SLA batteries for moped

[PhoenixOSU]

I've seen a few different brands for SLA batteries in the 20ah ish range. I have room for 6 22ah batteries under the seat, and I'd like to use that space fully, I have found a few candidates and can't decide which is best.

universal
UB12220

Ritar
RT12220EV

Tempest
TD22-12

I have heard from some that universal is a bit flakey, and they are the cheapest. Ritar I can't even find a picture. I haven't heard a word about tempest. I know that B&B is supposed to be the the bees knees, but they are also expensive. Would a set of 6 20AH B&B beat out a set of 22AH Tempest cells?

I'm running at about 25A nominal, 88A peak.

Any info appreciated.

 

[scoot]

We live and breath on B&B SLAs for our high amp draw Goped electric scooters. Several have been tempted by, and attempted the Tempest batteries and found they have fallen very short of performance hopes.

Here is a recent post from another forum that may help, but be cautious and ensure that you know how long the batteries have been shelved in storage before buying. These particular batteries are about 50% of normal full retail price, but I have not looked at the other current offerings from PowerStream. Hope that helps a little. I see no other replies here.

http://www.gopednation.com/forum/showpost.php?p=3638230&postcount=40

 

[317537]

I use Ritar 12224ev series batts on my golden hub and controller. Ive tired a few different brands and they just get slaughtered either by the direct drive or regen or current draw. My guess is all three.

The new ritar batts im having a few problems balancing ATM because they are new and contain both AGM and gel. I find to undercharge them for a few weeks and build them up to full charge overtime. Once they arent fighting the charger they settle in really well.

I got well over 1000 cycles out of my last batch because I can do 3 trips a day on these batts.

The 12224 are better because I dont discharge the 24ah batts too low and they last longest.

View attachment ritar.jpg

These 24 ah batts are not as large as other batteries of the same ah rating but dont let that fool you they weigh in at 7kg 15lbs per battery and are full of lead.

If you want to fiddle with gel AGM for a little bit these are the way to go as they are truly designed for the application of ev technology. 3 of them @36v isnt so bad but 4 of them requires some effort on the designer to make sure the bike can handle the weight, mostly the stand./

 

[PhoenixOSU]

Weight isn't a frame, as I have a whole unused 200lb of carrying capacity on my frame, and my 6kw hub can drive this thing all day long. I noticed that the Tempest are more expensive and don't review well, and there is only one place to get them that I've seen. B&B is held up on high by just about everyone. I may look deeper into these two, the ritar and b&b, I do have a bit of a size limitation in that I'm trying to fit 6 cells into a modified chamber designed originally for 4 cells, I removed the under the seat bucket to make room for three more than were there before, and the single battery compartment is used for a charger on board now. I'm not so much concerned with AH rating at 1A, but at around 15A which is where I will be operating when moving at around 30mph. Not all cells tell you this information, but I have been able to get some curves for comparison and the B&B had the best bang for buck.

The Ritar looks nice, but when I look at them on google shopping I can't find these, I find some black looking thing that is much larger, more of a boxy shape then the rectangle of the ones i see in your pic and in the datasheet, where did you get them?

 

[317537]

Ive got my Ritars within a .04v balance now and improving each cycle. I had to discharge them right down with a 50w halogen to knock off some sulphate they must of accumulated during shipping. Its was taking to long to cycle them in. I discharged them down to 11.75 and recharged them straight off. I also included some zener shunt resistor balance strings between the terminals and i cant put them out of balance even if I tried. I am using three parrallel 12v 5 watt zeners, 2 rectifier diodes and single 2.2 ohm 1 watt resistor per string on a 3 amp charger.





The circuit begins to conduct voltage at around 13.6v and lightly clamps each battery till full charge. It wont fully clamp the battery so the charger will achieve full mode charge. My last SLA's I used only two zeners in parallel and three diodes with a 1 mohm resistor as it didnt need to take out as much current because the batteries were well cycled before I added the shunt strings and ive modded the charger to deal out more current since. I was hard hitting the shunt at 14.1v and totally out of float range.

The zener drops within the range of 12v and 12.6v and the diodes drop .7 each so it is very light during float and has little effect when the battery is at rest. The resistor has no problem adjusting to full charge mode.

It keeps the batteries well balanced in float mode and the pack is at full capacity by morning, and well charged in quick mode with my 3.1 amp charger.

 

[PhoenixOSU]

I plan to use a 10amp or 20amp charger for some faster charging times, I may need to recharge mid day as I now live on a hill.

Where did you buy them from, I can't find a source for them (atbatt claimed to have them, but when i called them they confessed that they don't).

 

[gogo]

Odyssey/Hawker batteries have a good reputation for motorcycle conversions.

 

[317537]

I plan to use a 10amp or 20amp charger for some faster charging times,

Dont charge anything SLA @ 22ah more than 2.5 amps you will not get much capacity and it will boil the acid off. You could food them but that will require you to top them up with water often at that current and this is where life gets more difficult with sealed batteries.

