ranger LifePo4
LifePo4 - why?
from a lot of the sites there is a great lot of reasons to go to lifepo4 batteries ....
besides tha fact they are the most ecological battery made to right now ...................
below is a list of the reasons that should be thought about ...
 
Safe technology?—?will not catch fire or explode with overcharge
Over 2000 discharge cycles life compared to typically around 300 for lead acid
Double the usable capacity of similar amp hour lead acid batteries
 
Virtually flat discharge curve means maximum power available until fully discharged (no “voltage sag” as with lead acid batteries)
High discharge rate capability, 10C continuous, 20C pulse discharge
Unlike lead acid batteries, can be left in a partially discharged state for extended periods without causing permanent damage
Extremely low self discharge rate (unlike lead acid which will go flat quite quickly if left sitting for long periods)
Does not suffer from “thermal runaway”
Can be used safely in high ambient temperatures of up to 60C without any degradation in performance
Maintenance free for the life of the battery
Can be operated in any orientation
Does not contain any toxic heavy metals such as lead, cadmium, nor any corrosive acids or alkalies thus making LiFePO4 batteries the most environmentally friendly battery chemistry available
LiFePO4 cells are of solid construction?—?there are no fragile/brittle plates made of lead which can be prone to failure over time as a result of vibration
 
One of the number one reasons to go to these batteries if we can get chargers that can do this !
 
Can be safely rapidly recharged?—?when fully discharged can be brought to a state of over 90% fully charged in 15 minutes
LifePo4 battery install
OK, Maybe not 100 miles to the charge but it sure gets our attention as a ranger ev driver when someone says this about any battery !!  I have read it many times but so far the most I have seen in miles per charge is the NIMH batteries at approx. 70 miles to the charge ,  50 to 60 is the normal for a ranger ev .......  according to the manufacturers you should get 80% more miles per charge then lead and 20% more mileage then the NIMH with the Lifepo4's ...........
 
so I will be realistic for now and say with the same size density of a cell they should go 84 miles to the charge ...................
 
We have heard a lot about them , they are going to be in a lot of the coming electric vehicles and now we will actually get a pack of them to test in a Ranger EV .... a friend has purchased a set of 100 cells @ 100AH rating to install in his Ranger ev ....
  A regular Lead Acid ranger batteries are good for approx.  7/10's (seven tenthths) of a mile per
amp Hour ... which in a full sized 5400 lb vehicle is actually pretty good ....... this can give up to 70 miles to a charge on a good day in Optimum conditions ...............
Mostly though we are looking at approx. 5 tenths of a mile per amp hour due to the heavy weight and the fact the best part of the battery will go away in a matter of 3 to 4 month and the ranger ev will settle in to approx. 40 to 50 miles per charge from then on until they make their next drop ...
 
  The Phosphate based LifePo4 battery is said to be able to expend a full mile to even 1.25 miles to the amp due to the fact the whole pack is only going to weight approx. 850 lbs ...
that means just in weight alone we will lose approx. 1200 lbs of weight ....................
so with a possible 1 mile per amp hour and the gain of power due to the vehicle only weighing 4,000 lbs instead of 5400 lbs it seems possible on paper to exceed 100 miles to the charge regularly ............ again we have never seen this so realistic life says 80+ miles on good days ..
 
  I guess we will see ... I am starting to set up the vehicle in preparations for the coming cells and I will post pics as we go along .........
 
Before Even starting the removal process for the pack I have found it is best to update the BCM from Lead acid to NIMH while it is still in running and good shape as the Flash update is very picky and if you make a mistake it will make the BCM useless and you will have to find a new one to update ............ so I went ahead and updated the BCM from Lead acid to NIMH and checked it and it took the update and it is ready for NIMH wiring and fans and cables ...................
 
