A better SLA?

[Zippedy]

From my viewpoint, those K2 batts look like throwing money at a problem, rather than a solution.

But if they work for you, with <half the weight and a long life, that's great.

 

[circuitsmith]

I spotted circuitsmith's BMS thread a few days ago, but being a lipo virgin, I can't quite get my head around it.

For instance, with a 7S3P setup, how do you balance the 21 cells? Are there 6 sockets under the board for the 6 Turnigy balance plugs?

Yes, there are 6 sockets for the balance plugs.

I'm interested in selling the system, after some more field testing.

 

[999zip999]

Zippedy what is your budget ?

 

[Out-Spokin']

Interesting . . . . Apollo Energy Systems, Inc. (AES), Lead Foam Cobalt Batteries. Interesting, but still wetcells - designed to compete with Lithium.

http://youtu.be/r95OI0rD7Dk or
http://www.youtube.com/watch?v=r95OI0rD7Dk

 

[etriker]

From my viewpoint, those K2 batts look like throwing money at a problem, rather than a solution.

But if they work for you, with <half the weight and a long life, that's great.

Currie uses those for their li ion upgrade. It is cheaper to do it yourself and replace the batteries.

 

[lbz5mc12]

I don't suppose you'd be interested in getting 25 mph out of the 24V motor? Here's what you do:
1. Buy a 36V currie 5 pin scooter controller.
2. Buy a 36V 5 pin currie throttle.
3. Buy 3 sla batteries for 36V.
4. Ditch the original controller and throttle or put them in a box; probably better to put them in a box.
5. Buy a 36V sla charger.
6. If you can figure out how, you can use the existing battery cases to hold the batteries and wire them in series or you just put the batteries in a bag and strap them down to the rack. I'm not sure if your bike has the rmb batteries mounted to the rack or if they're frame mounted. We need a picture of your bike. Is this bike with a side mounted motor or a hub motor?
7. You can also buy a 16 tooth single speed left side southpaw freewheel on amazon which will put you at or over the 30 mph speed.

I've done this with my ezip skyline and there are pictures of it floating around on ES somewhere. If anyone actually happens to find said pictures you'll notice the hub motor(s). Just disregard the hub motor(s) because I've gone back to the original motor. Since those pictures were posted, I've also upgraded to a single pack of lithium. I still have the 15A sla pack but it's currently mounted on my roommate's bike which I've also recently upgraded to 36V. ?He has the currie kit on his bike. Also you may be interested in desulfators. I've got the 36V powerpulse model hooked up to the sla pack and it's been used well beyond it's 250 charge cycles.

 

[Zippedy]

Well, after a bit of further reading around, especially on ES, I've come up with a possibly workable, cheapo lipo 10ah setup for my 24v 300w bike...

...all be it, slightly overvolted to around 32v.
I might already have the 16 tooth conversion.

When plugged into the bike, the balance lead to the balance board would have a cell log 8.
Another cheap turnigy 8s alarm across the battery leads.

Although the charger and cell log 8 would be looking at pairs of cells, I hope I would be able to spot weak pairs.

I have shown power leads coming from the opposite ends of the packs from the balance leads for clarity (!).

Total around $175 shipped to UK (most from UK warehouse).

Almost plug and go.

Any obvious mods I should make to this scheme, before I go to the checkout?

 

[jonescg]

Can you see the multiple short circuits across the paralleled packs?

You will need to put connectors on all of the series connections, so you can disconnect the 4s packs before balance charging. Otherwise you will have sparkles

Edit - OK I see this is charging at 12 V. Nevermind. You will still need to disconnect your series connections before charging though.

Edit 2- It will still short circuit when you plug into the adapter board because you have the two packs in series.

 

[Zippedy]

I have put a little blob where there is a connection and a little bridge/bump to show where there is not.

The top two packs are parallel with each other and = 4s2p
The bottom two packs are in parallel with each other and = 4s2p
The top two are in series with the bottom two, so together = 8s

The top and bottom wires that loop back to the charger output (or the motor, when in use) carry 8s voltage - about 32v.

The 8s balance connector from the charger (or to the cell log, when in use) carries same voltage

The 4s connectors from the board each carry 4s and give 4s to each of the parallelled packs via the parallel balance cables.

I thought that that adapter board was specifically designed to allow 2 4s packs to be charged in series.

The adapter board should neither know, nor care, that the 4s packs are effectively 4s2p packs.

 

[Zippedy]

This (I hope) is another (simpler) way of looking at my plan:

Any drawbacks?

 

[jonescg]

OK, I thought the adapter board was charging the 4s packs in parallel. If they are literally 2 lots of 4s split directly from the 8s plug, then it will work as drawn.

 

[miro13car]

there is not better brand for Lead Acid battery than B&B brand.
I own Merida ebike originally lead, I planned to convert to lithium but B&B refuses to quit still is going strong after 3 summers.
Merida pedal-first motor is rated 200W only, it never runs for longer than 4-8 minutes at the time with assist kicking in.

 

[999zip999]

So a sla is better at shorter demands on the throttle and when up to speed to you help withpeddle assit to help keep speed and not keep at full thottle as keeping it pegged ?