Divide your amp hours between 8.5 to 10. EG 22 ah batts 2.55/2.2 amp charger. Accuracy isnt that important as you will drain the batts to their death within a year more than likely.

The zeners balancer helps as it reduces current at the high end of the charge considerably. This allows you to use higher amp charger, faster charging when charger is set at higher amperage and get more capacity due to the current knee the zener balance introduces. Its a bit of a waist of energy but their are gains to be had due to better balancing and more capacity over the whole string.


Sure put 200lbs of batteries on your scooter but then you will have more energy to burn as a result of the added weight on your scooter. The motor probably can handle it though so 33ah batts may fit your needs. Still a 3.8 amp charger should be what your want and no higher than 4amps.

My ritars are rated at 6 amp charging max, well that may be fine, but its not what I call high capacity charging unless you really fork out for a good charger that monitors the internal resistance carefully and backs right off during absorbtion mode, still you are not going to gain much more speed in charging to a decent capacity using SLAs and an overated charger, because absortion mode is going to take up the bulk of the time on smaller batteries.

Edit:
For mid ride charging just plug your 2.5 amp charger in anyway as you will not gain much more capacity at 10amps bar destroying your battery. Possibly rig up another resistor over the current limiter and a switch to up it to 3 amps for a 22ah batt for fast charging for mid ride charging. But you do not need this when you charge at night.

 

[317537]

http://www.ritarpower.com/products.aspx?catid=19&pcatid=13

RT12240EV

12v
Capacity 24ah
7.2"L, X 3"W, 6.5"H,
Weight: 15.5lbs
Max discharge 240 amps. Been removed but I remember.
Max recharge 6amps.

RT12200EV
12v
Capacity 20ah
7.1"L, X 3"W, 6.5"H,
Weight 13.6 lbs
Max discharge 200 amps. I think.
Max recharge 6amps.


Did some conversions for you.

If you go Ritar. I picked mine up for $110 each AU at Solar Hart and they make good small system solar batteries too. SO you will probably get them for less in US if thats where youre at.

Dont get the RT series without the EV on them they do not perform as well in EV applications..

Ritar make chargers at various voltage too.
http://www.ritarpower.com/products.aspx?catid=41&pcatid=13

 

[PhoenixOSU]

200lb? Thats a bit crazy for batteries in a 2 wheel vehicle, makes balance hard from my experience. I'm just planning to use 6S1P 24A Ritar batteries at about $43 each. The downside is the 4-6 week lead time on the cells, which makes it almost worth it to get a B&B that is in stock and will ship sooner.

I am willing to spend a fair amount on a charger as long as it fits and doesn't die on me, so I can plug in wherever I'm at to a nearby outlet. 6amp 72V is a lot, but less than the $300 one I was looking at. Do you know of a good balancing charger? This would help considerably.

6amps to charger 24ah, that is at least 4 hours, probably ending up somewhere between 4-8 for a 100% charge, though I don't plan on draining them that far very often, part of my rationale for having 24ah batteries is that I can stay in the 0-50% D.O.D. range and they may last longer this way.

This charger it what I was looking at, 10A.
http://www.chargingchargers.com/quick-charge/ob72-10.html

Or if I want to balance them the way diy EV people do it sometimes, I could buy 6 of these
http://www.batteryspace.com/leadaci...floatingforworldwidewith6afuseulcelisted.aspx

The target is to have a midrange moped/motorcycle that can do the 3 miles to and from campus at least once per charge, I live on a hill for the first half mile of the trip its down hill then flat, speed 35mph tops, 6kw kelly hub motor and controller. I'd like to be able to make the trip to and back twice to a charge if needed.

 

[grindz145]

200lb? Thats a bit crazy for batteries in a 2 wheel vehicle

I think you can find a way to balance them, Honda found a way to balance my 700lb ST1300 just fine

 

[PhoenixOSU]

have you guys ever played with switching by way of a connector from series to parallel pack structure? I worked out a way of doing it safely with Anderson connectors such that when I plug the charger into the pack it puts the cells in parallel, and when I plug in the controller it puts them in series. My only big concern is in the parallel connection that balancing may cause some brief high currents, could these damage the cells?

 

[scoot]

I am not an expert on this topic, but I'll offer the following experiences. On our electric goped scooters, we use a 24v - 2s2p set up with SLAs. To achieve a quasi-balancing scheme, many of us install a "balance wire" between the two battery banks like so (it is the black wire running from both banks forward (right) to the yellow/purple connectors):



As long as the batteries are near the same state of charge (hence voltage), little or no current will pass in this wire when hooked up. However, if one of the main battery bank connectors comes loose during operation then high amounts of current will pass through this wire from one bank to the other and that is why a fuse and/or at least large gage wire on this wire is highly recommended. I am currently using a 5 amp fuse that is highly visible so I''ll know at a glance if something goes wrong.



