@iEnam can you edit the code on that battery LED guage and change it to this to confirm if it works for you? I found what I would call a "proper" way to handle this. I am getting this Flux thing figured out.
import "date"
from(bucket: "${bucket}")
|> range(start: date.sub(d: 7d, from: v.timeRangeStart), stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "battery")
|> filter(fn: (r) => r["_field"] == "value")
|> filter(fn: (r) => r["${tagName}"] =~ /^${battery:regex}$/)
//This keeps last entry for each device and puts it into a single table
|> last()
|> map(fn: (r) => ({name:r["${tagName}"], _value:r._value, }))
|> sort()
