I have had a lot of fun with my ele/ele with his focus on smash/lethal Def. I can try and post my build later, currently at 37.88% to smash/lethal and 35% to melee. Add in your armors, CJ, tough and weave. As long as you work in hasten, Energize (which has end reduce and regen added so slot for recharge and healing), and power sink and stamina, you shouldn't have endurance issues.
That's kept me in good shape with the combo of defense, resistance, knockdown and end drain.
Here's my build 
Look over this and see if you can find any major flaws. (took targeting drone because, well i wanted it and didint really need energy mastery) Ohh and I may replace the oblits in lightning field with sciroccos, it has more end reduction
Hero Plan by Mids' Hero Designer 1.601
http://www.cohplanner.com/
Click this DataLink to open the build!
Zap Efron4: Level 50 Science Scrapper
Primary Power Set: Electrical Melee
Secondary Power Set: Electric Armor
Power Pool: Leaping
Power Pool: Fitness
Power Pool: Fighting
Ancillary Pool: Weapon Mastery
Hero Profile:
Level 1: Havoc Punch
- (A) Kinetic Combat - Accuracy/Damage
- (42) Kinetic Combat - Damage/Endurance
- (43) Kinetic Combat - Damage/Recharge
- (43) Kinetic Combat - Damage/Endurance/Recharge
- (43) Mako's Bite - Accuracy/Damage
- (45) Mako's Bite - Damage/Recharge
- (A) Reactive Armor - Resistance
- (40) Reactive Armor - Resistance/Endurance
- (40) Reactive Armor - Resistance/Recharge
- (40) Reactive Armor - Resistance/Endurance/Recharge
- (48) Steadfast Protection - Resistance/+Def 3%
- (A) Obliteration - Damage
- (3) Obliteration - Accuracy/Recharge
- (3) Obliteration - Damage/Recharge
- (5) Obliteration - Accuracy/Damage/Recharge
- (5) Obliteration - Accuracy/Damage/Endurance/Recharge
- (7) Obliteration - Chance for Smashing Damage
- (A) Obliteration - Damage
- (46) Obliteration - Accuracy/Recharge
- (46) Obliteration - Damage/Recharge
- (46) Obliteration - Accuracy/Damage/Recharge
- (48) Obliteration - Accuracy/Damage/Endurance/Recharge
- (48) Obliteration - Chance for Smashing Damage
- (A) Reactive Armor - Resistance/Endurance
- (7) Reactive Armor - Resistance
- (37) Reactive Armor - Resistance/Recharge
- (37) Reactive Armor - Resistance/Endurance/Recharge
- (A) Obliteration - Damage
- (9) Obliteration - Accuracy/Recharge
- (9) Obliteration - Damage/Recharge
- (15) Obliteration - Accuracy/Damage/Recharge
- (17) Obliteration - Accuracy/Damage/Endurance/Recharge
- (17) Obliteration - Chance for Smashing Damage
- (A) Reactive Armor - Resistance
- (11) Reactive Armor - Resistance/Endurance
- (11) Reactive Armor - Resistance/Recharge
- (15) Reactive Armor - Resistance/Endurance/Recharge
- (A) Red Fortune - Defense/Endurance
- (13) Gift of the Ancients - Defense
- (13) Gift of the Ancients - Defense/Endurance
- (A) Jumping IO
- (A) Jumping IO
- (A) Numina's Convalescence - Heal
- (19) Numina's Convalescence - +Regeneration/+Recovery
- (19) Regenerative Tissue - +Regeneration
- (A) Efficacy Adaptor - EndMod/Accuracy
- (21) Efficacy Adaptor - EndMod
- (21) Efficacy Adaptor - EndMod/Endurance
- (A) Reactive Armor - Resistance
- (23) Reactive Armor - Resistance/Endurance
- (23) Reactive Armor - Resistance/Recharge
- (37) Reactive Armor - Resistance/Endurance/Recharge
- (A) Numina's Convalescence - Heal/Recharge
- (25) Miracle - Heal/Recharge
- (25) Doctored Wounds - Heal/Recharge
- (34) Harmonized Healing - Heal/Recharge
- (A) Recharge Reduction IO
- (27) Rectified Reticle - To Hit Buff/Recharge
- (27) Rectified Reticle - Increased Perception
- (A) Kinetic Combat - Accuracy/Damage
- (29) Kinetic Combat - Damage/Endurance
- (29) Kinetic Combat - Damage/Recharge
- (31) Kinetic Combat - Damage/Endurance/Recharge
- (31) Mako's Bite - Accuracy/Damage
- (31) Mako's Bite - Damage/Endurance
- (A) Run Speed IO
- (A) Obliteration - Damage
- (33) Obliteration - Accuracy/Recharge
- (33) Obliteration - Damage/Recharge
- (33) Obliteration - Accuracy/Damage/Recharge
- (34) Obliteration - Accuracy/Damage/Endurance/Recharge
- (34) Obliteration - Chance for Smashing Damage
- (A) Kinetic Combat - Accuracy/Damage
- (36) Kinetic Combat - Damage/Endurance
- (36) Kinetic Combat - Damage/Recharge
- (36) Kinetic Combat - Damage/Endurance/Recharge
- (A) Reactive Armor - Resistance
- (39) Reactive Armor - Resistance/Endurance
- (39) Reactive Armor - Resistance/Recharge
- (39) Reactive Armor - Resistance/Endurance/Recharge
- (A) Red Fortune - Defense
- (42) Gift of the Ancients - Defense
- (42) Gift of the Ancients - Defense/Endurance
- (A) Efficacy Adaptor - EndMod
- (45) Efficacy Adaptor - EndMod/Recharge
- (45) Efficacy Adaptor - EndMod/Endurance
- (A) Recharge Reduction IO
- (A) Rectified Reticle - To Hit Buff
- (50) Rectified Reticle - To Hit Buff/Recharge
- (50) Adjusted Targeting - To Hit Buff/Endurance
- (50) Adjusted Targeting - To Hit Buff
Level 1: Brawl
- (A) Empty
- (A) Empty
- (A) Empty
------------
Set Bonus Totals:
- 14% DamageBuff(Smashing)
- 14% DamageBuff(Lethal)
- 14% DamageBuff(Fire)
- 14% DamageBuff(Cold)
- 14% DamageBuff(Energy)
- 14% DamageBuff(Negative)
- 14% DamageBuff(Toxic)
- 14% DamageBuff(Psionic)
- 31.8% Defense(Smashing)
- 31.8% Defense(Lethal)
- 3% Defense(Fire)
- 3% Defense(Cold)
- 9.25% Defense(Energy)
- 9.25% Defense(Negative)
- 3% Defense(Psionic)
- 28.6% Defense(Melee)
- 6.13% Defense(Ranged)
- 3% Defense(AoE)
- 20% Enhancement(RechargeTime)
- 36% Enhancement(Accuracy)
- 90.4 HP (6.75%) HitPoints
- MezResist(Immobilize) 20.4%
- MezResist(Stun) 8.8%
- 20% Perception
- 7% (0.12 End/sec) Recovery
- 12% (0.67 HP/sec) Regeneration
Your build doesn't look too different then mine, but I sacrificed a little def for extra resistance, and hasten to speed up build up, LR, and Energize. Maybe switch to body mastery to take focus acc. and hasten then skip caltrops.
I have been messin with mids trying to make a PvE elec/elec scrapepr build. But even after playing mine on 50 for ages now, I still haven't worked out a solid build for him. Could someone help me please? I don't know what to build him for recharge/recovery/regen!?!?!? *frustrated*