ES was a welcome relief from MTBR because every "e" related issue there became a pissing contest. Looks the same here for an identical reason: individuals fail to respond to the inquiry and go off on their own inane direction. Years ago my kids had a blast on lead-acid powered vehicles (mostly 12V AIR) that provided eight or so miles per charge, and the batteries lasted at least a year even though used almost every day.
Lead acid anyone?
- Thread starter Archer321
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Voltron
1 MW
So much lead acid misinformation in one place! Some lead acid updates from the last decade.... While never matching lithiums power to weight, AGM (absorbed glass mat) lead acids have solved all the other complaints about lead. They can sit on a shelf for a year without self discharging or sulphating, there's no plate shorting from buildup between or under the plates, they can be used upside down or on their side, and they don't emit hydrogen during charging, unless there is a giant overcharge that pops the safety valve.
Chalo
100 TW
fechter said:
That's what I used in my first two e-bikes. [Edit: Actually, they were Hawker Odyssey.]
Then I went back to regular pedal bikes for several years, because I decided that was better. I'd do it again, if lead batteries were my best electric storage option.
An unscrupulous UPS vendor can get you to waste money on ANY battery. You can cook a LiFePO4 pack as easily as an AGM battery.flippy said:
We've been using AGM in our UPSes for 30 years now. They get replaced regularly after 20 years. No problems. No "cooking."
spinningmagnets said:
In a sealed battery, the hydrogen generated by electrolysis gets recombined and turns back into water. The only time hydrogen would escape is if you did a massively high overcharge and the vent opened. In a flooded battery, some hydrogen might escape through the vent but the amount of hydrogen generated is normally very small unless you charge at too high of a voltage.
We have thousands of lead acid battery powered devices in the hospital. I've probably seen just about every possible failure mode.
About the worst one was in a large UPS that used 6 batteries in series (72v). It was probably left unplugged long enough for one of the cells to sulfate, expand, and short internally. This placed excessive charging voltage on the remaining cells and overheated enough to melt the case and cause a small fire. It made lots of stinky smoke, but was confined by the housing.
flippy
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because SLA contains sulfuric acid (and a lot of it in industrial UPS systems) its classified as class 8 UN1830 once you get beyond 1 ton of batteries. you need a special licence (called ADR for commerical drivers) to move more then a few hundred pounds in europe. the potential fire and gas emitting problems make it a problem because UPS systems keep SLA on a very high float charge that boils them dry basically. for this reason it also is illegal to have SLA batteries inside the passenger compartiment of a (racing) car. a racing car that is mentioned here would not even be allowed on a racetrack in europe unless the battery compartiment is separated from the drivers side.Sunder said:
that is a cute little one fechter, i guess APC aftermarket considering the brand and lack of double side foam tape?
imagine what would happen with having large racks of 220Ah batteries that weigh 60kg each...
Yeah, lead acid batteries have been around for years and still quite usable. However, I think lithium is the future. Too expensive for me to switch to in my golf cart quite yet. Anyway, this article helped me out when looking at the various differences. Primarily applicable to the golf cart class of units but still may help some of you. https:// golfcartresource.com/differences-between-lead-acid-sealed-and-lithium-batteries/
dogman dan
1 PW
For bikes, weight gets important. Lead generally affects the bike too much, if nothing else, making it need a different kick stand, and definitely hard to put on a bus rack, or get it up some steps to the house.
But there are folks for whom lead is still a good choice. AGMs best, but SLA can still work for specific limits.
Generally this is somebody who is old, or otherwise hardly able to pedal, or even balance a regular bike. They choose an adult trike, and then you can easily put 30 pounds of lead in the basket. But the trip distance still needs to be short. I never suggest 20 ah lead to anybody who will do more than 4 mile round trips, which will be about 50% discharge once the battery is no longer new.
For this specific case, lead is about half the cost. the person has zero need for 20 miles range. and it won't burn the house down charging.
