FAQ
Frequently Asked Questions
Your guide to shopping, compatibility, and safe DIY battery building with RenewSpark.
Ordering & Shipping
How fast do you ship?
Most in-stock items are processed within 1–2 business days. You’ll receive an email with tracking as soon as your order ships.
Where do you ship from?
Orders ship from our facility in Southern California. Domestic U.S. orders typically arrive in 3–5 business days depending on distance and carrier speed.
Do you offer returns or exchanges?
Yes. Unused items in original packaging can be returned within 30 days of delivery. Cells or electronic components that have been welded, soldered, or altered are not eligible, and nickel cut from a roll cannot be returned. Read our full returns policy.
Do you rebuild batteries for customers?
No. RenewSpark supplies parts only — we don’t build, rebuild, or repair packs, and we can’t accept batteries by mail. What we do instead is stock every component you need and publish step-by-step build guides so you can do it yourself.
Product Compatibility
Do your rebuild kits fit major power tool brands?
Yes — our rebuild kits include an OEM-style housing, BMS, nickel and hardware for popular platforms including DeWalt, Milwaukee, Makita, Ryobi, RIDGID and Bosch. Always confirm your exact model in the product description before purchase.
How do I choose the right voltage and capacity?
Voltage is determined by the number of series cells (S). Capacity and current handling come from parallel cells (P). Check our Getting Started Guide for an easy breakdown.
Are your connectors standard?
Yes — we carry XT30, XT60, XT90, JST-XH and JST-PH, plus DC barrel connectors, used across e-bikes, scooters, and tool packs. Our connector guide explains which to pick.
Cells & Materials
Are your lithium-ion cells genuine?
Absolutely. We stock authentic cells from trusted manufacturers including BAK, Molicel and Samsung, with consistent voltage and internal resistance verified on arrival. Browse cells.
What’s the best cell for power tools or e-bikes?
Power tools typically perform best with high-discharge cells (20–30A continuous). E-bikes often benefit from higher-capacity cells with moderate discharge. Our power tool cell guide lists what each brand and model uses.
Can I put 21700 cells in an 18650 pack?
No. A 21700 is 3 mm wider and 5 mm longer than an 18650, so the formats are not interchangeable. Rebuild in whatever format your pack was designed around — see our 21700 vs 18650 comparison.
BMS & Protection
How do I pick the right BMS?
Match the BMS to your pack’s series count (S) and select a continuous current rating above your expected draw. Our BMS sizing guide walks through it. Shop BMS & Protection.
Do you offer balance and non-balance options?
Yes — balanced BMS models keep each series group even for improved safety and longevity. Non-balance options are available for simple or low-current builds.
Nickel, Wiring & Insulation
Is your nickel strip pure?
Yes. Our nickel strips are made from pure nickel (not plated), ensuring reliable conductivity and corrosion resistance. Available pre-cut or in rolls — our sizing guide helps you pick the right thickness and width.
Do you sell tools for assembly?
We stock the consumables — fish-paper insulator rings and sheet, Kapton tape, nickel and copper strip, connectors and heat-shrink. We do not currently sell spot welders, soldering stations, or internal-resistance testers; our build guides name the ones we use so you can source them wherever you prefer.
Safety
Always use proper tools, PPE, and knowledge when working with lithium-ion cells. Confirm polarity before welding or soldering, use insulation materials like fish-paper and Kapton tape, and always include a proper BMS.
For questions about parts or build safety, contact us before proceeding.
