Todd Dore's LiFePO4 batteries

[ted.lowe]

Sweeeeeeeeeeeeeeeeeeeeet Todd!  i'm getting the urge to "go lithium" now :-)  My t-125 pack is 4 years old now and starting to tire, so i'm considering a change in chemistry.  Thanks for all the detailed information about your experiences!!

[robert.mcpheron]

My lead acid are approaching 2yrs old (sept) and I am also getting itchy my self. Keep posting updates when you have time.

tks mac

[todd.dore]

More updates -

Yesterday I went to a client meeting, then back home to charge.  Then to Lincoln Park for dinner and back.  Total miles = 90!  in one day!  Total energy = 29kWh. Good mileage!

Today I went to a doc appt in Hoffman Estates and back - total miles = 64.  Total energy = 17kWh.  Great mileage!

Total for 2 days = 154 miles.  A major record for any of my converted EVs.  Total energy = 46kWh.  Total efficiency = about 300Wh/mile.  Good stuff!

It was mostly highway driving.  I go 55-60mph.  The challenge is that if traffic is light, everyone else is going 70mph.  They pass me like I'm going backwards and give me dirty looks.  I previously didn't drive much on the hghwy with the EVs, so I'll have to get used to it.  Oh well - at least my fuel doesn't result in an oil spill!

More as time goes on -

[robert.mcpheron]

I'm guessing you are charging with 220v for this much driving, I read the chargers give the option either 110 or 220v depending on where you might be recharging. Whats the voltage of your sys, mine is 96v or 16  6 volt golf cart batts. The supplier talks about going over voltage due to size of basic unit (12v +/-) is your supplier Elite Power ?

[todd.dore]

Robert -

Yes, I have a 220V outlet in the garage.  My charger is a Manzanita Micro PFC-20.  So, I'm charging at Level II.  This charger is cabable of either 110V or 220V AC input.  It's pretty sweet.

[robert.mcpheron]

side question, my motor is exposed under car, I avoid driving in the rain. One time it did act strange...  Should I not drive in the rain

[todd.dore]

You need to get a belly pan that will shield the motor from moisture.  It's pretty easy to attach one - aluminum sheet metal cut to shape and bolted with 1/4" self-tap sheet metal screws to the frame will do the trick.

[todd.dore]

Today I drove 52.4 miles, over 2 trips.  Almost all highway driving, with an opportunity charge in between at home (even though it wasn't necessary).  Total energy = 16kWh.  Efficiency = 305Wh/mile.

So efficiency is ranging from about 290-350Wh/mile, and most runs are closer to 300Wh/mile.

With all the driving I'm doing, I should get to 1,000 miles soon.  I have between 600-700 miles on these batteries so far.

Tomorrow will be another early morning run to Hoffman Estates for family planning.  All highway and about 60 miles.  It's nice to be able to rely on this car!

[todd.dore]

More fun updates -

Yesterday, ran 64 miles, all hwy, and used 19kWh.  So pretty good efficiency again.

However, it was raining in the morning.  When we got back home, the car was soaking (outside).  I plugged in the charger and turned it on, and went to close the trunk, and got a nasty shock!  So, I turned off the charger, and unplugged the main breaker (Anderson connector) so the pack is totally isolated.  Turned the charger back on, and POP!  Something blew inside it.  Current continued to flow out - very odd.  So I turned off the charger to see what was wrong.

I disconnected the charger and opened it up - one of the 3 main capacitors blew like a cherry bomb!  I called Manzanita and spoke with Rich Rudman.  He mentioned that the capacitor quality wasn't that great with the older models (this charger is almost 8 years old).  So, I shipped it UPS today back to him, and he will replace the capacitors and send it back for a modest fee.  The good news is the capacitor replacements will be upgrades.

Rich is doing well - they just moved into a bigger shop/office, and he has a staff of 6 including a secretary.  They can crank chargers out within 2-3 weeks from the order.

I fortunately have a backup Zivan charger that was adjusted to 174V (top voltage), and this voltage which works well for my LiFePos.  I charged the pack up.  It takes more time (only 16 amps out of the Zivan vs. 20 amps from the Manzanita), but works ok.  It will be my backup until the Manzanita is back.  The BMS 'warning' system still seems to work ok.

The original isolation problem has to do  with the DC-DC converter.  It seems to have capacitors in there.  Anyway, not sure what can be done, but it does create some voltage leakage from the main pack because it is 'always on'.  I'll have to see if anything can be done about this.

That's all for today -

[todd.dore]

Yesterday I had my first and hopefully last panic about the LiFePo batteries.  Since the Manzanita is being repaired, I've been using the Zivan.  It was adjusted to 174V top-off, which was about where the Manzanita was.  I had manually watched it a couple times.  A number of regs went red (3.65V), but none triggered the alarm (3.8V).  There charger went into shutdown mode after CC/CV just fine.  So I drove to get our dinner (wife was still recuperating and I was in charge of 'cooking') and came back I knew I didn't have a full charge when I left, and after about 7 more miles, figured about a 2 hour total charge to top off the batts (the Zivan is about 20% slower than the Manzanita).

I went inside, ate dinner, and took a nap.  After a total of about 1 hr and 20 min, I went out to check on the charger.  As soon as I approached the garage I heard the dreaded sound - the alarm was going off!  I was on the phone with a friend and had to hang up ASAP.  I ran to the garage and threw open the door.  'I'll call you back Jesse - I have an emergency!" - and hung up right away.  I can't remember all the details but I think the Zivan was at the CV phase where you get the blinking red light (CC phase is solid red).  Almost every battery in the back box was showing red lights and the alarm was ringing all the way to China!  Oh C#%p!  What happened?

