New LiFeBatt-based pack...

[GGoodrum]

Thought I'd post some pics of my new custom G10-based 16-cell 48V/10Ah pack, which uses LiFeBatt 10Ah cells:

What I did was simply extend out the sideplates, in each direction, and add top, bottom, rear and front black G10 panels. The cells ar inter-connected using crimped ring terminals and 10-gauge lengths of wire. These are sandwiched between two nuts. The side panels are then placed over these, and held in place with nylon acorn nuts, which also provide insulation for the end of the cell studs. There is also a handle on the front.

I'm going to do two versions of this pack, one with the LVC board, and one with the full BMS that Bob and I have been developing. The LVC has an 18-pin coonector which can be used to connect to external balancers, individual cell chargers, etc.

I'm also doing 12-cell 36V packs like these as wel. I'll post some pics f these later.

-- Gary

 

[recumbent]

8) Nice build Gary, looks like it will fit sideways (15") inside my panniers, I'll take one 48volt please, Oh... right, How much would these cost approx.

What is the price difference between a 48 volt "LVC" or "BMS".
The BMS will keep our lifebatts balanced, right? And also includes the LVC, right?
I get confused with all this new stuff, but want a proper, no fuss set-up

Will my "red" and "black" Anderson power polls on my C-lyte controler automaticaly fit properly? or do i have to check polarity with my meter?

Some of us like to tinker but not fully understand electronics :?

 

[GGoodrum]

You are right, the BMS includes two primary functions, low-voltage protection, and charge management/balancing. Originally, we had these functions split, into the LVC board, which handles the monitoring of each cell and turns off two big FETs that the main pack negative lead is connected through; and a Charger Management System, or CMS, which uses shunt-type voltage regulators on each channel that allows each cell to do the final CV portion of the charge cycle independently.

I have had a number of requests to do packs with the LVC board, instead of the BMS, because they intend to use indiidual cell chargers, with the 2A VoltPhreaks unit, or using multiple 10A 3-5V supplies. Others plan to charge using standard bulk CC/CV chargers and then occasionally use RC-styled balancers to externally balance the pack. Finally, I have also had requests to still do the external CMS unit, because these people will have multiple packs and they want to only have one charger and one CMS to share between the packs. I actually fall into the latter category as well. I have two 12-cell packs on my wife's bike, two new 12-cell packs on my Mariner folding bike and the 16-cell pack shown in the pics above is going on my Port Runner folding bike. I'm equiping all these packs with LVC boards, like the one shown below, and then doing a single CMS board, which will go in an extruded aluminum case. I'll use this CMS unit with 36V and 48V Soneil and Zivan chargers, on all the packs. Eventually, I will probably do a 2nd CMS unit, so that I can charge two 12-cell packs at a time, but initially, I'll just use the one.

This board is now mounted inside the pack and plugged into to another plug that has wires going to all the cell junctions. The front cover has a dummy plug attached to it, so that it plugs into the connector on the board. You can pop this cover off in order to get access to the multipin connector on the board. The CMS will have a cable coming from it with a matching multipin plug.

Anyway, I will try and offer pack versions to suit everybody's stated needs. I will begin selling LVC-equipped 12-cell 36V/10Ah and 16-cell 48V/10Ah packs today, and will start selling versions of both with the BMS, when it is ready. The 12-cell LVC pack will be $599 and the 16-cell will be $749. The 12-cell BMS version will be $685 and the 16-cell with BMS will be $875.

When they are ready, assembled and tested BMS units, will go for $135, for the 12-cell version, and $159 for the 16-cell unit. Both will come with heatsinks, a harness with a mulitpin connector and a separate set of wires with a matching multipin plug for connection to the cell junctions in the pack. They will also come with output leads that either terminate in a Deans connector, or standard PowerPole red/black connectors.

A fully assembled and tested CMS unit will go for $145. The board will be installed in a black anodized extruded aluminum box, which ends up supplementing the board-mounted heat sinks so that the current for the final phase can be cranked up higher than possible with the pack mounted BMS boards. The CMS unit will have an input connector for plugging in a standard CC/CV charger, like the Soneil 3610 and 4808 SRF-type chargers, and then an output cable, with a mulitpin plug, that goes into the matching recptacle-type connector on the pack-mounted LVC board.