But even after my house on fire, I'm not running lead on my bikes. Just not letting lithium into the garage. And no desire either, to make my RV house battery lithium.
But there are folks for whom lead is still a good choice. AGMs best, but SLA can still work for specific limits.
Generally this is somebody who is old, or otherwise hardly able to pedal, or even balance a regular bike. They choose an adult trike, and then you can easily put 30 pounds of lead in the basket. But the trip distance still needs to be short. I never suggest 20 ah lead to anybody who will do more than 4 mile round trips, which will be about 50% discharge once the battery is no longer new.
For this specific case, lead is about half the cost. the person has zero need for 20 miles range. and it won't burn the house down charging.
But even after my house on fire, I'm not running lead on my bikes. Just not letting lithium into the garage. And no desire either, to make my RV house battery lithium.
dogman dan
1 PW
Definitely still the thing for off grid. For some strange reason, I don't want a lithium battery in the RV.
When my RV is out off the grid, it runs on two deep cycle lead batteries, with partial charging from some tiny solar panels. Sunny day, I need only run my generator in the morning, to catch up with what the heater fan used at dawn. Or if I really want to use the microwave or charge an e bike. After that the panels keep up all day with the small load caused by the board in the gas fridge, the board in the water heater, any lights I use, the tv etc.
When my RV is out off the grid, it runs on two deep cycle lead batteries, with partial charging from some tiny solar panels. Sunny day, I need only run my generator in the morning, to catch up with what the heater fan used at dawn. Or if I really want to use the microwave or charge an e bike. After that the panels keep up all day with the small load caused by the board in the gas fridge, the board in the water heater, any lights I use, the tv etc.
Sealed lead acid batteries are great for mobility / disability scooters. That's because the extra weight is an advantage. By putting the heavy SLA batteries low in the scooter it lowers the centre of gravity and stops the scooter falling over and injuring the rider. Range isn't an issue either 24v 50AH SLA is good for 50 miles at 4 to 8 mph.
e-beach
10 MW
One summer a long time ago I heard a muffled pop and I looked across the street and saw my neighbor Henry running into his house. The next day, I asked him what had happened and he told me was charging his car battery it exploded spraying acid on his head, face and front of his shirt and he had run into the house to douse himself in the shower. Fortunately he had no serious burns.spinningmagnets said:
It is rare, but a lead-acid battery can explode with enough hydrogen build-up.
999zip999
100 TW
You must take the caps off to recharge a dead battery sla. They can explode if one cell is shorted and makes hydrogen gas. That's why if you see one cell bubbling away unplug.
I'm still on lead acid. It sucks but the total cost to switch to lithium is still too much. I'm about to buy new sla's again as I'm pedaling too much. I get about 2 years out of the cheap ones. The higher quality sla's cost too much now so I use the cheap ones and they don't last as long.
Tryker
1 mW
Archer321 said:
My son and I were avid participants in the Oregon/Washington Electrathon and are now planning on reentering. I know this is off topic...sort of...but I want to connect on this level as well...expecially if in our region. I also use SLA for my ezip 750 scooter and am looking for lead battery technology as well.
Tryker said:
Well let me be the first to welcome you back to Electrathon! You planning on running 24v or 36? Or something else? I have always run 36v and I find I can buy three 35ah batteries cheaper than two Optimas and in my corner of the country (Florida) I have always finished in the top three overall with that setup.
As I mentioned before, the victron super-cycle batteries look good on paper but they are twice the price of the Powersonics I'm currently running. So I doubt I'll ever try them. They're hard to find too.
When you reach a decision about what batteries you're going to use, post an update.
You might also consider going on the Electrathon America forum and posting pics of your car. We always like fresh faces over there.
Good luck and welcome back!
