Battery Pack Issues And Advice after 100 Total EV Miles On The SS Saturn

Well I broke the 100 total EV mile mark. I am learning more as I go.
I sent this email to James Edmonson who has logged 20,000 EV miles plus, I believe.

James Edmonson Electric VW

James Edmonson Electric VW

This could be helpful to others so I will post it here.
Here is how the correspondence went.

I think I told you about the heater being fixed. If not , I fixed it by moving the pump to the hot side pulling from the heater box and pushing toward the heater core. Heats great.

I have now over 100 EV miles! I feel like intern that did his first surgery… well that’s not a good analogy, well I feel like a new bride after the honeymoon… that’s worse, well you think of one.
BTW have
2 questions- problems

1. Battery pack and the charger
It takes 10 to 16 hours to charge the pack. If I get home and ran it down good the pack will be only charged 80% in the morning. If not discharged too bad the 10 hours over night will charge it. I am using the Quick Charge brand 115 volt input and I believe it is rated at 8 amp draw. I am using a short extension cord with 12 gauge wires. This morning I went to the charger and it was at 99% charged its readout and the voltage was at 181 volts (gassing stage). That part seemed good. I believe I will have to get a bigger charger maybe a 230 volt charger. Wonder if I can keep both wired up and use either one depending on where I am at.
2. Drive 25 miles and battery pack getting low. Sounds way too soon. I was hoping for 50 miles on a charge. I am driving 55 mph and running the heater the first half of trip, 4000 watt draw on the heater elements plus the pump and blower motor.

Daniel Lynn

James reply……
Hi Daniel,

Good news about getting the heater to work.
I think that part of your range problems directly relates to the use of the heater. 4k watts will draw about 30 amps at 144v, as the voltage drops the amperage goes up. Under load (acceleration) the voltage may drop to 100 volts, now you are drawing 40 amps to maintain 4k watts. As the voltage lags further because of use the greater the amperage draw is and the faster you will deplete your useable voltage. Try using the heater intermittently as needed just to knock the edge off of the cold. Even with the huge battery pack in my ranger I can only get about 45-50 miles of range if I drive 55mph with the heater on constantly.
The next thing that is effecting your range is the fact that you are in the early phase of your battery pack’s life. The available energy that the pack can deliver will increase with each cycle of charge and discharge for the first 50 or so charges. It will plateau for about the next 200 to 500 charges depending on the DOD. The next 100 or so cycles will have a rapid decline in the available energy until the pack becomes useless because the range has dropped below what ever you need as a minimum.

The next thing that is killing your range is speed. Just like crack, speed kills. I lived in J town for 20+ years, unless you are on the bypass or I-40 there are very few streets that you can drive 55 mph on. Even then, the minimum speed allowable on those roads is 20 mph below the posted speed. ( 50 mph on I-40 and 35 mph on the bypass.) You would be surprised at the difference in range between 30 mph and 50 mph. At 30 mph you can push a brick through the air with negligible resistance, at 50 mph you need a tear drop shaped vehicle to have the same lack of resistance. The force difference eats up your volts and decreases your range. In my truck I can drive 30 mph for about 160 miles, at 40 mph I can get about 90 mile s, at 45 mph about 75 miles, at 55 mph about 60 miles, and at 65 mph about 30 miles. I am afraid to drive a 75 mph for any distance because I might get stranded some where 5 – 10 miles down the road with a dead pack, so I have no hard data at that speed.

The next thing that is keeping your range down is the ambient temp. It is winter time and the average temp around here has been just above a witch’s t— in a brass bra for the past few weeks. This is slowing down the rate of the chemical reaction in your batteries and decreasing the truly available voltage. I don’t have any data on my ranger but on my jetta with a new pack in the summer I could get 54 miles at 50 mph easily, In the winter with temps in the 30-40 range I could only go about 35 miles. At 20F I could barely make it to Selmer at 45mph (about 25 miles from my house). In the teens, I just didn’t drive electric as I had no effective heater other than the heated seats and my range would have been useless to me. Getting half way to Selmer wouldn’t help that poor schmuck asleep on the OR table waiting for me to remove his bad gallbladder.

So, to recap….minimize the heater use, speed kills, cold temp is a volt hoarding b—-, and the more you cycle the further you can go. Oh, and the green light does not mean the same thing on the street as is does a the Jackson drag strip. You don’t have to prove anything to that guy next to you in the Boxter.

Now, about the charger. If you are only drawing about 8 amps then you are lucky that it is only taking 16 hours to recharge. My Zivan NG3 at 120 V AC draws 28A at start up for a few min, then drops to 20 A up to 80% of full charge, then it drops to 13A from 80% to 99% then down to about 2 amps as a finishing and maintaining charge. To answer your question, I have both a 120 V AC charger and a 240 volt charger in my ranger. They are wired so that I can use either one of them at a time but not both. When power is on to the 240V charger a relay keeps the 120 v charger off and visa versa. I have however found that when the 120 V charger is plugged in that one pole of the 240V plug is hot. It bit me once. Short of rewiring the whole charger system there is nothing that I can do about this so I just keep that in mind when charging with 120V.

Your EV experience is like a boxer’s career. You worked out hard for a while with little gratification until you could get into the ring for your first bout. Hurray, you won! Now you have to maintain. If you do then you will have a good ride for awhile. A little rope-a-dope, a little float charge, a little trash talk with the media and a few failures on the road. Then as time goes by the road failures start to catch up with you and recharging you batteries over night is not enough…it may take days. Other parts begin to let you down. You may loose your bearings. And before you know it that old carcass has let you down. But, the soul of the fighter is still there and has plenty of life left in it that can be transferred to the next contestant.
If I can answer any other questions or confuse you in any other way just let me know.

James Edmonson M.D.

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