discussions on Dewalt Packs and your LVC Warning Circuit and charger designs, for some time with great interest.

I have also built a 10s5p pack from Dewalt Packs - See my posts from the visforvoltage.org forum:

http://visforvoltage.org/forum-topic/batteries-and-chargers/578-a123-developer-packs

To build this pack, I bought a bunch of the 5 pin male connectors (from a Taiwanese wholesale source: http://php2.twinner.com.tw/customer/chienshern/pic/481.jpg ) They are a perfect match to the 5 pin connectors that come out of the Dewalt BMS module, that plug into the Dewalt 36V battery pack.

I still have a a large number left, that I'd like to recoup my shipping costs on. I'm selling them in sets of 20 for $10, and would be willing to negotiate a better price if someone wanted to buy a larger volume.

(Gary - I would be willing to trade some for 2 of your LVC boards!)

I have also been using a matching 5 pin right angle board mounted connector that I found on Mouser at:

URL

(I'm not sure that this URL will work as is...)
It fits perfectly with the 5 pin male connectors I've purchased, and the 5 pin male connector that comes out of the Dewalt BMS module.

I have not used the straight in connector that EMF pointed out, but according to Mouser, it should also be a match.

The only downside, as EMF has pointed out, is that you have to crimp the wires yourself.

Best Regards,

Brian

 

[GGoodrum]

So have both bulk and single cell chargers plugged in and pushing power from the get go, then have the bulk side power off once the first cell hits full charge.. that right ?

Thats it. The idea is that until the cells hit the cutoff they will be in the constant current (CC) mode, and the bulk charger simply adds more current. Once one cell hits the cutoff, it is assumed that the rest aren't far behind, so the bulk supply can be shut off.

 

[GGoodrum]

Will cutting the balancing plugs for the cases off our Dewalt BMS be necessary, or did you find a compatible plug with wires attached, that fit the cases?

I think I saw some plugs over at the Mouser site from another post somewhere in this forum, but I am not 100% sure they fit.

http://www.mouser.com/search/refine.aspx?Ntt=538-22-03-5055

Plus, adding the terminals and wire to this plug looks to be tedious to say the least.

No, those won't work. The pitch needs to be .100", which is 2.54mm. These are 2.5mm. The DeWalt plugs are rounded on two of the corners.

There are some plugs that can be made to work, but then you still have to add wires. It is much easier to simply cut the plugs off the DeWalt units, and solder them to a board.

-- Gary