New SLA battery problem Only 30 charges and lost most range

[Fusion80]

Bike info:
1000 watt rear drive direct drive.
48V 20AH battery pack SLA CHROME
Goes only about 5.3 miles before dieing


Hello everybody, I just recently bought 4 20 amp hour SLA CHROME batteries, About 2 months ago. I only recharge the bike every other day as I only use it every other day and I don't fully discharge it, I just use it for small errands around the town and then I recharge it right afterwards.

I inadvertently was running a battery with other batteries nearly discharged. I was using it for experiments and at the time was not experienced enough to understand that they all need to be balanced to be used them. After I realize what the problem was I charged up all the batteries individually with a 12V smart charger. Also connect them all together in parallel and let them sit overnight. I also tried discharging them with my power inverter at 130 watts until it beeps about 10v and shuts its self down and then recharge them.

The main problem is every time I go to charge up the batteries individually on my 12 volt smart charger, it says that it has 92% capacity of charge. And that can't be true because the bike dies out below 42 volts. I would expect that one of the batteries might have lower capacity of charge compare to the rest which is causing the whole pack to die prematurely. But they all seem to be level and have the same voltages.

My ebike says the battery's dead then quickly rise up to voltage showing nearly full charge around 52 volts or abit less.

What test should I do to try to find the problem battery unless they're all problem batteries they're just so new so hard to believe that there at the end of their life.

Thanks,

 

[bowlofsalad]

Hello everybody, I just recently bought 4 20 amp hour SLA CHROME batteries

Whyyyyyyyyyyyy

What test should I do to try to find the problem battery unless they're all problem batteries they're just so new so hard to believe that there at the end of their life.

Discharge test each individual cell to find their capacities, maybe you damaged one by over discharging from pack imbalance and it has horrible capacity through this. www.youtube.com/watch?v=wP0MhOcPmQY

The summary is you need http://www.amazon.com/gp/product/B001B6N2WK/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B001B6N2WK&linkCode=as2&tag=xbnijgbr-20&linkId=CCPNC6LVPCHLONCP http://www.amazon.com/gp/product/B00C1BZSYO/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B00C1BZSYO&linkCode=as2&tag=xbnijgbr-20&linkId=CYS3HW3FSYNOKD4U something like one of these, connect it to something like a power strip (I use anderson power pole connectors to do this) and then plug something like heatlamps or some old style light bulbs into the strip to reach the discharge rate that is similar to what you expect to achieve on average from your ebike. Observe the capacity and stop the test when satisfied. http://imgur.com/zH9IVQA

I don't know what sort of loss of capacity is lost through each cycle of an SLA, but the energy density, watt hours per quantity of weight, is really bad with SLA, it's just an awful chemistry to use for anything I can think of anymore.

https://bmsbattery.com/71-48v-li-ion

http://em3ev.com/store/index.php?route=product/category&path=35

I'd check out some packs from these places. The cost upfront probably seems like a lot, but this is how batteries, especially batteries worth getting, are. The number of cycles you can get from these types of packs can be pretty incredible. I recommend looking for packs that have something like ncr18650pf cells unless you have a really high draw setup going on.

Something you might grasp now, many people run packs with a 'bms', a battery monitoring system. This is a little device that specifically monitors voltage and prevents over charging and over discharging, and even balance cells. All chemical batteries that I know of are damaged to some degree from being over discharge or over charged, some situations are worse or more damaging than others, some chemistries aren't garbage after one over discharge or over charge, some chemistries might light on fire from abuse and so on. The BMS is a tool to help you protect your investment and beyond. The packs that I linked to, I think, all will include some version of a BMS. In my opinion, the minimum setup for a battery includes at least balance leads that connect to both the BMS and the pack so you can check pack balance one way or another with a multimeter. The most ideal setup is probably something like an adaptto that will verify BMS functionality and allow you to easily check pack balance. Some BMS include a display that shows you whats going on with the pack. I've used devices like the cellog 8s to check pack balance, but those things and devices similar all seem to be worthlessly inaccurate, at least the ones I've used, when comparing what I measure with even a really cheap multimeter.

 

[Ykick]

The worst thing you can do to SLA is to not fully charge it immediately after use and also use it partially discharged. Even if you’re unable to apply full power charge merely a trickle charge flowing back into SLA following discharge will greatly increase it’s service life.

Now you must dig deeper and figure out how to capacity test in order to determine the best course of action.

Honestly though, the best thing to do IMO would be to use a battery pack from our current century and not something from the previous century.

 

[wesnewell]

Yep, you've got to fully charge sla batteries immediately if not sooner after every use. Failure to do so will sulfate the plates and loose battery capacity. Left long enough in this condition and you'll find it very hard to impossible to recover that capacity. To try and recover what you've got now, you need to desulfate the batteries. If not too far gone you might recover most their original capacity. Some 12V battery chargers have a desulfate mode. It's sometimes called a recovery mode. I had about a 50% success rate in recovering batteries that were at close to 0V. If your batteries still take a standard charge, then you can probably recover all of them. But you need to do it asap. The longer you wait, the worse they get. Google desulfator

 

[dogman dan]

An electric vehicle needs a battery type with thicker lead plates than is typical for an emergency light or something. If you got them very cheap, they weren't the right kind. more lead = costs more.

If this is what you bought, https://www.chromebattery.com/12v-20ah-sealed-lead-acid-sla-battery-t6-connector.html

It says nothing about it being the type for an electric vehicle. But the price says they are shit. One with enough lead for an EV would cost about double that particular one.

Note in the specs, it says standby life, and only 12 pounds for a 20 ah. This battery is for an emergency light.

Also, they list the battery as 12v 20 ah, and 240 watts. These dorks don't even know the difference between a watt and a watt hour!!!

 

[dogman dan]

Here is a heavier battery, if you want to stick with lead.

http://www.electricscooterparts.com/scooterbatteries12v18ah.html

 

[999zip999]

Sorry Bro but this is the nature of lead. It's a learning curve to use lead with success.
Because of this lead can be Very costly for ebike use. Before buying a cheap ebay battery ask her what will work for your needs. Help is here before you buy.
Don't buy a Yugo.

 

[dogman dan]

Good lead can work ok. I talk to EBK customers that wonder if it's time... They bought the lead 2 years ago!

But pretty obvious, they didn't use it much, very short rides, and kept it charged all the time. Lead can be perfect, for riding a trike down to the pool at the clubhouse a mile and a half a way, 3 days a week in summer.

I tell people buy the lead if they won't ride farther than 3 miles there, and 3 miles back. Any more, I try to sell them the lifepo4.