Ewwwww... SLA..

[Ypedal]

It's been a while since i touched lead bricks..... horrible reminder of why i dislike them so much... the WEIGHT. holy smokes.





As much as i hate to admit it, there is a time and place for lead.. ... These are all new, fresh bricks, over the next few weeks i'll be torturing them..

I think i'm going to have to start making custom rear racks...

 

[SamTexas]

Torturing? Sounds good. I wonder if you could do me a favor: On your best (and possibly highest capacity brick): Discharge it at 0.5C (from full charged) to 10.0V (underload) and report the Ah. I would also need: Weight, advertised capacity, dimension, and age if known. I did this a few times before, but lost my data.

TIA even if you don't do it.

 

[migueralliart]

SLA ...

sooo long ago .

 

[Ypedal]

yeah, i got 3 each of 8ah, 10ah and 12ah

discharge at 0.5c should be fairly easy, i have to see if i can get my 3010b to talk to my laptop again... that's also been a while since i've mess with it...

First step, charge all 12v bricks by themselves to eaqualize and *cough ballance them .. then cycle at 36v a few times before starting data logging. Fun times.

 

[SamTexas]

Great. Anyone cares to guess what the capacity would be under that discharge condition? IIRC, it was 60 to 65% of the claimed capacity.

 

[Ypedal]

thes are intended for a 15 amp application.. to the 10ah will need to test at 1.5C etc. will be interesting to see the difference between the 3 cpacities.

 

[Takemehome]

Very nice door stoppers you got there. :lol:

 

[DAND214]

One question, WHY?
Sorry, two.
Have you been drinking alraedy?

Dan

 

[Gregb]

I have one in my car......

 

[Holocene]

Great. Anyone cares to guess what the capacity would be under that discharge condition? IIRC, it was 60 to 65% of the claimed capacity.

Hi SamTexas,

Yup, agreed. I got 8.0 AHrs @ 0.5 C on newly-conditioned 12 AHr SLA, so 2/3rds of their 20-Hr discharge rated energy. That's running them at a steady 6 Amps load, limited by my Cycle Analyst (excellent to avoid spikes!). The Peukert exponent worked out to 1.17 on these batts when new. BTW, 8.33 lbs each, 25 lbs for 3 to make 36 volts.

6 Amps at 36 volts is only about 200 Watts assist, so I have to pedal occasionally to maintain 20 mph (32 kph). But still that's twice my pedal input, so useful for hour long trips

 

[dogman dan]

Ewwww indeed. Looks like they would be useful if you had a solar panel or two, run a charger or as an emergency power setup. Lug em around? Ugh.

Presumably they were too cheap to pass up, or even free?

 

[SamTexas]

Great. Anyone cares to guess what the capacity would be under that discharge condition? IIRC, it was 60 to 65% of the claimed capacity.

Hi SamTexas,

Yup, agreed. I got 8.0 AHrs @ 0.5 C on newly-conditioned 12 AHr SLA, so 2/3rds of their 20-Hr discharge rated energy. That's running them at a steady 6 Amps load, limited by my Cycle Analyst (excellent to avoid spikes!). The Peukert exponent worked out to 1.17 on these batts when new. BTW, 8.33 lbs each, 25 lbs for 3 to make 36 volts.

6 Amps at 36 volts is only about 200 Watts assist, so I have to pedal occasionally to maintain 20 mph (32 kph). But still that's twice my pedal input, so useful for hour long trips

Did you remember the cutoff voltage? Under load of course.

Anyway, 200W assist is quite significant. On mine it's about 8Wh/mi at a moving average of 18mph.

 

[davec]

reminds me of my first ebike using a daymak kit
ahh memories (http://www.daymak.com/ebikeinabox/main.html)
my batt;s looked just like that- 2 of them in series for 24v - (thinks 12-10ahmaybe?)
the weight wasn't too bad but the performance was horrible-
12km trip to work i got about 5km until the peukert effect kicked...... (majour sag and i was barely able to maintain 20/km hr after that)
i always followed the sla rules kept the cells charged @ work and the min i got home- i honestly barely got 80 cycles of life out of it (2months use) until it was totally useless-
SLA Never again- total waste of money (toxic,heavy, low life cycle, peukert effect) total FAIL
i suppose cars still use them because they're cheap and last longer due to lower DOD compared to ebikes

 

[Ypedal]

dogman, believe it or not.. i actually paid for these... all new.

so far. the 8ah bricks took 650, 103 and 77 mah as per the icharger... working on the 10's now.

the Why is simple, money.

Some people just cannot afford lithium, selling a 500$ kit with a 600$ battery is a tough pill for newbs to swallow.... lead = 150$

for a 350w kit it almost makes sense... oh man.. i feel queasy..

 

[Lessss]

Batteries are still way over priced. The prices we currently pay for lead are what we should be paying for lithium.

 

[Stevil_Knevil]

I like SLA batts..

..2 in series to power my 3010 iCharger while balance charging LiPO packs

 

[dogman dan]

Ahh, for others.

Strangely, lead can still work excellently for some. It's just not ideal for people who ride much further than 5 miles, at speed above 20mph. But if you ride 15 mph, you can do ok for short commutes.

