update and testing . . . .
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I've just bagged myself a third Valence U27-12XP Series 12V 138ah Lifepo4
and they have more in stock - get yours here -->
lifepo4 battery Valence U27-12XP Series 12V 130 amp | eBay
1off lifepo4 battery Valence U27-12XP Series 12V 130 amp. Condition is Used. sold as is where is you decide if fit for use, no warranty given or implied, improper use can lead to injury or death, and no returns. Cash on Collection in person only, and you can pick out your own, check out...
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its in to its time to start testing . . .
ID-3 this time . . .
first up is a full top charge to 100% . . . The trusty Victron 12/20/1 had this done in no time.
next up was to fully discharge the battery via a power meter. . . . and read the ah, then full charge to 100% again.
that way we will have discharged, and recharged value that the battery can achive, , ,
we then compaire this to the as-new value . . . . for this battery its 138ah new.
lets get started . .
first up lets hook it up.
were using these meters to monitor.
BM2,
current shunt,
bmv712
12v round meter
victron conect to inverter,
all connected via the bus bars . .
lets start so . . . . . 12A to start with via a heat gun . .
all good, . . .
so time to up the power draw . . .
now adding a dehumidifyer . . . now drawing 45A.
this is what we have on the thermals at 45A draw , . . .
heatgun and inverter . .
.
dehumidifyer and battery in background . .
.
notice the heat build up over the trip switch isolator !!!!
.
hours later we were at 126ah and the battery voltage started to fall of the clif...
.
.
the bm2 results back up the inline meter . . . . 129ah used.
and a final BMS check . . . . (note the issue with internal BMS showing 99% full when its empty - but doesnt effect us here)
so there we go, the discharge test acheived 126 129 ah from a 138ah battery
im very happy with that.
edit:
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start rest voltage @ 13.5V
45A draw cycling for about 3.5hrs.
discharged capacity from full charge down to 11v cut off @ 126ah.
recharged capacity from 11v cut off to 14.6v float/storage (less than 1amp draw) @ 1256ah
91% capacity from new spec (138ah / 126ah * 100 = 91.3)
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