Xantrex Link 2000, Owner'S Manual, Page: 28 / 43

27
Surrette and Rolls Batteries
Model Volts Res. Min. 20-Hr. Rating "n"
EHG-208 6 345 208 1.42
EIG-225 6 350 225 1.54*
EIG-262 6 395 262 1.72*
24/90 12 165 90 1.16
27/12M 12 190 112 1.23
30H/108 12 230 108 1.08
HT/4D 12 348 170 1.15
HT/8D 12 450 221 1.20
*Use Max allowed "n" of 1.50
TYPICAL PEUKERT'S EXPONENTS
log
t
2
- log
t
1
log
I
1
- log
I
2
n =
log 20 - log 7.45
log 25 - log 11.25
=
=
1.301 - 0.872
1.398 - 1.051
= 1.24
CALCULATING PEUKERT'S EXPONENT
Example of using Reserve Minutes @ 25 amps
and the 20-hour rate to calculate " n ".
First convert Reserve Minutes to hours, then find the discharge current
at the 20-hour rating. Finally use a calculator to solve the arithmetic.
Trojan T-105:
Reserve Minutes = 447 min @ 25 amps.
t
1
= 447 min = 447/60 = 7.45 hrs
I
1
= 25 amps
20-Hour rating = 225 Ah
t
2
= 20 hours
I
2
= 225 amp hours/20 hours = 11.25 amps