My official Prius Plus mods thread.

<div class='quotetop'>QUOTE(mrbigh @ Sep 25 2007, 06:49 PM) [snapback]517661[/snapback]</div>

Thanks for the tip, I'll look into those!

Rob

 

<div class='quotetop'>QUOTE(Rob Smith @ Sep 26 2007, 05:39 PM) [snapback]518187[/snapback]</div>

Is this the one you're looking at?
http://www.panasonic.com/industrial/batter..._LC-RD1217P.pdf

For Panasonic LC-RD1217P I get Np = 1.21, Cp = 16.4Ah, resulting in 6.8 minutes to 100% discharge at 60A. Weight 287.6 lbs, cost $1035 at digikey price.

For BB EVP20-12 I get Np = 1.146, Cp = 20, resulting in 11 minutes to 100% discharge at 60A. Weight 286.6 lbs, cost $800.

So, it seems to me that for the same weight the BBs give 60% longer run time at load, for less money. They will also do a little better than shown, as their internal resistance is lower which is not accounted for in this calc (my big spreadsheet is at home).

Not trying to be a wise guy, just want to understand why you like them.

Rob

 

<div class='quotetop'>QUOTE(Rob Smith @ Sep 26 2007, 06:16 PM) [snapback]518207[/snapback]</div>

You might want to double check on the $800 if that wasn't recent. Lead prices have more than tripled this year and most AGM battery manufactures have increased prices around 40% just in the last 2 months. I believe that typically BB and Panasonic batteries are closely priced.

You might also look at the Universal 22ah battery: UB12220. They are the same physical size (although the terminals stick up over the top about 1/8") and I think just slightly heavier. I did a PHEV conversion using those batteries in my parent's car and they are seeing a 16 mile EV range. No idea how they will hold up as far as number of cycles, but they seem to be able to do about 4kWh / cycle throughput.

Chris

 

<div class='quotetop'>QUOTE(Rob Smith @ Sep 26 2007, 07:16 PM) [snapback]518207[/snapback]</div>

I agree with Chris also, prices went sky rocket lately. Digikey doesn't have the best prices around in this type of batteries, google for master distributors but be aware of S/H, these are heavy.

In your replay, the two type of batteries are not equal in Amp capacity, the Panasonic you choose is 17Ah and the BB is 20Ah. As a note, I'm using 20 Panasonic 28Ah

 

<div class='quotetop'>QUOTE(mrbigh @ Sep 26 2007, 07:36 PM) [snapback]518241[/snapback]</div>

True, but they are the same size and weight. If the BB battery can get 20 Ah in the same volume and weight that the Panasonic gets 17Ah out of, I'd call that a fair advantage to the BB. Its advantage extends further due to its better Np and lower Ri. At ~60A the BB still has 10.9Ah while the Panasonic is down to 6.72Ah. The 28Ah version appears to be a much better unit, with a Np of 1.106 compared to the 17 Ah's of 1.215. That should make the 28Ah version perform much better, but its over weight for what I'm looking at currently.

Ok, you got me there. The place where I believe everyone was buying $40 BB EVP20-12's seems to have dried up, they no longer show them at all. (http://shop.electricross.ihoststudio.com/). Agreed also on the web pricing, just using it as a preliminary data point. Mostly trying to find the best batteries first, then try to find which ones of those I can find the best deal on. I'm probably going to have to give some preference to the Gruber GPS batteries even though they're probably not the best, but they are local. Still waiting to get specs on the correctly sized ones from the manufacturer.

Good call, I had missed that one I had only seen the UB12180 which is nothing special and the UB12260 which is too heavy and still not great. The UB12220 has a much better Np and still reasonable weight.

Here are my best performers so far, based on the previously mentioned calc method. This is probably sort of a worse case condition, a constant ~60A (really constant 14.4kW) discharge. So far I'm only really looking at batteries that get me into a 250-300 lb pack.

