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  <xs:element id="blln_TemporaryEquityMinimumNumberOfSharesOutstandingDirectorElectionThreshold" abstract="false" name="TemporaryEquityMinimumNumberOfSharesOutstandingDirectorElectionThreshold" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="blln_TemporaryEquityElectionOfDirectorsNumberOfDirectorsEntitledToBeElected" abstract="false" name="TemporaryEquityElectionOfDirectorsNumberOfDirectorsEntitledToBeElected" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="blln_TemporaryEquityDissolutionAsPartOfReorganizationMinimumPercentage" abstract="false" name="TemporaryEquityDissolutionAsPartOfReorganizationMinimumPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="blln_LesseeOperatingLeaseNumberOfRenewalOptions" abstract="false" name="LesseeOperatingLeaseNumberOfRenewalOptions" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="blln_LesseeOperatingLeaseLeaseNotYetCommencedInitialAnnualRentalRate" abstract="false" name="LesseeOperatingLeaseLeaseNotYetCommencedInitialAnnualRentalRate" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_LesseeOperatingLeaseLeaseNotYetCommencedAnnualRentIncreasePercentage" abstract="false" name="LesseeOperatingLeaseLeaseNotYetCommencedAnnualRentIncreasePercentage" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
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  <xs:element id="blln_A2024NotesMember" abstract="true" name="A2024NotesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="blln_DebtCovenantTrancheDomain" abstract="true" name="DebtCovenantTrancheDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_DebtCovenantTrancheOneMember" abstract="true" name="DebtCovenantTrancheOneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_DebtCovenantTrancheTwoMember" abstract="true" name="DebtCovenantTrancheTwoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_DebtCovenantTrancheThreeMember" abstract="true" name="DebtCovenantTrancheThreeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_DebtCovenantTrancheFourMember" abstract="true" name="DebtCovenantTrancheFourMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_DebtInstrumentRedemptionPeriodSixMember" abstract="true" name="DebtInstrumentRedemptionPeriodSixMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_OberlandCapitalMember" abstract="true" name="OberlandCapitalMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_A2021LSACommonStockWarrantsMember" abstract="true" name="A2021LSACommonStockWarrantsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_A2022LSACommonStockWarrantsMember" abstract="true" name="A2022LSACommonStockWarrantsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_LoansPayableCapitalAdvancesNumberOfTranches" abstract="false" name="LoansPayableCapitalAdvancesNumberOfTranches" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="blln_DebtInstrumentRedemptionInternalRateOfReturnGenerated" abstract="false" name="DebtInstrumentRedemptionInternalRateOfReturnGenerated" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="blln_DebtInstrumentCovenantTrailingSixMonthWorldwideNetRevenueMinimum" abstract="false" name="DebtInstrumentCovenantTrailingSixMonthWorldwideNetRevenueMinimum" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_DebtInstrumentCovenantTrailingSixMonthGrossMarginMinimum" abstract="false" name="DebtInstrumentCovenantTrailingSixMonthGrossMarginMinimum" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="blln_DebtInstrumentRedemptionPeriod" abstract="false" name="DebtInstrumentRedemptionPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="blln_DebtInstrumentCovenantLiquidityConditionRatio" abstract="false" name="DebtInstrumentCovenantLiquidityConditionRatio" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:decimalItemType"/>
  <xs:element id="blln_DebtInstrumentRevenueParticipationAgreementPercentOfQuarterlyNetRevenue" abstract="false" name="DebtInstrumentRevenueParticipationAgreementPercentOfQuarterlyNetRevenue" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="blln_DebtInstrumentRevenueParticipationAgreementMaximumAnnualNetRevenue" abstract="false" name="DebtInstrumentRevenueParticipationAgreementMaximumAnnualNetRevenue" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_DebtInstrumentRevenueParticipationAgreementPrincipalAmountOfNotes" abstract="false" name="DebtInstrumentRevenueParticipationAgreementPrincipalAmountOfNotes" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_PaymentsForRevenueParticipationAgreement" abstract="false" name="PaymentsForRevenueParticipationAgreement" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_LoansPayableToBankNumberOfEqualMonthlyPayments" abstract="false" name="LoansPayableToBankNumberOfEqualMonthlyPayments" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="blln_LoansPayableToBankInterestOnlyPeriod" abstract="false" name="LoansPayableToBankInterestOnlyPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="blln_LoansPayableToBankAmortizationPeriod" abstract="false" name="LoansPayableToBankAmortizationPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="blln_LoansPayableToBankFinalPaymentPercentageOfAdvancedAmount" abstract="false" name="LoansPayableToBankFinalPaymentPercentageOfAdvancedAmount" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="blln_LoansPayableToBankFinalPayment" abstract="false" name="LoansPayableToBankFinalPayment" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_LossOnExtinguishmentOfDebtIncrementalExpense" abstract="false" name="LossOnExtinguishmentOfDebtIncrementalExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_PaymentsOfLoanTerminationFees" abstract="false" name="PaymentsOfLoanTerminationFees" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_LossOnExtinguishmentOfDebtUnamortizedDebtIssuanceCosts" abstract="false" name="LossOnExtinguishmentOfDebtUnamortizedDebtIssuanceCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_LossOnExtinguishmentOfDebtPrepaymentFee" abstract="false" name="LossOnExtinguishmentOfDebtPrepaymentFee" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_ClassOfWarrantOrRightRightToReturnWarrantsToCompanyCashValue" abstract="false" name="ClassOfWarrantOrRightRightToReturnWarrantsToCompanyCashValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_ClassOfWarrantOrRightSharesWarrantsIssuedDuringPeriod" abstract="false" name="ClassOfWarrantOrRightSharesWarrantsIssuedDuringPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="blln_LockUpAgreementNumberOfDays" abstract="false" name="LockUpAgreementNumberOfDays" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="blln_DebtInstrumentCovenantScheduleAxis" abstract="true" name="DebtInstrumentCovenantScheduleAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="blln_DebtInstrumentCovenantScheduleDomain" abstract="true" name="DebtInstrumentCovenantScheduleDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_Q12025Member" abstract="true" name="Q12025Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_Q22025Member" abstract="true" name="Q22025Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_Q32025Member" abstract="true" name="Q32025Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_Q42025Member" abstract="true" name="Q42025Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_Q12026Member" abstract="true" name="Q12026Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_Q22026Member" abstract="true" name="Q22026Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_Q32026Member" abstract="true" name="Q32026Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_Q42026Member" abstract="true" name="Q42026Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_ThereafterMember" abstract="true" name="ThereafterMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_WarrantsAndRightsOutstandingGrantDateFairValue" abstract="false" name="WarrantsAndRightsOutstandingGrantDateFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_The2018PlanMember" abstract="true" name="The2018PlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_The2025ESPPMember" abstract="true" name="The2025ESPPMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_ChiefExecutiveOfficerAndCoFounderMember" abstract="true" name="ChiefExecutiveOfficerAndCoFounderMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_ChiefTechnologyOfficerAndCoFounderMember" abstract="true" name="ChiefTechnologyOfficerAndCoFounderMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_ShareBasedPaymentArrangementEarlyExerciseOptionsMember" abstract="true" name="ShareBasedPaymentArrangementEarlyExerciseOptionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="blln_CommonStockConvertibleNonActiveBoardMemberTerm" abstract="false" name="CommonStockConvertibleNonActiveBoardMemberTerm" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="blln_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedPerParticipant" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedPerParticipant" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
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  <xs:element id="blln_OptionsToPurchaseCommonStockMember" abstract="true" name="OptionsToPurchaseCommonStockMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_StockOptionsAvailableForFutureGrantsMember" abstract="true" name="StockOptionsAvailableForFutureGrantsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsFairValueOfCommonStock" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsFairValueOfCommonStock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="blln_CostOfProductAndServiceSoldMember" abstract="true" name="CostOfProductAndServiceSoldMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_DeferredTaxAssetsCapitalizedResearchAndDevelopment" abstract="false" name="DeferredTaxAssetsCapitalizedResearchAndDevelopment" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_DeferredTaxAssetsLeaseLiabilities" abstract="false" name="DeferredTaxAssetsLeaseLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_DeferredTaxLiabilitiesRightOfUseAssets" abstract="false" name="DeferredTaxLiabilitiesRightOfUseAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="blln_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseDebtExtinguishmentGainOrLossAmount" abstract="false" name="EffectiveIncomeTaxRateReconciliationNondeductibleExpenseDebtExtinguishmentGainOrLossAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="blln_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseChangeInFairValueOfTermLoanPercent" abstract="false" name="EffectiveIncomeTaxRateReconciliationNondeductibleExpenseChangeInFairValueOfTermLoanPercent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="blln_AntidilutiveSecuritiesWarrantsToPurchaseCommonStockMember" abstract="true" name="AntidilutiveSecuritiesWarrantsToPurchaseCommonStockMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_AntidilutiveSecuritiesWarrantsToPurchaseRedeemableConvertiblePreferredStockMember" abstract="true" name="AntidilutiveSecuritiesWarrantsToPurchaseRedeemableConvertiblePreferredStockMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="blln_AntidilutiveSecuritiesUnvestedEarlyExercisedOptionsMember" abstract="true" name="AntidilutiveSecuritiesUnvestedEarlyExercisedOptionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