Anyway, I will put up the LVC-based packs on my site today. I'll be final testing the CMS unit this weekend and will then make those available starting Monday. Bob should get new BMS boards today, so he will hopefully be doing the final verification tests on the BMS boards over the next few days as well. Once he's happy with the performance, I'll put them up on the site, and I'll make BMS-equipped 12-cell and 16-cell packs available.

I will also make the Soneil 3610 and 4808 4-4.5A chargers available next week as well. The 3610 SRF will be $135 and the 4808 SRF will cost $149.

-- Gary

 

[lawsonuw]

VERY nice looking battery there! Makes me wish I was ready to put a Lithium battery on my bike.

Marty

 

[Link]

That's a fine looking pack you've got there.

Care to tell us dimensions? Pics with size references (coke can, ruler, equivalent SLA pack ) would be nice.

 

[Jozzer]

Thats a very nice price on a nice pack Gary, well done, its clear who's side you are on

 

[GGoodrum]

That's a fine looking pack you've got there.

Care to tell us dimensions? Pics with size references (coke can, ruler, equivalent SLA pack ) would be nice.

The pack above is 3-3/4" x 6-3/8 x 16" (15" without the handle...). I haven't weighed it yet, but I'm guessing it is right at 15 pounds, or a bit under.

 

[GGoodrum]

Thats a very nice price on a nice pack Gary, well done, its clear who's side you are on

Yep, I'm not making squat on these, and we are pretty much giving away our labor, but my hope is that the cell prices will eventually come down, and then Bob and I can make a ducat , or two.

-- Gary

 

[recumbent]

The pack above is 3-3/4" x 6-3/8 x 16" (15" without the handle... I'm guessing it is 15 pounds, or a bit under.

My panniers are 17" long at the widest point then tapers down at bottom to 15".

I'll still be able to lay it down with a foamy underlay... Phew that was close.

Thanks Gary for building these, heavy duty power supply modules for us.

I'll place my 48V order next week when you have it up and completed.

 

[CGameProgrammer]

Great work on the pack, but in order to sell them at any real volume, you also need a charging solution that works out-of-the-box with the pack. They should really be sold bundled together, in fact - as an option, I mean.

 

[GGoodrum]

Great work on the pack, but in order to sell them at any real volume, you also need a charging solution that works out-of-the-box with the pack. They should really be sold bundled together, in fact - as an option, I mean.

Actually, there will be a choice of chargers, a SRF series 4-4.5A Soneil, or a 10A+ "Speedy" charger from LiFeBatt. The latter are in the final stages of getting UL-approval, and should be available this month. The Soneils will be available with the packs, which should be listed on my site by the end of the week.

-- Gary

 

[GGoodrum]

Also, the "CMS" unit will be available at the same time as the packs with LVC boards. This is the reason for the delay of getting the LVC-equipped packs up and available. I've been testing the CMS for the last couple of days. I hope to finish that effort up today, and I'll post some pics later.

 

[disadvantage]

Duct tape battery packs are the new SLA.

I think people buying duct tape packs today will be buying LifeBatt next biking season.

I hope Gary is ready for the rush, and makes some money.

 

[albie]

that's if the prices become more affordable.

 

[GGoodrum]

As many here know, LiFeBatt won't supply us with cells anymore, due to their recent agreement with Phostech, which prohibits LifFeBatt from selling into the ebike/scooter market, which is the "exclusive" territory of PHET, another Taiwanese battery maker. We are lookng into doing packs based on PHET's 11Ah cell, which is the same diameter as the the LiFeBatt 10Ah cell, but a bit longer (155mm vs 138mm...), but this will take months, I'm guessing, before we will be able to actually offer packs. the published specs on the PHET cell are pretty weak, compared to the LiFeBatts, but that might be because the data is old. I just don't know yet.

In any case, I have decided to sell my one last 48V/10Ah LiFeBatt pack, along with a Soneil 4808SRF charger and a pair of TP-210V auto-balancers, as a one-time package deal. You can check it out here: http://endless-sphere.com/forums/viewtopic.php?f=9&t=4115.

Since these cells are "pre-agreement", they still carry the two-year warranty.

-- Gary

 

[Malcolm]

It's a shame to hear you can't get the loose cells anymore after all the work you've invested Gary. Do you know anything about the cells for sale on the Cyclone Taiwan site? They look very similar, but no specs are given.

 

[GGoodrum]

It's a shame to hear you can't get the loose cells anymore after all the work you've invested Gary. Do you know anything about the cells for sale on the Cyclone Taiwan site? They look very similar, but no specs are given.

Yeah, it sucks, but what are you going to do...