Battery-------------kWheff--------Wh/lb------kWh/cuft
BB EVP20-12--------2.50----------8.71---------1.55
CSB GP12170-------2.52----------10.4---------1.55
UB12220 ------------3.06----------11.7---------1.87
MK ES20-12C -------2.63----------9.04---------1.63
Yuasa NPX-80-------2.81----------9.70---------1.74
Tempest TH1295W -2.79----------9.29---------1.72
Genesis G16EP------2.55----------9.45---------1.55
Pan LC-X1228P------4.32----------8.86---------1.64 -- *486.8 lbs

and a few of the worst.....

Battery-------------kWheff--------Wh/lb------kWh/cuft
Odyssey PC680-----1.99----------6.46---------1.14
UB12180 ------------1.67----------7.04---------1.03
UB12260 ------------2.63----------7.29---------1.00 -- *361.6 lbs
CSB EVX 12170-----1.31----------5.23---------0.80
Pan LC-RD1217P----1.52----------5.29---------0.94
Pan LC-X12220P----1.93----------6.66---------1.19
PS12180-------------1.80----------7.14---------1.10
Rhino SLA 17-12----1.68----------6.32---------1.04

I guess the next step is to start paring down the good list based on price, life expectancy, and internal resistance (to minimize sag under load).

Rob

<NOTE> The purpose of this calculation is to have a fair comparison of the performance of these batteries under load. In reality the voltage will erode as the battery is discharged, accelerating the discharge. Its also pretty unrealistic that you would run the pack from full to empty all in one go. There will probably be periods of light loading, where all the batteries will perform better, and rest/regen periods where the battery voltage will recover somewhat. This complicates the process of trying to turn this calculation into an absolute representation of range. I do believe however that the relative trends will hold though. A battery that does better in this worst case simulated test (assuming the numbers its based on are good) should result in longer range in the real world. At least, thats the theory

 

CHEAP

Thats one great looking unit. As you know the Altima and the Camry hybrids are essentially identical. (some minor differences in the ICE's. I bet that your Prius system would work in a Camry ? What do you think ? If so I could maybe streatch the application to the Altima.

If these are possible I am very interested in buying one of your units for my Altima. Sure the range would be different but still a heck of a lot farther than I can EV it now. Comments.

PS I did know the plug system only recharged your added Pb batteries, Thats not what I wanted to do I wanted to recharge those little tiney OEM batteries.

 

<div class='quotetop'>QUOTE(Cheap! @ Oct 2 2007, 02:29 PM) [snapback]520449[/snapback]</div>

Very nice work! Those look great. I'm hoping to be able to come out to Austin to see or even help with the install, but I haven't sprung the idea on the SO yet as shes been out of town. I'd really like to see one of these done before I jump into mine. When that time comes I'll definitely be interested in buying some pre-made bits and pieces from you if they are going to be available.

Rob

 

<div class='quotetop'>QUOTE(Rob Smith @ Sep 25 2007, 05:26 AM) [snapback]517323[/snapback]</div>

Just curious, why the interest in this particular line? By my numbers they look inferior to the BB EVP, and even the CSB GP line in every sense except maybe cycle life. Better cycle life is obviously good, but higher price rubs a lot of that benefit out. Here's what I'm calculating and how, maybe I'm doing something wrong?

Rob
[/b][/quote]

Wow, I guess I haven't been checking here lately.

I don't have the calculations at the moment, but probably most of your calculations are right. The statement about cycle life vs. price is obviously a focus. The EVX line is supposed to be designed specifically for "efficient discharges in cyclical applications" according to CSB. And while both of us have done calculations, we don't have the "real-world" results. However, it seems that some of the generic batteries which were not designed for such applications may look OK at first calculations, but might not be able to meet those claims when put to the test. And the EVX line might not either, the true lifespan of a battery is so variable and the battery makers use their best numbers of course.

If you approach it saying I only have $X to spend, it may be better to get a cheaper battery that wouldn't be discharged as deeply as an expensive battery. However, if you try to maximize the bang for your buck you will probably be better off spending extra at the beginning and getting good batteries which will outlive the cheaper batteries.

 

Battery box question:

Is there a reason that everyone seems to be going with a full sealed type box? I would think an aluminum angle iron design with bracing and strapping across each battery set would provide similar mechanical strength in an accident, at substantial weight savings?