  Welcome and wish us good luck, this could be a great breakthrough for extending the life of these great vehicles !!
Here we are, to spare the regulars I jacked up the ranger and removed the battery coffin (pack) and pulled out all the old batteries ............................
Time now to pull out the Old wiring a cables as we will not be using them, instead we are going to be using NIMH wiring and cables ...........................
I have to pull the old fan out as again we will not be using the old Lead acid stuff as we need to update to the NIMH 2 fan system ........................
And now after 1/2 a days work we have everything out and will now start putting it back together with the new NIMH parts to get it all ready for the LifePo4 battery cells ................
Today I have to add a vent for the NIMH fan so I wanted to offset the new fan cases to the side a little to allow to take the drivers side connection out of the case without having to undo the case
so I added this flow through vent it has little flaps so that when air is blowing out they life but they close so no rain , water, snow etc. can get inside ...
on the other side inside the box, I used the original recirculation NIMH fans for both the front flow through fan and the recirculation fan, that way they are interchangeable, the original systems used a small fan in the front and a large one in the middle makes more sense to be able to just look for one fan instead of two different ones ................. so I used regular old electrical boxes that were the perfect size , my dad made the mounts inside the box and installed the fans in them so I just had to bolt them to the battery case .................................................
same fan as the recirculation fan, bolt it to the case and you have 2 identical fans that were all original NIMH parts... we built our own cases as we could put slits in the bottom of one for recirculation air to be moved around at a higher speed then original and the flow through we just drill a hole in the back for the vent air and less then 2 hours work to get this part done ...
add the lids and get ready to add the wiring ......................................
OK so as not to bore anybody any more then necessary ... the wiring is not changed from the NIMH number 1 sense lead goes to the positive of the number 1 battery .. #2 goes to #2 etc.
etc.   plug in the fans ,  the only change I made in the wiring was I extended some sense leads to make it to the batteries that they belong hooked to and of course a lot of the high voltage connectors were cut off the sense leads and just rings crimped on and connected to the correct cell since 4 cells make up a battery .............................. 
  We went out and picked up some ready rod (all thread to some people) and my dad cut me some aluminum plates to sandwich the new cells in between and to squeeze them together into packs that we can handle .....................................
We lined the bottom of the pack with the original plastic inserts as it keeps the bottom set of batteries up off of the bottom and forces the air from the high flow fans we installed to be pushed under the pack and out the sides and the ends causing a great air flow all around the pack and then the air is of course pulled in the back of the pack and pushed out the front of the pack with the flow through fan .......
We finally get to do the fun part ... we take the Lifepo4 cells and group them into the amount of batteries we want to place into sections of the pack , of course we are looking to the future trying to see and build these so we could take them out in sections if we ever need to replace a cell that goes bad ............. we can build all different sizes to play with so we can decide which sizes are going to be the best ... a little time consuming but the end products end up a lot easier to handle then single sets of 4 bundled together ............................
OK after hours of assembling packs and making enough runs in my electric ranger to home depot and back getting parts we have finally assembled the batteries and we are now going to set them in the pack and wire them up for a preliminary test under the ranger ev ..................
all right now all the wiring is hooked up and the batteries are in the pack , we attached the BCM and IOM assy and the contactor box assy and rolled the pack under the ranger , I hooked up the pack with some extension cables and reset everything and with a few quirks and resets of the pack it pulled itself to Life .............  I will now cycle the pack a few times and using the NIMH algorithm for charging the pack I will monitor it really close to make sure the system does not over charge the pack at any time .....................  once that is done I will roll the pack back out and start moving some of the cells around and tape and put together the wiring for its final places and anchor everything in place before placing the top on the pack .................
I will guess another 2 days and I will be ready to do the final test but right now it is running up on jack stands so 80% of the work to install these is done !!!
Testing Phase
I am now into the testing phase and will fully test everything before starting to do the final assembly of the batteries and wiring ............................
I will post the readings I get from the charger next as that is the first testing phase , charging of the pack is very important , you can not allow the discharge of the cells to fall below their given limits and you can not use a charger that will allow over charging of the cells , either one will ruin the batteries .........
   The Lead Acid Algorithm can not be used, I have monitored a lot of lead acid packs and the charging algorithm in the BCM will over charge the cells every time you charge it ............
I have seen the charger go up to as high as 420 volts while charging, the maximum for these cells in a 100 cell pack is 380 volts .... over that and you are taking the chance of damaging the pack and that would be throwing away thousands of dollars ...........................
1st charge with On Board Original Charger
Here is so far the first charge of the Lifepo4 cells ........
This is with the On board charger Original and the NIMH algorithm ........
Begin time     Bat_SOC       Cus_soc  Charging Amps      Pack voltage
11:30               41%                  34%               9.91                       334
noon                48%                  42%              14.89                      337
12:45               57%                  53%              14.67                      340
1:15                 68%                  64%               14.52                     344
2:15                 82%                  80%               14.03                     349
3:10                 93%                  92%                 2.92                      340
3:30                 94%                  93%                 2.92                      343
4:15                 99.99%            99.99%           2.92                      364
4:30                 99.99%            99.99%           2.92                      373
4:40 - full shutdown stopped charging .......................
All right this is where everything went south , we got all done and then after the testing I realized that with the way the cells were setting on top the lid still was not going to go on the pack correctly ....  time to take it apart and start over ... remove all the plastic inserts as the pack is way too tall ......  place in all thread and the end plates, the all thread will hold up the batteries 1/2 inch off of the bottom and we cut slots in the end plates to allow the air to flow under the pack  ...
so we are going to set in the batteries again and redo the connectors to tighten the pack together ...
and side view of the rods and end plates ready for the batteries
I put all the two rows of 30 cells in the bottow to make a full 60 cells used up very quickly ..
when you have a 100 cells to put in you have to use all the space you can find to its optimum use .. added the tightener straps and tightened everything up snug ...............
I finally decided on the setting of the batteries in the back area to get the clearance for the lid that I needed ................
moved around the front section until I finally had the clearance to put in the IOM assy. and the BCM assy. where the cables would actually reach them ...  a little bit of work but it finally fell into place ...............................  since everything was ready I went ahead and wired it all into place added all the needed shims and finished up the front section ...................
 
