For a current sense resistor in Bulgarian battery storage electronics, Walsin Technology (Walsin) lists 11,616 current sense part numbers, 1,188 of them metal. A 2512, 1 milliohm shunt brief returns 28, rated 1 W to 3 W. Venatech Limited, an authorised Walsin distributor in Hong Kong, crosses and quotes them.
Venatech Limited, an authorised Walsin distributor in Hong Kong, wrote this for BMS and power engineers near Sofia, Bulgaria, who choose the shunt that measures pack and module current in battery energy storage systems, and for the EMS teams who build those boards. We parsed Metal_Low_Ohm_Current_Sense_Chip_Resistor__1of1.xlsx (1,188 parts), Thick_Film_Low_Ohm_Current_Sense_Chip_Resistor__1of1.xlsx (10,428 parts) and our ready-stock list as at 23 September 2026. Every part number is real, and the market facts come from one report fetched on 11 November 2026.
What is IPS building near Sofia?
Bulgaria’s first battery storage gigafactory. According to ESS News on 13 October 2025, IPS inaugurated a battery storage factory near Sofia with 3 GWh of annual capacity, recognised as a Strategic Project under the EU Net-Zero Industry Act, and an expansion at the Hemus High Tech Industrial Park was expected to lift output to 5 GWh by the second quarter of 2026.
The report says IPS makes most components in-house, including battery modules and packs, battery management systems, control units and inverters, while buying in its LFP cells. Those are the report’s statements, not ours. Our conclusion: battery management and inverter boards built in Bulgaria each carry at least one shunt per measured current path. We have no relationship with IPS and say nothing about what it buys.
How many current sense resistors does Walsin list?
11,616 distinct part numbers. We counted 11,616 distinct Walsin current sense resistors across the two .xlsx files: 10,428 thick film and 1,188 metal (metal plate and metal foil), with 625 of the metal parts in the 2512 size that BMS shunts favour.
The metal families run from 0306 to 2512; the thick-film families give the higher-ohm sense values used in low-current paths. Our comparison of thick-film versus metal current sense resistors explains why metal wins below about 10 milliohm, and the chip resistor range lists every family.
Which Walsin 2512, 1 milliohm current sense resistors cross a BMS shunt brief?
Twenty-eight part numbers. We filtered the metal file to 2512 and 1 milliohm and found 28 Walsin part numbers: 14 at 1%, 14 at 5%, rated 1 W, 2 W or 3 W, with TCR from plus or minus 70 to plus or minus 100 ppm/°C, and half of them in J-suffix variants.
The table takes a typical module-shunt brief, 2512, 1 milliohm, 1%, at least 2 W, and shows the closest rows. Your incumbent goes in the last column.
| Walsin part | Tolerance | TCR (ppm/°C) | Rated power | Match / mismatch with a 1 milliohm, 1%, 2 W brief | Your incumbent |
|---|---|---|---|---|---|
WW25AR001FTL |
1% | ±70 | 3 W | Match, extra power margin | |
WW25BR001FTL |
1% | ±70 | 3 W | Match, extra power margin | |
WW25NR001FTL |
1% | ±70 | 2 W | Match on every field | |
WW25KR001FTL |
1% | ±70 | 2 W | Match on every field | |
WW25RR001FTL |
1% | ±75 | 2 W | Match, slightly wider TCR | |
WW25JR001FTL |
1% | ±70 | 1 W | Mismatch: lower power | |
WW25RR001JTL |
5% | ±75 | 2 W | Mismatch: tolerance is wider |
A match is a match on export fields. Pad layout, Kelvin sense connections and pulse ratings are in Walsin’s datasheet, and the footprint differs between metal-plate families, so confirm the land pattern before you swap.
How much power does a 1 milliohm shunt dissipate in a battery module?
I squared times R: 1 W at about 32 A. With a 1 milliohm shunt, dissipation is 0.1 W at 10 A, 0.9 W at 30 A and 2.5 W at 50 A, so a 50 A continuous path already needs a 3 W rated part before any derating for temperature.
