diff --git a/lib/plugins/wallet/mock-wallet/mock-wallet.js b/lib/plugins/wallet/mock-wallet/mock-wallet.js
index a7a9493c..f8eb7a7f 100644
--- a/lib/plugins/wallet/mock-wallet/mock-wallet.js
+++ b/lib/plugins/wallet/mock-wallet/mock-wallet.js
@@ -65,7 +65,7 @@ function sendCoinsBatch (account, txs, cryptoCode) {
   sendCount = sendCount + txs.length
   return new Promise((resolve, reject) => {
     setTimeout(() => {
-      const cryptoSum = _.reduce((acc, value) => acc.add(value.crypto_atoms), BN(0), txs)
+      const cryptoSum = _.reduce((acc, value) => acc.plus(value.crypto_atoms), BN(0), txs)
       if (isInsufficient(cryptoSum, cryptoCode)) {
         console.log('[%s] DEBUG: Mock wallet insufficient funds: %s',
           cryptoCode, cryptoSum.toString())
diff --git a/lib/tx-batching.js b/lib/tx-batching.js
index fef98b93..0e7ce6ee 100644
--- a/lib/tx-batching.js
+++ b/lib/tx-batching.js
@@ -12,27 +12,6 @@ function createTransactionBatch (cryptoCode) {
   return db.one(sql, [uuid.v4(), cryptoCode])
 }
 
-function closeTransactionBatch (batch) {
-  const sql = `UPDATE transaction_batches SET status='ready', closed_at=now() WHERE id=$1`
-
-  return db.none(sql, [batch.id])
-}
-
-function confirmSentBatch (batch, tx) {
-  return db.tx(t => {
-    const q1 = t.none(`UPDATE transaction_batches SET status='sent', error_message=NULL WHERE id=$1`, [batch.id])
-    const q2 = t.none(`UPDATE cash_in_txs SET tx_hash=$1, fee=$2, send=true, send_confirmed=true, send_time=now(), send_pending=false, error=NULL, error_code=NULL WHERE batch_id=$3`, [tx.txid, tx.fee.toString(), batch.id])
-
-    return t.batch([q1, q2])
-  })
-}
-
-function setErroredBatch (batch, errorMsg) {
-  const sql = `UPDATE transaction_batches SET status='failed', error_message=$1 WHERE id=$2`
-
-  return db.none(sql, [errorMsg, batch.id])
-}
-
 function addTransactionToBatch (tx) {
   const sql = `SELECT * FROM transaction_batches WHERE crypto_code=$1 AND status='open' ORDER BY created_at DESC LIMIT 1`
   const sql2 = `UPDATE cash_in_txs SET batch_id=$1 WHERE id=$2`
@@ -46,38 +25,64 @@ function addTransactionToBatch (tx) {
     .then(batch => db.none(sql2, [batch.id, tx.id]))
 }
 
-function getBatchTransactions (batch) {
-  const sql = `SELECT * FROM cash_in_txs WHERE batch_id=$1`
-  return db.manyOrNone(sql, [batch.id])
+function closeTransactionBatch (t, batch) {
+  const sql = `UPDATE transaction_batches SET status='ready', closed_at=now() WHERE id=$1`
+
+  return t.none(sql, [batch.id])
 }
 
-function getBatchesByStatus (statuses) {
+function confirmSentBatch (t, batch, tx) {
+  return t.none(`UPDATE transaction_batches SET status='sent', error_message=NULL WHERE id=$1`, [batch.id])
+    .then(() =>
+      t.none(`UPDATE cash_in_txs SET tx_hash=$1, fee=$2, send=true, send_confirmed=true, send_time=now(), send_pending=false, error=NULL, error_code=NULL WHERE batch_id=$3`, [tx.txid, tx.fee.toString(), batch.id])
+    )
+}
+
+function setErroredBatch (t, batch, errorMsg) {
+  const sql = `UPDATE transaction_batches SET status='failed', error_message=$1 WHERE id=$2`
+
+  return t.none(sql, [errorMsg, batch.id])
+}
+
+function getBatchTransactions (t, batch) {
+  const sql = `SELECT * FROM cash_in_txs WHERE batch_id=$1`
+  return t.manyOrNone(sql, [batch.id])
+}
+
+function getBatchesByStatus (t, statuses) {
   const sql = `SELECT *, EXTRACT(EPOCH FROM (now() - created_at)) as time_elapsed FROM transaction_batches WHERE status in ($1^)`
 
-  return db.manyOrNone(sql, [_.map(pgp.as.text, statuses).join(',')])
+  return t.manyOrNone(sql, [_.map(pgp.as.text, statuses).join(',')])
 }
 
-function submitBatch (settings, batch) {
-  getBatchTransactions(batch)
+function submitBatch (t, settings, batch) {
+  getBatchTransactions(t, batch)
     .then(txs => {
       wallet.sendCoinsBatch(settings, txs, batch.crypto_code)
-        .then(res => confirmSentBatch(batch, res))
-        .catch(err => setErroredBatch(batch, err.message))
+        .then(res => confirmSentBatch(t, batch, res))
+        .catch(err => setErroredBatch(t, batch, err.message))
     })
 }
 
 function processBatches (settings, lifecycle) {
-  getBatchesByStatus(['open', 'failed'])
-    .then(batches => {
-      _.each(batch => {
-        const elapsedMS = batch.time_elapsed * 1000
+  const transaction = t => {
+    getBatchesByStatus(t, ['open', 'failed', 'ready'])
+      .then(batches => {
+        _.each(batch => {
+          const elapsedMS = batch.time_elapsed * 1000
 
-        if (elapsedMS >= lifecycle) {
-          return closeTransactionBatch(batch)
-            .then(() => submitBatch(settings, batch))
-        }
-      }, batches)
-    })
+          if (elapsedMS >= lifecycle) {
+            return closeTransactionBatch(t, batch)
+              .then(() => submitBatch(t, settings, batch))
+          }
+        }, batches)
+      })
+  }
+
+  return db.tx(
+    new pgp.txMode.TransactionMode({ tiLevel: pgp.txMode.isolationLevel }),
+    transaction
+  )
 }
 
 module.exports = {