then I went ahead and finished up the back section , added the contactor box assy... wired everything into place ........................
 
I rolled the pack under the ranger plugged it in for final testing and had some problems with the temp sensors , I kept getting a bcm_op 80 whick is the battery pack too cold for proper operation it is right at freezing here so if that is going to be a problem in cold areas since these do not seem to generate much heat I customized some connectors and installed some 5K ohm thermisters I had laying around which raised the temp by 7 degrees celsius for the BCM and it became a lot happier and everything was a go for it ............ I installed the lid and put it back into the ranger for some more final testing that needs to be done while driving ............
 
Pack is reinstalled and now it is time to charge it up and go for a drive ..............
It is now all charged up and time to make a run ..............
 
Final Testing
The Ranger has been fully tested with the NGS tester and I took it for a quick 40 mile run to make sure that everything is working well and I really could tell the ranger ev was a lot lighter and it seemed to have a lot better pickup and go ................
 
  I will try and do another run before it is picked up to go to its owner as I am running out of time to get it done before then ... we have a snow storm coming in and it has been right at freezing here for two days so it has been a good time to test the vehicle as lead acid rangers right now are down to 25 to 30 miles to the charge from the cold while these are not suppose to be affected by the cold as much ...........
 
 
Testing by Owner
I have now done my part , I have updated the ranger ev from a lead acid ranger ev to a NIMH pure 12 volt system fans, wiring, IOM and BCM assy ..........  it now has the best protection that the Ranger ev can give it , a very well engineered battery control module and Independent Observer Module to take care of the 4 cell battery module system .................
 
   I can not tell you how good the battery cells are , I am sure it will take 10 to 25 discharge and charges to bring the cells to full capacity ...  that of course is going to be the owners job ...
 
  Hopefully he will keep us all informed as to the miles per charge and the life of these cells ..
 
  I know there are a lot of different Lifepo4 cells out there and I was very impressed to find out that the battery was actually invented right here in the United States
 
Thank you Prof. John Goodenough of UTA who invented LiFePO4 (at MIT).
 
  very impressive and again the United States had the technology and has let that power slip to a quick moving China and Korea markets who now build them and are shipping them back over to sell to us !!
 
  Either way the decision is now which ones are the best and which ones are boat anchors ..
  I have no problem testing a few of them but I only own 2 honda watercraft so I really only need two anchors so any more then that and it is a waste ..........
 
   Thanks and let me know as always what you think !!