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Old 11-19-2020, 02:48 PM   #1
Mini-Skoolie
 
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Need battery help

Is there someone who can help me out with my lithium “smart” batteries. They are acting strangely. I am only getting power when I have them plugged into a 12 amp battery charger. Occasionally, when I fiddle with the connections, they will work for a minute or so then conk out. They are “smart batteries” with “advanced lifepo technology “. I believe that means they have some saftey features that shut them off if there is too much power, they drop too low or reverse polarity, among other things. I’d love any thoughts on how to reset them or perhaps I’m charging them wrong. Thanks.
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Old 11-19-2020, 04:03 PM   #2
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Quote:
Originally Posted by Whalby View Post
Is there someone who can help me out with my lithium “smart” batteries. They are acting strangely. I am only getting power when I have them plugged into a 12 amp battery charger. Occasionally, when I fiddle with the connections, they will work for a minute or so then conk out.
Have you verified the voltage with a multimeter or some other method (this would be a good first step if not). Measure right at the battery terminals with and without the charger connected.

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Originally Posted by Whalby View Post
They are “smart batteries” with “advanced lifepo technology “.
This is just a series of empty marketing words that isn't really saying anything useful. What is the brand or if you don't know that can you link to the product page.

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I believe that means they have some safety features that shut them off if there is too much power, they drop too low or reverse polarity, among other things.
Drop-in lithium batteries are different from their lead acid counterparts. They have the battery but they also have what is called the BMS (Battery Management System). Its job is to protect the cells from conditions that would harm them or be dangerous. Normally overvoltage, undervoltage, and often overcurrent, and high and low temperature. They also balance the cells but that is an aside.


Based on the fact that the battery seems to work when the charger is on (how do you know the battery works in this situation?) it seems possible that the BMS is detecting undervoltage and isolating the battery from loads.


Its hard to say with much certainty without knowing the voltage of the battery and the brand/model battery.
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Old 11-19-2020, 04:46 PM   #3
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Last week you were having problems probably due to possible overcharging, this week it seems you may be problems having with undercharging. And in both cases you aren't providing enough information to narrow down the problem.



I'm not sure if you ever followed any of the trouble shooting steps or guidance from your last post or got your problem sorted out.


It will be hard to get any useful help without providing basic technical details and context about the problem.


For starters:
1. A link to your battery
2. A link to your charger
3. Multimeter voltage reading at battery terminals with and without charger connected
4. Did you resolve your previous problem and if so what was the issue and what was the solution?
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Old 11-21-2020, 09:01 AM   #4
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or starters:
1. A link to your battery- this is one of the problems. The company that makes the batteries is out of business and I can’t find much information on them on line. The brand is “Smart Battery” and here is a link to the page Amazon has up for them SMART BATTERY 12V 100AH Lithium Ion Battery https://www.amazon.com/dp/B00I8UKIAG/ref=cm_sw_r_cp_api_i_cNcUFb3G32DSW?_encoding=UTF8& psc=1 it’s no longer a picture of the battery on there but the description is still there. You will see that it’s “currently unavailable “ and the reviews of the product are about what I have experienced.
2. A link to your charger- it’s no longer available but I’ll post a picture below
3. Multimeter voltage reading at battery terminals with and without charger connected- I don’t have a multimeter but my shunt says I have 100% charge and the voltage reading is usually around 13
4. Did you resolve your previous problem and if so what was the issue and what was the solution? I kind of fixed it. I was able to talk with someone at the company that bought “smart battery” and although they don’t make it any more he suggested that I unhook the negative terminal and shock the battery with the charger. When I did this, it would work for a while. Sometimes 12 hours sometimes 30 seconds. My biggest question is do I need to just scrap these batteries and buy something new or are these salvageable. They were 750 each and I can’t get any kind of refund so it would be nice to figure it out.
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Old 11-21-2020, 04:52 PM   #5
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Hmmm,
Not much to go off of, but my first instinct after looking at the amazon page you linked to is it has to do with the batteries.


They have 5 total reviews, 4 are 1 star and at least 1 alleges fraud, 1 alleges they have an F rating from the BBB, and 56 complains filed.


They provide no technical information about what they sell (including not even specifying whether the matter is Lifepo4 or some other type of lithium ion).


If your shunt accurately measures voltage, and 13v is the precise reading that is 3.25vpc which is far from 100% for lifepo4 (not sure about other lithium chemistries) but its also not near 0%, so its not immediately clear to me what your issue is.


Its really hard to say what is happening without and technical knowledge of the battery or the BMS


I think your best path forward (short of just replacing the batteries) is to try to isolate and narrow down the problem through testing, Try to rule out potential issues one by one. A proper multimeter will help in this process and is not too expensive.
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