Tryker
1 mW
The lad found 4 batteries so we could run 48 volt. Won the student division at Portland International Raceway finals with a win in the long track, 2nd in short track (wrong gear darn it), and blew all away in the sprint/drags for a dominant win (including adult division). Ran with a Lynch motor. The web"master" had some sons in the events we attended over two years and lo and behold...tons of pictures of his kids' cars. What motor are folks using these days? Anyone tried an ebike motor setup for ecars?
Tryker
1 mW
Archer321 said:
Ours is the blue with yellow and red and a wooden "hull" thanks to some experience with boat building at 1:45 on this clip. https://www.youtube.com/watch?v=qGDdAohTgLQ.
Its my understanding that cell-tower backups in my region still use huge 6V L/A packs, so large that they can only be moved by a forklift, configured for 48V.
Maybe the discussion would be more relevant if we agreed that stationary applications and vehicles have two different spec requirements.
I'm building a 12V suitcase pack out of 2.4V LTO cells as an experiment. It is possible to reach 13V with 5S, but I am using 6S so I can also use various inputs with no fear of an overcharge, and no BMS. I may be giving up a little bit of my potential run-time, but storing LTO at 80% as the full charge appears to provide many years and many thousands of cycles of life.
The low energy-density of LTO compared to Li-NCA / Li-NCM means you wont likely see it on powerboards, bicycles, or motorcycles, but these cells are designed for a hybrid city bus. Since the bus is a hybrid, it doesn't need a huge pack. The features of note are that it appears to have very good cold weather performance, and it has one of the longest life-cycles of any chemistry.
When it comes to the potential of a fire...lead-acid, LiFePO4 and LTO are at the top of the "safest" list, and the possible failure modes simply "brick" the pack...
LTO abuse testing video
https://youtu.be/XsrRDZxEFQE?t=16
[youtube]XsrRDZxEFQE[/youtube]
Maybe the discussion would be more relevant if we agreed that stationary applications and vehicles have two different spec requirements.
I'm building a 12V suitcase pack out of 2.4V LTO cells as an experiment. It is possible to reach 13V with 5S, but I am using 6S so I can also use various inputs with no fear of an overcharge, and no BMS. I may be giving up a little bit of my potential run-time, but storing LTO at 80% as the full charge appears to provide many years and many thousands of cycles of life.
The low energy-density of LTO compared to Li-NCA / Li-NCM means you wont likely see it on powerboards, bicycles, or motorcycles, but these cells are designed for a hybrid city bus. Since the bus is a hybrid, it doesn't need a huge pack. The features of note are that it appears to have very good cold weather performance, and it has one of the longest life-cycles of any chemistry.
When it comes to the potential of a fire...lead-acid, LiFePO4 and LTO are at the top of the "safest" list, and the possible failure modes simply "brick" the pack...
LTO abuse testing video
https://youtu.be/XsrRDZxEFQE?t=16
[youtube]XsrRDZxEFQE[/youtube]
Tryker said:
The dominant car in my area runs a crystalyte hub motor and a lithium pack. Hub motors are still in the minority and that car is one of the only ones running well with one. There are still plenty of Etek motors in use but they are getting harder to find. Will you be running that same car or building a new one?
One time I read about putting Epsom salt and water in a worn sla battery. I tried it and it didn't do anything. It was suppose to make the sla like new again or at least better. I saw a video on it. Didn't work for me. I guess it's a just a myth. I later read about a chemist talking about it and I don't remember exactly what he said but it something about the lead plates wouldn't take the salt.
D-Man said:
I've seen some other additives like this stuff:
https://www.jbtoolsales.com/charge-...F4dfDQUY0M3Ase-7rBfWN68b5C6qc0QBoCUqMQAvD_BwE
I think it's selenium or something like that. I have never tried it, but I doubt it would make a big difference.
This advice is probably a bit more accurate:
https://batteryuniversity.com/learn/article/how_to_restore_and_prolong_lead_acid_batteries
I have had SLA batteries that got dried out and just needed some distilled water to perk up. Getting them open is generally difficult.
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