Philips HeartStart FRx Pads & Battery: Part Numbers & the Infant/Child Key
The Philips HeartStart FRx is built for tougher environments than the OnSite — and it handles both consumables and paediatric patients differently. Get one detail wrong and you order pads that will not fit.
Part numbers at a glance
-
Pads: SMART Pads II —
989803139261 -
Battery: HeartStart battery —
M5070A -
Aviation battery (FAA): Battery —
989803139301 - Pediatric: Infant/Child Key — no separate pads required
Shares a battery with the OnSite. Never shares pads.
The M5070A battery powers both the FRx and the HeartStart OnSite. The pads do not cross over: the FRx needs SMART Pads II 989803139261, while the OnSite takes M5071A. On a site running both models you can standardise battery stock but must keep pads separate.
The Infant/Child Key
Most AEDs need a second set of paediatric pads. The FRx does not. Instead you insert an Infant/Child Key into the device and the same adult SMART Pads II stay in place — the key tells the FRx to deliver a reduced paediatric energy level.
Two practical consequences worth training on:
- Nothing expires. The key is hardware, not a consumable, so there is no paediatric date to diary — a genuine advantage over models where the pediatric pads are the item most often found out of date.
- It can go missing. Because it is a small separate object, the failure mode shifts from "expired" to "nobody knows where it is". Keep it with the device and check for it during inspections.
If you also run HeartStart OnSite units, note the drill is different: the OnSite uses a separate M5072A paediatric cartridge. Same brand, two different procedures.
Replacement intervals
FRx pads follow roughly a two-year interval, and the M5070A battery around four years in standby — so expect to replace pads about twice per battery. Always follow the dates printed on your own parts, and replace pads immediately after any use.
Our FRx Maintenance Package bundles both.
Frequently asked questions
What pads does the Philips HeartStart FRx use?
The FRx uses SMART Pads II, part 989803139261. These are not interchangeable with the HeartStart OnSite pads (M5071A).
Does the FRx need separate pediatric pads?
No. The FRx uses an Infant/Child Key inserted into the device, with the adult SMART Pads II left in place. The key switches the unit to a paediatric energy level.
Is the FRx battery the same as the OnSite battery?
Yes. Both use the M5070A battery. Only the pads differ between the two models.
Reorder for your HeartStart FRx
Genuine Philips SMART Pads II and batteries, with a reminder before the next set expires.
Related
- AED pads & batteries by model — full compatibility guide
- Philips HeartStart OnSite pads & battery
- How often should you replace AED pads and batteries?
Last reviewed: 18 August 2026. Part numbers checked against our live catalogue.