The purpose for this "balance wire" is primarily to help give a "leg up" so to speak to the weakest cell in the system, thus keeping the overall system voltage up into the controller's operating range a little longer which helps extend range a little bit with older battery sets. Plus I believe it has somewhat of a balancing effect also when charging. The balance wire remains connected at all times. Hope that helps some.

BTW I am very curious how you went about your series /parallel connecting strategy with the anderson connectors. I have had a similar notions myself. could you explain and/or provide pics?

 

[PhoenixOSU]

yea, after looking at it, it would be best to use either a BMS type solution, or just some zener TVS clamps with current limiting resistors so the pack balances while charging, needs to be carefully calibrated though so that when all batteries are charged up it doesn't keep sucking current preventing the charger from going into float mode.

 

[317537]

Yes that looks cool, No need for regs on all the pbatts.

Ive found the 5 w zeners drop all vary and using two or even three in parrallel evens out to a nice average and they are more stable. I cant easily get TVS in any voltAge types here so 12v zeners are the closest I can do.

Do the diagonal thing when using parrallel batts and use the same wire lengths as short as possible.

View attachment sp.JPG

 

[PhoenixOSU]

4 to 6 week lead time on the ritar RT12220EV is a bit of a killer at 4-6 weeks unless you know of a better source, but its performance characteristics beat out the competition by far. The next two contenders are the EVP20-12 and the TH1295W. The TH1295W is $76, and the EVP20-12 is $56, compared to the RT12220EV at something like $40. The PSH-12180 is a good contender as well at $35, talk about cheep, and it has a strange discharge characteristic, seems to do better at higher currents compared to the others than at lower, and it doesn't have the nasty lead time or price of the other 3.

 

[317537]

Try maybe some lipos.

A pack of them could make you happy for a much longer. Take some weight out of that scooter and provide plenty of juice to get it off the starting line.

Search for some threads around about ES folk taking tool batts appart There are some interesting results.

https://endless-sphere.com/forums/viewtopic.php?p=197461#p197461

You could do 12X this deal and this would work as good as 6 SLA 20ah batts. Would cost you an extra approx $200 but probably last you 3X longer. I am seeing the value in lithium now, the price to performance is certainly worth a look these days.

 

[PhoenixOSU]

Really? At $58 each, for 20Ah at 74V thats $1160, SLAs are about $350 for something similar, though I haven't seen the capacity vs discharge rate curves for these either.

 

[PhoenixOSU]

On a similar note, the Ritar 22Ah battery lasts longer at high current than their 24Ah battery according to the data sheets on both. And they by far beat out the B&B, Power Sonic, Tempest, CSB, Universal etc in terms of bang for buck and outright performance. The 22Ah is only 6kg and the 24Ah is over 7kg. At 13amps (the approximated current draw from the batteries at 35mph using theoretical estimates and figures obtained from vehicle measurement) the 22Ah will last longer.

I read somewhere that when buying SLAs the only way to do it is to read many data sheets carefully and often price doesn't correspond to quality in the area that you need it in. at $40 each these SLAs are surprisingly good and a nice low cost alternative to LiFePO4 for those of us on a budget. I'm ordering 6 of the 22Ah cells.

 

[gogo]

I've kept Aerowhatt's solution in mind and your selection of batteries seem like they might be good candidates to parallel with a 20AH Ping.

Here's the Aerowhatt link:
Re: Mixing chemistries for most economic performance and range

I'll be interested in your experience with your battery choice.

 

[317537]

On a similar note, the Ritar 22Ah battery lasts longer at high current than their 24Ah battery according to the data sheets on both. And they by far beat out the B&B, Power Sonic, Tempest, CSB, Universal etc in terms of bang for buck and outright performance. The 22Ah is only 6kg and the 24Ah is over 7kg. At 13amps (the approximated current draw from the batteries at 35mph using theoretical estimates and figures obtained from vehicle measurement) the 22Ah will last longer.

I read somewhere that when buying SLAs the only way to do it is to read many data sheets carefully and often price doesn't correspond to quality in the area that you need it in. at $40 each these SLAs are surprisingly good and a nice low cost alternative to LiFePO4 for those of us on a budget. I'm ordering 6 of the 22Ah cells.

Can you give me a link to the datasheets please. On the site I get nothing.

 

[gwhy!]

Really? At $58 each, for 20Ah at 74V thats $1160, SLAs are about $350 for something similar, though I haven't seen the capacity vs discharge rate curves for these either.

that $58 is for 2 so its more like $580

 

[vanilla ice]

The C rate and cycle life of the extremely low end lipo is not as proven as the sla either.. We're not talking about the "cream of the low end" tunigy or the high end stuff here.

 

[317537]

Really? At $58 each, for 20Ah at 74V thats $1160, SLAs are about $350 for something similar, though I haven't seen the capacity vs discharge rate curves for these either.

that $58 is for 2 so its more like $580

I quoted $600 i put a guestimate delivery in there too and or price hike, close enough.

 

[vanilla ice]

Really? At $58 each, for 20Ah at 74V thats $1160

..more like $580

Or if you buy steveO's even less than 580!