new ebike!!

[lovemysan]

I got the batteries in last night. One of the brake light switches was broken causing a no start on the wheel motor. Once I figured that out it was peachy. This morning I charged the batteries. I'm using a 24v scooter charger. Specs are 29v max charge@2.5amp then drop to 28v float. I checked the batteries periodically. The plumber arrived and I left them unattended. When I returned after 1 hour there was a slight sizzingling sound inside the batts. Voltage was 29.6. I pulled the plug. They seem okay but I think I hurt them. I'm pretty sure this charger is junk. I installed and made a hilly/windy 4 mile round trip in 25 minutes. At this point the bike weighs about 80lbs. Its a beast to pedal. It handles decent. My legs are very sore after even a short ride at 10mph average. I started with 13.1volts after the 4 miles and 15-20minutes testing I have 12.2volts per cell. I'm not sure what the lowest safe level of charge is. The 25-49% light was on. I need to get a DWM to check for voltage sag. I might also mention that I weigh 230lbs+. My current range with light to moderate pedaling is 6 miles. I'm glad that I didn't pay $1200 for one of these, I'd be disappointed. The weight of the SLA's seriously negate the assist provided by the motor. After 8 miles this bike would be a paperweight.

[MetroMPG]

Originally Posted by lovemysan

I'm not sure what the lowest safe level of charge is. The 25-49% light was on. I need to get a DWM to check for voltage sag.

I'd definitely recommend a DVM or build/buy an equivalent LED meter.

Not sure if sealed battery chemistry is the same as flooded (doubt it), but the safe lower limit under load for a floodie is 1.75v per cell, or 10.5v per 12v battery.

Below that, you run the risk of reversing a cell and ruining the battery.

Generally people don't recommend drawing the floodies much below 50% for maximum cycle life. And avoid letting the batteries sit partially discharged.

Speaking of which that reminds me it's time to top up the ForkenSwift's second pack (sitting in the garage). I do it once a month.

[lovemysan]

So what would you recommend as minimum voltage, 11v? I'm looking a 1.5 amp 3 stage charger from soniel. I've found it for around $30.

http://www.batterystuff.com/battery-...Son2403SR.html

Do you think 1.5amps is enough or should I go 2 or 4. My current charger states 28.8 volts 2.5amps, but it literally cooks the batts, I think its damaged.

[MetroMPG]

Voltage - resting, or under load?

I've heard the Soneils are good chargers. Can't beat a 3-stage purpose made SLA charger. Also - you know the trick about hitting up alarm companies for used batts? I think they're mostly 14ah.

[lovemysan]

Originally Posted by MetroMPG

Voltage - resting, or under load?

I've heard the Soneils are good chargers. Can't beat a 3-stage purpose made SLA charger. Also - you know the trick about hitting up alarm companies for used batts? I think they're mostly 14ah.

Both!

I got some emergency light batteries before that turned out to be pretty soft. Currently I'm getting 12v 12ah for $20 each 12v 7.2ah for $12 and 6v 10ah for $10. I'm pretty happy with those prices especially considering there new. My only concern would be they might be partially sulfated but they had 12.5v when I unboxed them.

[lovemysan]

Hacktofabulous battery box mod

[MetroMPG]

Well under load, I'd say keep them above 1.75v/cell. For resting voltage - ie. depth of discharge after use, if we say 12.65 = Full and 11.7 = empty, the ideal situation for cycle life is to go to around 50% depth of discharge. (I've also read that somewhere between 50-80% is OK.)

[lovemysan]

I've not pulled the batts below 12.2v yet. I'm going to need to study this properly before going any further. I need to get everything properly installed and shrink wrapped. I need to install a distribution block, mount the e-stop better, instrumentation, etc. I'll upload a video soon!