The eZip Trailz is the "budget " eBike.
Annual-occasional sales drop the price into the mid $300 range, (~$350) See - Continuous price tracking
OEM battery pack is a 24V 10Ah SLA ... providing limited range and durability.
450w motor is a proven durable component, underutilized, in my opinion.
Top speed is typically in the 15-16mph range ...
Sadly, inadequate for me, not even attaining the "legal" (USA) 20mph limit.
My first mod was upgrading to 36V with 10Ah SLA.
2008 OEM controller provided 24-36V compatibility.
This provided a 50% speed and torque increase ... now were talkin'!
Problem was that WOT was liable to "burn up" the motor.
Many predecessors told sad tails of "smoke n burn".
Rather than going the extreme of cooling mods, drillings, fans etc., I tended towards manual moderation.
Avoiding WOT, especially at low rpms, where efficiency is minimal and waste heat can run rampant!
Simply pedal assisting getting up to efficient speed and reducing throttle when efficiency is suffering.
2008 eZip Mountain Trailz @ ~4000 37V Li-ion miles!
When I built recycled laptop batteries into Li-ion battery packs their limited output, almost automatically, limited-moderated the damaging high amp drains.
After mid 2008-2009 the eZips controller was "upgraded" to a HVC that no longer allowed 36V battery use.
After a bit of trial and error I began building 25.9V Li-ion batteries that were compatible.
The ~8% voltage increase produced a noticeable improvement in speed and power, over the oem 24V SLA.
Speed was still "lacking" so I delved into multiple re-gearing projects, settling on 2 mods that allowed 20 mph capability. See - Re-gearing the eZips- Simple Mods!
Yes ... I "experimented" with higher speeds.
Initially I limited myself to the oem controllers.
I did "pump up" one of my eZips to 36V using an eZip scooter 36V controller ... only 25A, so the possible heat damage was moderated.
Unfortunately, most easily available controllers are designed for SLA batteries, in my opinion, the LVC is too low for Li-ions of the same rated Volts.
But, a 36V SLA controller works nicely with a 33.3V Li-ion, similar with 48V SLA controller for 44.4V Li-ion etc.
Sadly, one of my latest prototypes has no "compatible" controller and is even difficult to find a dedicated charger for.
In the eZip OEM battery case, I can shoehorn in 31.2Ah of 29.6V cells.
This should give me a robust ~20mph, voltage pumped up and no need for a torque reducing re-gearing.
(~24% torque increase, without the 20% torque reduction from re-gearing = nearly a 150% torque output , over 25.9V + 16T mod!)
Operating range does not fall nicely into the operating voltage of any controller, that I have found.
I have found multi-compatible controllers, 20V -72V compatible at 25A continuous an 30A cut-off. See -
Charging-balancing seems designed for the iMax B8, though at a 3A recommended charge rate, seem painfully inadequate as a primary charge method. 33.6V peak charge seems better supplied by a S-350-36V Meanwell with 10A output. (I tend to limit recycled Li-ion charging to <.5C - typical laptop charging rate. )
I normally Bulk charge, with the occasional "balance"
I made myself a chart showing the relative peak motor output from various voltage inputs.
3rd column is the Li-ion packs that I have tried, in eZip oem cases.
eZip-iZip-Currie 450w external gear motor (MY1018Z and XYD-16)
22.2V = 415w - 6s16p
24.0V = 450w - 2-12V SLA Comparison
25.9V = 485w -7s12p
29.6V = 555w - 8s12p
33.3V = 625w - 9s
36.0V = 675w - 3 - 12V SLA
- Toolbox Pack
37.0V = 695w - 10s8p
40.7V = 765w - 11s
44.4V = 832w - 12s8p
48.0V = 900w -
48.1V = 900w - 13s
51.8V = 970w - 14s
55.5V = 1040w - 15s
See - Homemade Battery Packs - Index
Also - eZip-iZip-Currie Re-gearing Mods