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ElectricalAt your house

Battery Testing, Repair & Replacement

E-bike battery service is a measured health test of the pack, BMS, charger, and charge port that tells you whether lost range is recoverable through repair or genuinely needs a new battery — usually a $60 answer instead of an $800 guess.

Starting at
$59
Typical time
30 min–2 hr
Warranty
90 days on labor

$59 battery health test — waived with repair. Repairs from $125.

Makers quote 500 to 1,000 full charge cycles for a lithium pack; Diamant calls 500 to 700 standard, which for most riders is three to five years. But "my range got worse" has at least five causes and only one of them is a worn pack. Low tire pressure, a dragging brake rotor, a gummed-up chain, a cold-soaked battery, and a single weak cell group all look identical from the saddle.

I test capacity against the pack's rated watt-hours, check balance across cell groups, verify the BMS is not tripping early, load-test the charger, and inspect the charge port and battery mount contacts — which on coastal bikes in San Clemente and Dana Point corrode far faster than inland ones. Salt air is genuinely hard on charge ports and it is a repair, not a replacement.

Charge-port rebuilds, connector repairs, mount-contact cleaning, and BMS replacement I do at your house. Cell-level pack work happens on the bench, where it belongs — opening a lithium pack in a customer's garage is not something a careful technician does.

If you do need a new pack, I'll source an OEM or a properly tested and labeled replacement that is legal to sell in California under SB 1271 and install it properly. I won't sell you a gray-market pack, and I won't install one you bought from a marketplace listing with no certification marks.

An e-bike battery pack out of the bike on the grass, next to its rider

Trip fee for this visit

  • Zone 1 — San Clemente +FREE
  • Zone 2 — Ladera Ranch +$35
  • Zone 3 — Irvine +$65
Check your zone

Symptom → cause

What the bike is doing, and what it usually means

Symptoms and their likely causes for Battery Testing, Repair & Replacement
What you noticeWhat it usually is
Range is half what it wasCapacity fade, weak cell group, or non-battery drag — tested in order
Charger light stays green, bike won't chargeCharge port pins, charger output, or BMS charge FET
Battery shows full, dies in a mileSeverely imbalanced cell group holding false voltage
Pack won't seat or cuts out over bumpsCorroded or spread mount contacts (very common on coastal bikes)
Pack is warm, swollen, or smellsSTOP RIDING AND STOP CHARGING — call me before doing anything else

Prices

Electrical Repairs

Labor shown. Parts at cost plus 15%, quoted before I order anything.

Electrical Repairs price list
Charge port repair or replacement$125–$195
Battery mount contact service$75
BMS replacement+ part$145
Battery pack cell-level repairBench work — pickup and return includedfrom $225
Battery replacement install+ pack; OEM or UL-certified only$65
Controller replacement+ part$95
Display replacement+ part$75
Throttle replacement+ part$55
PAS / cadence sensor + magnet ring+ part$75
Torque sensor service & calibration+ part if needed$125
Speed sensor + magnet alignment$45
Brake cut-off switch repair+ part$55
Connector rebuild (crimp, shrink, seal)Per connector, $95 for a full harness pass$45
Wiring harness repair$95–$185
Hub motor remove & reinstall$145
Mid-drive remove & reinstall$185
Geared hub motor rebuild+ gear setfrom $185
Hub motor replacement+ motor$195 labor
Every other price

Book service

Need battery service?

Takes a minute. You'll hear back within 30 minutes during business hours — and if it's faster to just call, call.

  • Free quote before any work starts
  • No trip fee in San Clemente, Dana Point or San Juan Cap
  • 90 days on all labor
  • Nothing gets added to the bill without a call first

I'll text first unless you'd rather I call.

Tells me your zone and trip fee.

The more specific, the more likely I can quote it before I show up.

No spam, no list, no reselling your info — see the privacy note. Prefer to skip the form? Text me a photo at (949) 891-5278.

FAQ

Before you book

Do you actually work on batteries, motors, and controllers — or just the mechanical stuff?

All of it. This is the main reason to call me instead of a general mobile bike mechanic. Most mobile bike services in Orange County explicitly decline battery, motor, throttle, and controller work, which means a bike with an electrical fault has nowhere local to go. I diagnose and repair charge ports, battery management systems, controllers, displays, throttles, cadence and torque sensors, brake cut-off switches, wiring harnesses, and hub and mid-drive motors — plus everything mechanical.

What brands do you work on?

Every brand. That includes direct-to-consumer bikes with no local dealer — Rad Power, Aventon, Lectric, Ride1Up, Velotric, Heybike, Himiway, Juiced, Super73, Segway — and dealer brands like Specialized Turbo, Trek, Giant, Cannondale, Electra, Gazelle, Tern, Pedego, Blix, Magnum, and Riese & Müller. On the motor side I work on Bosch, Shimano STEPS, Brose, Yamaha, Bafang, Fazua, Mahle, and generic hub systems. One honest caveat: Bosch and some Shimano systems lock firmware and certain diagnostics to authorized dealers. I can do every mechanical and electrical repair on those bikes and I'll tell you upfront on the rare occasion something has to go through a dealer.

My range dropped a lot. Do I need a new battery?

Probably not, and this is the most expensive assumption in e-bike ownership. Lost range has at least five common causes and only one of them is a worn battery: low tire pressure, a dragging brake rotor, a worn or dry chain, colder weather, corroded battery mount contacts, and actual capacity fade all produce the identical symptom. A $59 battery health test measures capacity against the pack's rated watt-hours and checks balance across cell groups, which tells you definitively which it is. That fee is waived if you have me do the repair. A new pack is $400 to $1,200 — it's worth $59 to find out whether you need one.

Is there a warranty on the work?

90 days on all labor. If something I worked on isn't right afterward, I come back and fix it — no trip fee, no argument, in any zone. Parts carry whatever warranty the manufacturer provides and I'll handle the claim paperwork with the brand for you.

What can't you do at my house?

Three things go to the bench rather than the driveway: cell-level battery pack repair (opening a lithium pack in a customer's garage isn't something a careful technician does), full wheel rebuilds and rim replacement, and internal motor rebuilds that need a press. For all three I pick the part or the bike up and bring it back, usually within two to four days. Everything else — including motor removal and reinstall, controller and display replacement, harness repair, brake bleeds, and full tune-ups — happens where your bike is.

Do you need power or water at my house?

No. The van carries its own power, lighting, compressed air, and water. All I need is a flat spot roughly the size of a parking space, within reason of where the bike is. Driveway, street, garage, courtyard, parking lot, or a turnout on a Laguna hillside all work fine.

Do I need to be home the whole time?

Only at the start and the end. I need five minutes with you at the beginning to understand what the bike is doing and to confirm the quote, and five minutes at the end to hand it back and show you what changed. In between you can go to work, take a call, or leave entirely.

My display is showing an error code. What does it mean?

It depends on the system, because every maker numbers its own faults: 21 is a speed sensor fault on a Bafang display but abnormal current on a Rad, and Shimano's codes start with W or E. The free error code lookup has the makers' own tables for Bafang, Bosch, Shimano STEPS, Rad Power Bikes, KT and Segway-Ninebot, with the maker's first step for each. If a code points at the battery or charger, stop charging and riding until it's checked.

Something not answered here? Just ask — I’d rather talk it through than have you guess.

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