Possible concerns I can think of are:

1. Battery rupture in an accident.
2. Battery venting of hydrogen gas.

For 1, I was under the impression that AGMs had virtually no leakage when broken. The acid is absorbed into a matting, and not floating around as in a wet cell, or gel cell.

For 2, Am I right in thinking that hydrogen venting of VRLA batteries occurs only during severe over charging? Is there any way this can happen when you are not parked and plugged in? I am assuming when charging its wise to keep the vehicle partially open and ventilated, as the BEV conversion folks usually do? If the goal is to try and seal the battery compartment, would it not be easier to try and create some sort of gasket seal around the load floor, rather than creating a solid metal box?

Rob

 

I'm impressed, WOW!!!!

 

Cheap,

My name is Clayton, and I am a mechanical engineering student at the University of Texas at Austin, I am currently converting my uncle's 04 Prius to a PHEV.

So far I have purchased, the EV button/kit, CAN-View V4+, Lilliput screen GL701-NPCT. I am in the process of installing these items. This thread has been a wonderful source of how-to information -- Thank you for all your documentation efforts!

I plan on creating a website documenting my conversion process. I am taking picture of my screen install right now -- I took the dremel to map holder -- so my process is no longer completely reversible.

I am considering going with the PiPrius i.e (using the Manzanita Micro charger) method versus the Prius+ method that you have chosen. I would also like to use a different battery chemistry than PbA -- was thinking of purchasing 3 used stock NiMH and stringing the modules together the way Norm, from hybrid-interfaces, did.

I would like to hear your thought on PiPrius vs. Prius+ methods, and how easy would it be to do the Prius+ methods with a chemistry other than PbA?

I will definitely see you at the Maker fair!

-Clayton

 

<div class='quotetop'>QUOTE(claytonsuch @ Oct 5 2007, 07:42 PM) [snapback]522050[/snapback]</div>

Wow. Nice first post.

 

<div class='quotetop'>QUOTE(Cheap! @ Oct 5 2007, 09:55 PM) [snapback]522097[/snapback]</div>

Hey Cheap!,

That was one kool project! I just finished reading almost all of the posting regarding your PHEV. You got me thinking of doing one myself. I got some questions:

1. Can I just use a 216v (rated at 2.1kw--4.2kw at 15--30 amps) battery? I just want to parallel this to the OEM battery. Shouldn't this help?

2. Do I really need all that CAN-view stuff? I have an 05 Prius. Wouldn't the OEM computer just pick up the voltage, combine it, use it, and then broadcast the level on the MFD?

3. Did you ever consider--or has anyone consider--using the batteries from the a123system company. They claim to have some advance batteries--and they cost a pretty penny!

Any feedback from anyone would be great! I am not an expert in electronics, but I was a generator techician in the Army--I am use to playing with high voltage (400KW). I plan to use the a123system's batteries, without paying 12K for it (Hymotion's price). Thanks everyone!

 

<div class='quotetop'>QUOTE(kammssss @ Nov 21 2007, 05:50 PM) [snapback]542638[/snapback]</div>

If you find a source for the A123 Lion's at discount price, meaning <$5,000.00 and available with out being an eternity, please share the information with all of us.

 

<div class='quotetop'>QUOTE(kammssss @ Nov 21 2007, 04:50 PM) [snapback]542638[/snapback]</div>

Hybrids-Plus is using A123 batteries also:
http://hybrids-plus.com/
Great pictures of the batteries and install here:
http://hybrids-plus.com/pmwiki/index.php?n=Ext.Conversion1

 

<div class='quotetop'>QUOTE(mrbigh @ Nov 21 2007, 03:53 PM) [snapback]542675[/snapback]</div>

Hey boss, so what do you think of my first and second question?

1. Can I just use a 216v (rated at 2.1kw--4.2kw at 15--30 amps) battery? I just want to parallel this to the OEM battery. Shouldn't this help?

2. Do I really need all that CAN-view stuff? I have an 05 Prius. Wouldn't the OEM computer just pick up the voltage, combine it, use it, and then broadcast the level on the MFD?

Thanks in advance!