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Contact the Factory Direct
Every inquiry is routed to a battery engineer, not a sales filter. Send voltage, capacity, application and annual volume — you get a human reply within 24 hours and a costed proposal within 2 working days. Office hours 09:00–18:00 China Standard Time (UTC+8), Monday to Saturday.
Direct Channels
Reach Our Battery Engineers
Direct Channels
Reach the Team That Builds Your Packs
sales@ems-ess.com
Quotations, spec review and engineering questions — routed to the engineer who owns the product line.
+86 755 8888 6666
Phone and WhatsApp, Monday to Saturday 09:00–18:00 China Standard Time (UTC+8).
Longgang, Shenzhen
Building A, Mingjunda Industrial Park, Longgang District, Shenzhen 518100 — HQ, showroom and R&D.
Dongguan plant
Second production site — 12,000 m² combined across both bases, 8 pack lines, 1.2 GWh annual capacity.
| Buyer location | UTC offset | Your 09:00–17:00 = Shenzhen | What to expect |
|---|---|---|---|
| Shenzhen HQ | UTC+8 | 09:00–18:00 office | Live reply window, Mon–Sat |
| Frankfurt | UTC+1 | 16:00–24:00 | Live overlap 16:00–18:00 CST |
| London | UTC+0 | 17:00–01:00 | Live overlap 17:00–18:00 CST |
| New York | UTC-5 | 22:00–06:00 (+1) | Overnight reply waiting by your 09:00 |
| Los Angeles | UTC-8 | 01:00–09:00 (+1) | Reply lands before Pacific opening |
| Sydney | UTC+10 | 07:00–15:00 | Live overlap 09:00–15:00 CST |
Send Your Spec
Six fields, one screen. An engineer reads every submission — no auto-responder loop, no lead-scoring gate.
Visit or Video-Tour
12,000 m² You Can Inspect Before You Order
Serious buyers audit their supplier before the first purchase order — we encourage it. Walk the Longgang showroom, watch the Dongguan pack lines run, or book a live camera walk-through in your own timezone.
- On-site audits — both sites open to buyers: 8 pack lines from cell sorting through laser welding to 7-day aging cabinets.
- Live video tours — a scheduled walk-through with an English-speaking engineer, typically within the same week.
- Third-party inspection — SGS, TÜV and ITS inspectors welcome; we hand over line records and cell lot traceability.
- Sampling before scale — sample packs in 15–20 working days from spec sign-off; sample fees credited against the first order.
Inquiry Quality
Six Things That Speed Up Your Quote
Voltage
Platform and window — 12V / 24V / 36V LiFePO4, 48V (51.2V 16S), 60V or 72V (20S).
Capacity & energy
Target Ah and kWh — from 12V 100Ah drop-ins to 16-parallel rack systems at 81.92 kWh.
Envelope & mounting
Max dimensions and fixture — wall bracket, 19" rack rails, down-tube or Group 31 tray.
Communication
CAN / RS485 / Bluetooth and your inverter protocol — Deye, Victron, Growatt, SMA profiles on file.
Certification target
UN38.3 is the baseline; add CE, IEC 62133-2 or UL 1973 depending on your market entry.
Annual volume
Standard lines start at 10 units for pilots; fully custom builds from 200–500 pcs.
Missing a field? Send what you have — the first reply usually contains the two or three questions that actually matter for your application.
Before You Write
Four Questions Buyers Ask First
How fast will I get a quote?
Can I get samples before committing to volume?
Do you handle dangerous-goods export paperwork?
Can we audit the factory remotely?
Ready to Send a Spec?
One email to sales@ems-ess.com — voltage, capacity, application, annual volume — and an engineer starts the costing. Reply within 24 hours, proposal within 2 working days.