I just never have much in the way of short trips. Flea market and dollar store are 2 miles away, not too bad. Grocery is 8 miles, and down a 1000 vertical foot hill. Just try to get back on lead.

 

[bluegoatwoods]

"Just try to get back on lead"

I feel your pain, dogman. My climb, coming home, is only a couple hundred feet. And I do it with SLAs. On a good day, they're strong enough for the job. On a bad day, though, it's up to me to be strong.

All the same I am one of those who gets along with lead well enough. I just don't ride very fast. About as fast as I ride my regular old pedal bike. And now that I'm in my 50's, that averages out to somewhere around 10 mph over my 6 mile commute.

It's good enough for that.

 

[SHARKBITEATTACK]

They seem to work ok in golf carts still

 

[dogman dan]

So would bikes, if they could carry 200 ah of it. But It's difficult to carry more than 20 ah of lead on bikes.

I don't have the numbers, but I suspect typical golf cart loads are much lower c rates than bikes. I have lots of experience with golf carts, and expected about the same when I got a lead bike. Instead it was Hello peukerts effect. At one point I did carry 40ah of lead on a bike, and the motor/battery performance was a lot better, but it handled bad.

 

[Holocene]

lead = 150$

Hi Ypedal,

Ouch, $150 for 3 x 12v12Ahr SLA? I get mine from Battery World in Edmonton @ $32 each (the Manager smiles when she sees me).

I also noticed last Summer that Princess Auto had new 12-12 SLAs on sale for $20 each (just gotta watch the bi-weekly sales flyer).

Or, if you're real lucky/clever, find a friend who works in IT. We're constantly cycling UPS batteries, and giving away replaced ones. Most IT shops replace SLAs after 1 year, regardless of condition. Unless the mains power in Moncton is particularly bad, the UPS might not have put that many cycles on the SLAs. So it is really hard to beat FREE, even if you only get 1 season out of the batts before recycling.

I'd say the most expensive part is a new charger. But if you can convince them to invest in a decent 150 watt charger with multiple chemistry support, then that's a capital investment rather than an expense. It should be useful for a decade and 3 to 5 sets of batts. And save what, maybe $6,000 on gas? Even if they're purchasing new batts every 2 years, @ $32 ea + HST, that's only $540 over those10 years, or $54 a year. That's like buying 1 tank of gas a year! 8)

Let us know how your Customer fares. This will be interesting to follow.

 

[Holocene]

Did you remember the cutoff voltage? Under load of course.

Anyway, 200W assist is quite significant. On mine it's about 8Wh/mi at a moving average of 18mph.

Hi SamTexas,

I set LVC on my Cycle Analyst to 33 volts for this test. When the CA sees that the pack can no longer stay above LVC with the 6 amp load (also selectable), it starts backing off the throttle to keep the pack at LVC. That's the endpoint for my test, you just have to leave the AMPS display on the CA while riding.

Also, there was damn little energy from 34.5 down to 33 volts. So these days, I set LVC to 36 v, and set a current limit of 8 amps. That gives me a good cruise speed with minimal pedaling, I need to assist on hills and take-off, but I get a nice soft landing when the pack starts to weaken.

When I see the CA starting to drop load at LVC, I know it's time to find a plugin but I still have some useful power. And this way I never over-discharge the SLAs, and i keep a little sumtin' in my back pocket 8)

 

[Tommy L]

I like SLA batts..

..2 in series to power my 3010 iCharger while balance charging LiPO packs

Priceless! I've been known to do the same! :wink:

I have 2 lead AGM deep cycles I keep charged up for power outages. Keeps laptop (for ES access), Modem, and router +
charge my A123's

These two AGM's where on my first build with Inverter,geared 10amp Rigid drill, and light dimmer for throttle.
Hard Core! This beast had great torque! And man.......she was top heavy! lol

Tommy L sends......

 

[SamTexas]

Did you remember the cutoff voltage? Under load of course.

Anyway, 200W assist is quite significant. On mine it's about 8Wh/mi at a moving average of 18mph.

Hi SamTexas,

I set LVC on my Cycle Analyst to 33 volts for this test. When the CA sees that the pack can no longer stay above LVC with the 6 amp load (also selectable), it starts backing off the throttle to keep the pack at LVC. That's the endpoint for my test, you just have to leave the AMPS display on the CA while riding.

That's great. 8 out of 12Ah at 0.5C is more than I expected. Sounds like you got some of the better SLAs.

 

[Ypedal]

wow tommy, that is one hell of a lead sled... ouf.

cycle no.1 on the 8ah bricks..



I'm getting these from the local " Interstate Battery " located near my house, i quoted a 36v 12ah SLA " pack " as aprox 150$.. the bricks are 30 something but add a charger and connectors, wires, fuse, time, etc... :wink:

There are 2 vendors in town, the other is a " Battery House " but the head cheese there is not as friendly or outgoing.. and their prices are even higher.

I'm willing to pay more for better bricks, idealy as " fresh " as possible.... the 10ah bricks i got from the box in post no.1 are def older than the other bricks... one of them took 4ah charge