Roland Wiench wrote:
You did not state what the ampere hour rating of these batteries are. I was
searching the web and came across the Interstate Battery specifications for the
6-volt battery. The local independent auto Parts Store which I have been going
to since the 50's started to handle the Interstate Battery line which is only 5
blocks from me and delivers items to my house.
So I went to the Parts Store (which is actual name of the store) and I notice
the Interstate Battery battery truck was there. I walk in and I want to see
the data and specifications of these batteries.
The Interstate battery person said, I have it right here in this book that was
laying on the counter. I said, I like to see the data on the 250 ah 6-volt
battery. He said they do not make this battery over 220 ah, but we furnish the
250 ah one which we get from the U.S. Battery Co.
I said I will take it without any hesitation. I said I need for them to be all
the same manufacture date, auto post with deep imbedded stud (use this stud
connection for a BMS and also to put a greater internal pressure of the auto
post against the internal surfaces of a battery clamp.
I also wanted to have these battery balance (battery balance means the ampere
hour and voltage and the deep cycle cranking ampere at 75 ampere for a certain
amount of time within a 0.1 V, 5% A and AH of each other. The Interstate guy
said this will about double the cost of the battery as a option cost. You can
do this testing yourself with the equipment we furnish the Parts Store battery
shop. We normally ship 240 of these batteries were you can test out the best
30 batteries you need.
Interstate deliver the batteries right to my house. The batteries were in a
U.S. Battery package. I pick out 30 batteries that where match with a voltage
of 6.44 volts and the cranking ampere was at 1000 amp plus or minus 5 ampere.
Had to go two pallets of batteries to get this tolerance.
Knowing that the actual drive test and recharge may change this results, One
battery of 30 batteries was out of tolerance, so they change this battery for
me.
These batteries where install on September 4 2009 and had put on 2729 cycles on
them driving only 4165 miles. In this roller coaster roads, the actual motor
on time is about 3000 miles and the motor off time is the remainder.
Today the AH per mile and charging time over the same exact route and
temperature is still 3.3 ah per mile and 7.5 minutes of charging at 20 amperes
at 250 volts.
The cost of the batteries ran $125.00 for the 250 AH.
Excellent, Roland. You really went the extra mile to get good batteries.
$125 each is also a great price.
Did you happen to do an amphour test to see what the actual capacity
was? Were they really 250ah at the 20-hour rate? How many minutes at 75
amps?
The ones I bought from Sam's Club were 8v 175 amphour. I waited until
they got a fresh shipment in, and got a set of 15 of all the same date
code. I didn't test the 20-hour rate, but did test the 75-amp capacity.
One of the 15 was about 10% lower than the rest; I exchanged it for
another one from the same batch. They are 3 years old now and still
doing well. I'll have to run another capacity test though and see where
they are at today.
--
There are few industries with more BS than the battery industry.
Elon Musk
--
Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm
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