The cyclone cells look like they are the PHET cells, which are supposedly 40 x 155mm, vs 40 x 138mm for the LiFeBatts. The latter has orange and black ends, and the ones in the Cyclone pic are white. I too know nothing about these cells yet, but I'm guessing if they are using "approved" Phostech powder, the specs ought to at least be similar. They do sell the 36V/10Ah version with a 10A charger, so that says they can at least be charged at a 1C rate. That tells me the cells are probably good for at least 4-5C. That's vs. 10-15C for the LiFeBatts, and 30/50C for a123 cells.

-- Gary

 

[GGoodrum]

I have reduced the price on my LiFeBatt-based 48V/10Ah pack/charger/balancers combo deal to $850. This is a great deal, and is definitely below my cost. The charger alone is $160, most places, and the auto-balancers are normally at least $95 each.

If someone already has a charger setup, I'll also let the pack-only go for $700. Again, this is a great bargin, and well below my costs for this pack.

-- Gary

 

[Jay64]

Gary, I just bought one of these packs off David (ort5)
http://endless-sphere.com/forums/viewtopic.php?f=9&t=4383
You had told me before that the A123s can push out 200 amps. I know they have a 30C rating, while these Lifebatts have a 20C rating, if I am not mistaken. How many amps can this pack push out? I'm planning on getting an alltrax AXE 7234 controller to use with a Etek RT motor. How fast will the Soneil 48V/3A 4808SRF charger charge this pack back up?

 

[GGoodrum]

The continuous rating for the LiFeBatt cells is 10-15C continuous, and up to 20C for short bursts. That translates to 100-150A continuous and up to 200A bursts.

The Soneil charger maxes out at 4A, so if the 10Ah pack is completely depleted, it will take about 2-1/2 to 3 hours to fully recharge it.

-- Gary

 

[Jay64]

Actually, sounds like a good question to me, I'm interested in the answer too.

 

[GGoodrum]

Hi Gary,

It's may be a stupid question but I like to have your advice on this one. Is better to use a 48 Volt 30 Ah A123 pack or 48 Volt 60 Ah Headway Or your new cells with my Alltrax 4834 dirt bike set up. The goal of this is like to have kick take off and long trail riding, so what do you suggest and why?

Thank you and have a nice day!
Bruno

I think the Headway cells max out at about 5C, so 5 x 60 = 300A max load you can pull for a few seconds. The a123 cells can actually take up to about 50C for short bursts, so the max for a 13p/29.9Ah configuration is about 1500A. To do the equivalent of the 60Ah Headway configuration, an a123 pack needs only a about a 3p configuration.

However, it is not a good idea, in my opinion, to run cells close to the max "burst" rating on a frequent basis. The reason is that the voltage drops more, as you reach this point, and you lose efficiency. With weaker rated cells, this becomes even more pronounced. I think this can also have an adverse effect on longevity, but that is just my gut feeling. A good rule of thumb is to use the cell's max continuous rating as the limit for how much the system will ever draw. For the Headway cells, that is probably 3C, so if you have a 60Ah configuration, the max occasional burst current should not exceed 180A. LiFeBatt cells have a max continuous rating of around 10-12C, so for a 10Ah pack, the max burst current should probably not exceed 100-120A. With a123 cells, you really don't have to worry abut max currents, so you should simply size the configuration to match the durations you need.

-- Gary

 

[Jay64]

Gary, so you are suggesting that I set my controller to not pull more then 100-120 amps? So I should be able to run that continuosly until I need to re-charge and be in a 'safe' zone? Let's just say that I want to do some drag racing. Just to get out on a Wed. night, have some fun, and get people's attention for EVs. How many amps could I pull for say about 13 seconds? (1/8 mile)

 

[Jay64]

Gary, I want to try to get some connectors that can plug straight into the ones on this pack. What are they called, where can I find some?

 

[GGoodrum]

Gary, so you are suggesting that I set my controller to not pull more then 100-120 amps? So I should be able to run that continuosly until I need to re-charge and be in a 'safe' zone? Let's just say that I want to do some drag racing. Just to get out on a Wed. night, have some fun, and get people's attention for EVs. How many amps could I pull for say about 13 seconds? (1/8 mile)

Well, you could try 150A, and see how they do. If the voltage gets pulled down too much, the LVC circuits will kick in. If that happens, I'd adjust the current down. If the voltage drop is not too great, you might be able to go higher, I just don't know.