That arithmetic is why the 3 W rows matter to a storage design, where module current is continuous for hours rather than peaking for seconds. Derate using Walsin’s power curve at your board temperature, and weigh a lower value, such as 0.5 milliohm, against the lost signal at the amplifier. Our walkthrough of passives for a battery management system covers the rest of the sense chain.
Which Walsin current sense lines are on the Hong Kong shelf?
Three thick-film lines. We matched both current sense files against our ready-stock list as at 23 September 2026 and found three Walsin 0805 thick-film current sense lines on the shelf: WW08WR270FTL (0.27 ohm), WW08WR390FTL (0.39 ohm) and WW08WR470FTL (0.47 ohm), all 1% and 1/4 W.
| Walsin part on the shelf | Size | Value | Tolerance | Rated power |
|---|---|---|---|---|
WW08WR270FTL |
0805 | 0.27 ohm | 1% | 1/4 W |
WW08WR390FTL |
0805 | 0.39 ohm | 1% | 1/4 W |
WW08WR470FTL |
0805 | 0.47 ohm | 1% | 1/4 W |
Those suit auxiliary supplies and fan or pump drives on a storage cabinet’s control board. The 2512 metal shunts above are quoted to order; request a quote and we source them through our authorised Walsin channel. The ready-stock list is a dated snapshot, never live-synced, and we give no stock or lead-time promise.
How can Venatech help a battery storage maker in Bulgaria?
How Venatech helps: send the shunt lines, get the Walsin rows. Venatech Limited is the authorised Walsin distributor in Hong Kong, and VenaMatch decodes 18 manufacturers’ part numbers and crosses 800,000+ parts to Walsin, with every field marked.
Paste up to 500 part numbers into the cross-reference tool, or upload a BOM. We serve small lots from Hong Kong, quote fast and help you check each cross; request a quote through the site. Walsin is the line we are authorised for; Stackpole and Viking are lines we supply. We give no customs advice; confirm with your compliance team.
The short version
Battery storage production around Sofia means BMS and inverter boards, and each needs a shunt. Walsin covers that with 11,616 current sense resistors; a 2512, 1 milliohm brief returns 28 metal parts rated up to 3 W, and three 0805 thick-film sense lines were on our Hong Kong shelf as at 23 September 2026.
Send us your shunt value, current and board temperature, and we will return the Walsin rows with the power margin worked out. What continuous current does your module shunt carry?
Related reading
- Low-ohm current sense: thick film versus metal
- Passives for a battery management system
- Passives for a solar string inverter
- Free cross-reference tool and ready-stock snapshot
Last reviewed 11 Nov 2026.
Sources
Fetched 11 November 2026.
- ESS News, “IPS inaugurates Bulgaria’s first battery storage gigafactory”, 13 October 2025: https://www.ess-news.com/2025/10/13/ips-inaugurates-bulgarias-first-battery-storage-gigafactory
Frequently asked questions
What battery storage production is there near Sofia, Bulgaria?
ESS News reported on 13 October 2025 that IPS inaugurated a 3 GWh a year battery storage factory near Sofia, with an expansion expected to reach 5 GWh by the second quarter of 2026. These are the report’s figures.
How many current sense resistors does Walsin make?
We counted 11,616 distinct Walsin current sense part numbers: 10,428 thick film and 1,188 metal, with 625 metal parts in 2512.
Which Walsin part crosses a 2512, 1 milliohm, 1% shunt?
WW25NR001FTL and WW25KR001FTL match a 2 W brief on every export field, and WW25AR001FTL and WW25BR001FTL give 3 W. Confirm the land pattern against Walsin’s datasheet.
What power rating does a 1 milliohm shunt need at 50 A?
At 50 A a 1 milliohm shunt dissipates 2.5 W, so choose a 3 W part and derate for board temperature using the datasheet curve.
Does Venatech stock current sense resistors in Hong Kong?
As at 23 September 2026 our snapshot held three 0805 thick-film current sense lines. The 2512 metal shunts are quoted to order through our authorised Walsin channel; we make no lead-time promise.
Is Venatech authorised by Walsin?
Yes. Venatech Limited is an authorised Walsin distributor in Hong Kong, and serves buyers in Bulgaria in small lots.