 

[Kent]

While I am not a big fan of lead and agree with what has already been said about it, I came across this tidbit about lead that ZEV Electric Motorcycles is currently using. I don't know who makes it or where it can be sourced:

Compared to the ZEV4100 with the advanced Lithium batteries:

• The Lead is less expensive.
• Acceleration is slightly slower due both to the battery characteristics and the fact that the LA bike weighs approximately 145 kg / 319 lbs, which is approximately 24 kg / 53 lbs more than the lithium battery bike.
• Battery life is approximately 1/3rd as long as that of the lithium batteries. Expect about a 3.5 year life. However, they cost approximately only 1/3rd as much as the lithium batteries.
• Lead battery systems do not require battery management systems like the lithium battery. So that means a lot less parts to go wrong over time. This also means that the 4100 can be upgraded to a 5000 in the future with just a controller, one battery, and a new charger.

The Silicate lead battery used by ZEV are a completely different battery than the old lead sulfuric acid battery.
• They have only about 10% of the internal resistance of the old sulfuric acid battery. This allows these batteries to be charged in ½ the time of normal lead acid battery. • The discharge ability is much better allowing rapid vehicle acceleration with up to 4.5 times the ability to discharge without damage. • There is little or no temperature increases during charging or discharging. • The battery is far less sensitive to temperature being able to work normally at -50 C. • The battery has no memory. • The electrolyte is the ultimate green battery fluid as it can be used as a fertilizer. • The shelf life is in excess of 12 months without losing charge. So an unused vehicle does not run itself down. • The battery are non explosive. • The battery can be recharged at high currents of .8 to 1 C. • High discharge rates are not a problem given the low internal resistance. • There is not acid mist produced by charging. • The battery can be fully deep charged through over 500 cycles • The energy storage to weight ratio is about 24% better than lead acid.

http://www.environmentfriendlystore.com/shop/moped_motorcycle_scooters_29_ctg.htm

 

[ian.mich]

just get bulk charged parallel balance lipo and skip all the crap

 

[Chalo]

just get bulk charged parallel balance lipo and skip all the crap

Best max out your homeowner's insurance while you're at it.

This isn't exactly a vast community here on this forum, but we still have relatively frequent reports of lithium polymer battery fires. I don't like those odds at all.

 

[999zip999]

I agree they are hobby batteries. I always balance charge my A123's. You will have to be the total bms yourself ?

 

[ian.mich]

I agree they are hobby batteries. I always balance charge my A123's. You will have to be the total bms yourself ?

just pull <4C, discharge to 3.5/cell, balance every 10 cycles.

 

[999zip999]

What is the sicth does father want to help he's son or has his son taken the bait. Who's idea is it or who takes care of the dog and dog shit and all that so to speak ? This matter's !!! Plus or munus $$$ They havn't even rode it yet.

 

[Zippedy]

While I am not a big fan of lead and agree with what has already been said about it, I came across this tidbit about lead that ZEV Electric Motorcycles is currently using. I don't know who makes it or where it can be sourced:

Compared to the ZEV4100 with the advanced Lithium batteries:

Yada
Yada
The Silicate lead battery used by ZEV are a completely different battery than the old lead sulfuric acid battery.
• They have only about 10% of the internal resistance of the old sulfuric acid battery.
Yada
Yada

http://www.environmentfriendlystore.com/shop/moped_motorcycle_scooters_29_ctg.htm

Erm, I think that The Silicate lead battery they are referring to is a simple marketing hype for good ol' VRLA (SLA)batts.
Normal VRLA (SLA) batts apparently have silica dust in the gel electrolyte. But they are still lead/acid batteries.

The environmentfrienlystore is doing the old Baffle 'em with BS trick. There's no BS like green BS.

 

[LockH]

[BUMP] ... I see Carbon-Foam is still in the running...

http://azimuthsolar.ca/product-category/batteries/carbonfoambatteries/

3900 Cycles at 50% DOD; 1150 Cycles at 80% DOD

Best in Price
The long lifespan of the Firefly Oasis batteries mean every dollar stretches for the most cost-effective energy storage available. These batteries can live up 3-4 times longer than regular VRLA batteries for the same price and require no maintenance. With a rating of 90-95% efficiency and an unlimited depth of discharge, the Firefly Oasis ensures users get the most out of their purchases.

The Firefly Oasis batteries are best in their class for Kilowatt-Hour capacity, and because of the 100% DOD of the 12V G31, this powerful battery can compete with batteries twice its size with an average 50% DOD. This Firefly Oasis grants the lowest cost of ownership for every Kilowatt-Hour in your portable power systems.

The Firefly Oasis batteries also have considerably shorter charging times than competing AGM batteries, able to drop the charging time down by 30%. Fast charging allows these batteries to get the most out of solar charging in unpredictable weather.

 

[Toorbough ULL-Zeveigh]

just get bulk charged parallel balance lipo and skip all the crap

Best max out your homeowner's insurance while you're at it.

This isn't exactly a vast community here on this forum, but we still have relatively frequent reports of lithium polymer battery fires. I don't like those odds at all.

thatz y hees such a gooroo.

SLA ALL THE WAY!

 

[LockH]

Funny Guy... Read the fine print? "most cost-effective energy storage"

Energy STORAGE. There's a certain WEIGHT penalty to use for transportation? :wink: Their "lightest" 12V batt still weighs 74 lbs. each.

 

[Chalo]

Firefly Oasis batteries were originally marketed as something for commercial OTR truckers to run their creature comforts with when they're not hooked up to shore power. That's a less demanding application than EVs.