I immediately unplugged the charger in no time flat, before bothering to check the current output from it.  If it was blinking red, (which I cannot recall with 100% accuracy), it would be pumping out about 5 amps.  The next 10 mins. were a blur - like a bad car wreck.

Continued...

[todd.dore]

I think the alarm went off within 1-2 mins, but again I cannot be sure.  I got out a spot light and whipped out the meter to check where the batts were.  Frantically testing the voltage, the highest I saw was 3.85V.  Mind you, this was about 3 or 4 mins. after unplugging the Zivan.  I tested others - 3.7V, 3.6V, 3.8V, 3.75V, etc.  All of these were throwing red lights.  But, one by one, the red lights start disappearing, which I took as a good sign.  I felt the batteries - they were not warm (about room temp which was 80F).  The regs on the other hand have small ceramic heat sinks and some of them were very hot.  They were apparently disapating as much energy as possible.  I didn't even know the regs could do this.  Within 10 mins. or so (again, can't recall exactly), all the red lights were gone and the batts were settling down.

I removed the Zivan from the car and looked at the peak voltage setting switch - it was set on the next higher setting - about 194V!  This would give 4.08V per batt, if they were all perfectly balanced (which of course they are not).  Whoa!! How the heck did that happen?  No wonder the alarm set off.  I used a small screwdriver to dial it back down to 174V, which it did very easily - too easily!  So that was the culprit - when the charger was in the back of the car, it was bouncing around when I got dinner.  The peak voltage setting is a bit loose, and it must have jarred this to the next highest setting.  Cripe!  From now on NO CHARGERS IN THE CAR WHEN DRIVING!


Continued...

[todd.dore]

After things cooled down a bit I went into the house and told my wife.  She was worried and not happy about it.  If these batts go bad, I cannot replace them.

So I decided to take a short trip to see if everything still worked.  On the road near the house, I called a friend and asked what he thought.  He was mentioning that heat build up can kill the batts, so advised that I head back home and let things cool for the night, which I did - but not after putting about 6 mi. on the car.  No problems driving, and afterwards all batts were normal temp and a reasonable voltage (3.335V).

I called another FVEAA friend and asked what he thought about a warning system - ideally some way for me to hear the alarm if I'm in the house.  Suggestion - get a baby monitor and put it near the back battery box so you can watch them and hear the alarm!  Great idea!  He even offered to loan me a spare one that he had.

No charging that night - I was too paranoid!

Back in the house, time to do some research.  First the BMS - http://www.cleanpowerauto.com/MiniBMS.html  to the website I go and study the manual.  It's been updated in the short time since I originally installed it (about 1-1/2 months).  Since I had the Manzanita, I had concentrated on it's wiring to the BMS.  But there's a nice YouTube video of Dimitri (owner) showing how the BMS works with a Zivan.

Continued...

[todd.dore]

So - watching the video and looking at the diagrams - What's this?? There is a way to hook up a relay to turn off the Zivan when any 1 cell hits 3.8V?  This is the safety feature I didn't have!  I only had the top off charger voltage, and that failed because it was jarred to a higher value.  Silly me!

I spoke with Dimitri today and ordered the solid state AC relay (he sells them).  2 day shipped UPS from FL - more in shipping than the cost of the relay!  But no charging until that baby is here and installed - which should be late Saturday.

His advice was that if the batts were damaged, heat doesn't do it - overcharging causes swelling.  I need to look for gaps between the batteries.  If they swelled, then they are damaged and have lost capacity.

So back home tonight I inspect - no noticable gaps except for 2 junctions (max. total 4 batts) - but there's nothing blatantly obvious - this could have been there before.  Per another friend's advice, the only way to know for sure is to drive the car and charge it up - over time, to make sure it keeps and holds a charge and can perform.

As noted above, I won't charge until Saturday, but I decided to drive around to see if the batts hold a charge.  Tonight was ideal driving weather.

Continued...

[todd.dore]

I stayed off the highway - too risky for this test.  I drove until I had 38 miles (6 were from last night).  Dropped into my garage and tested the batts - no red lights!  All within 0.012V of each other - 3.3301V-3.3313V.  Not bad!  So off to more testing I did.  Another 18 miles, easy driving (no big acceleration).  I'm amazed at how little energy is used to keep the car going at 40mph - sometimes < 50 amps!

So, total distance = 56 miles.  Back home, checked the batts again, and they were all at 3.29V - all within 0.005V of each other!  How's that for balanced?

Early conclusion - I didn't seem to damage the batts.  Thanks be to the Lord on High!

Of course, time will tell - I need to charge the batts again (this time with safety shut off relay), and charge and discharge the car multiple times.  Only over a long period will I be able to tell if any damage has been done.

So lesson learned - make absolutely sure about the BMS operation and safety shut-offs of the charger before charging!  These batts don't forgive (I've been told).

Continued..

[todd.dore]

I got the call from Manzanita today - repair bill was about $500.  Yikes!  New capacitors (ultra caps) and a new control board - Rich wasn't happy with the old board (this charger is about 8 years old!).  So, I should get it back in about a week.

I'll keep everyone posted to let you know how the batts continue to perform.

Thanks to everyone who helped out with good advice - Rich Carroll, Jim Dawson, Ted Lowe, and Ken Simmermon.

Long live EVs and take care of those Lithiums!!!!