diff --git a/src/domain/battery.test.ts b/src/domain/battery.test.ts
index a92d0da..fe8b770 100644
--- a/src/domain/battery.test.ts
+++ b/src/domain/battery.test.ts
@@ -56,6 +56,20 @@ describe('battery domain', () => {
     expect(response.items[0]?.createTime).toBe('2026-05-10T23:00:00.000Z')
   })
 
+  test('keeps explicit window summaries for limited history slices', () => {
+    const now = new Date('2026-05-11T00:00:00.000Z')
+    const items = rows.map(toBatteryInfo)
+    const response = createBatteriesResponse(items, now, {
+      total: items.length,
+      lowPower: 1,
+      charging: 1,
+    })
+
+    expect(response.total).toBe(2)
+    expect(response.lowPower).toBe(1)
+    expect(response.charging).toBe(1)
+  })
+
   test('creates dashboard aggregate shape without using power as fake SOH', () => {
     const now = new Date('2026-05-11T00:00:00.000Z')
     const snapshot = createDashboardSnapshot(rows.map(toBatteryInfo), now)
diff --git a/src/server/api/routers/battery.router.ts b/src/server/api/routers/battery.router.ts
index d12f57e..f1c7625 100644
--- a/src/server/api/routers/battery.router.ts
+++ b/src/server/api/routers/battery.router.ts
@@ -1,4 +1,4 @@
-import { createBatteriesResponse, createDashboardSnapshot } from '@/domain/battery'
+import { createBatteriesResponse, createDashboardSnapshot, POWER_STATUS } from '@/domain/battery'
 import { os } from '@/server/api/server'
 import {
   getBatteryHistory,
@@ -63,5 +63,10 @@ export const batteries = os.battery.batteries.handler(async ({ input }) => {
 export const history = os.battery.history.handler(async ({ input }) => {
   const items = await getBatteryHistory(input.mac)
 
-  return createBatteriesResponse(items)
+  // History returns a limited window, so the counters must describe only this returned slice.
+  return createBatteriesResponse(items, new Date(), {
+    total: items.length,
+    lowPower: items.filter((item) => item.isLowPower).length,
+    charging: items.filter((item) => item.powerStatus === POWER_STATUS.CHARGING).length,
+  })
 })
diff --git a/src/server/battery/mysql.ts b/src/server/battery/mysql.ts
index 88eddd7..ec9cb6f 100644
--- a/src/server/battery/mysql.ts
+++ b/src/server/battery/mysql.ts
@@ -15,8 +15,6 @@ import { env } from '@/env'
 
 const historyLimit = 500
 const predictionHistoryLimit = 10
-const dashboardLatestLimit = 100
-
 type BatteryInfoMysqlRow = RowDataPacket & BatteryInfoSourceRow
 type CountMysqlRow = RowDataPacket & {
   total: number
@@ -314,16 +312,19 @@ export async function getLatestBatteryPage(input: LatestBatteryPageInput): Promi
   }
 }
 
-export async function getLatestBatteryPerDevice(limit = dashboardLatestLimit): Promise<BatteryInfo[]> {
+export async function getLatestBatteryPerDevice(limit?: number): Promise<BatteryInfo[]> {
+  const appliedLimit = typeof limit === 'number' && limit > 0 ? limit : undefined
+  const limitSql = appliedLimit ? '\n    LIMIT :limit' : ''
+  const queryParams = appliedLimit ? { limit: appliedLimit } : {}
+
   const [rows] = await getBatteryPool().query<BatteryInfoMysqlRow[]>(
     `
     SELECT ${sourceColumns}
     FROM ls_battery_info AS current_record
     WHERE ${latestRecordPredicate}
-    ORDER BY current_record.create_time DESC, current_record.id DESC
-    LIMIT :limit
+    ORDER BY current_record.create_time DESC, current_record.id DESC${limitSql}
   `,
-    { limit: Math.min(Math.max(limit, 1), dashboardLatestLimit) },
+    queryParams,
   )
 
   return rows.map(toBatteryInfo)