HP Deskjet 870cxi 870k Ink Cartridges
Shop ink cartridges for your HP Deskjet 870cxi and 870k printers, which use the HP 45 ink cartridge series. Ink Depot has been supplying reliable consumables for these printers since Jul 2007. These classic workhorse desktop inkjets rely exclusively on high-capacity black ink to produce crisp text documents for home office and daily workplace paperwork. Choosing compatible 45 (51645AA) cartridges provides substantial savings over genuine options for high-volume text printing. Our 4.8 Google rating reflects a long-standing track record of premium cartridge performance.
Expected print output and page yields
Page yields for HP 45 (51645AA) ink cartridges are determined under ISO/IEC standard testing, reflecting coverage across standard text documents. Real-world output depends on document density and print frequency, with routine black text pages yielding consistent coverage across daily office tasks.
| Cartridge Number | Type | Colour | Page Yield | Cost Per Page |
|---|---|---|---|---|
| 45 | Standard | Black | 883 | $0.15 |
Cost Per Page = Total Cartridge Price ÷ Page Yield (at 5% coverage). Prices based on Genuine cartridges.
Choosing between genuine and compatible cartridges
Under Australian Consumer Law, using compatible cartridges does not void your printer warranty. Choosing compatible 45 (51645AA) cartridges gives you an economical way to maintain heavy text output while keeping printing costs low. Read our genuine vs compatible cartridge guide to evaluate performance differences.
Practical buying advice and delivery details
If you print high volumes of text documents, switching to compatible 45 (51645AA) cartridges significantly reduces operational expenditure. If they ever fail to meet your expectations, compatible cartridges are protected by our money-back guarantee under our returns policy. Free delivery applies on all orders over $99. We dispatch quickly from local distribution warehouses in Perth, Brisbane, Sydney, Melbourne, and Adelaide. Browse our full range of HP ink cartridges for dependable replacement options.
Essential cartridge tip
Because the HP 45 (51645AA) cartridge integrates the printhead directly into the cartridge body, replacing the ink cartridge also completely refreshes the printhead mechanism, restoring clean text output if fine lines or letters begin to look faded.
Frequently Asked Questions
Do the HP Deskjet 870cxi and 870k use the exact same ink cartridges?
Yes, both the Deskjet 870cxi and 870k share the exact same internal architecture and take HP 45 (51645AA) black ink cartridges interchangeably.
Why does the printhead get replaced with every new HP 45 cartridge?
The HP 45 series uses an integrated printhead design where the firing nozzles are built into the physical cartridge structure rather than remaining permanently inside the printer.
Will a compatible HP 45 cartridge dry out if left unused for extended periods?
Like genuine cartridges, thermal inkjet nozzles can dry out if left idle in unsealed printers for months; printing a single test page fortnightly helps keep the ink channels flowing cleanly.
Can I install higher-capacity versions of the HP 45 black cartridge?
The HP 45 (51645AA) is already a high-capacity cartridge designed for high-volume document printing, so there are no separate XL variants for this specific series.
