LiFePo4 15s Charger?

Batteries, Chargers, and Battery Management Systems.
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flippy   100 MW

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Re: LiFePo4 15s Charger?

Post by flippy » May 14 2021 11:40am

999zip999 wrote:
May 14 2021 10:42am
Meanwells work great but won't turn off till you unplug it.
wich is not a problem and is actually a desired feature when the bms is balancing.

fun fact: virturally no charger turns their output off, just like a regular meanwell.
The bitterness of low quality remains long after the sweetness of low price is forgotten

999zip999   100 GW

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Re: LiFePo4 15s Charger?

Post by 999zip999 » May 14 2021 2:34pm

Fippy what my kingpan charger from Ping doesn't shut off ??? After full charge. I have three meanwells 24v set to 28v each for 84v and at end of charge the top and bottom meanwells green light turn off. I unplug everything and just plug in the 3 chargers again and all three green lights go back on
??? What's going on ? Meanwells are great you have to get the right one

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flippy   100 MW

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Re: LiFePo4 15s Charger?

Post by flippy » May 14 2021 2:48pm

no, your charger does not shut off.

the light on your ping cahrger only indicates that the current has dropped below the set level. thats all. it does not mean anything. think of it as a light on your dashboard of a car that turns red if you go above 10mph and back to green if you slow down.

you can change the setpoint where the led changes with a pot on the inside just like you can change the current and voltage with different pots. its just a cheap aliexpress charger, they all work the same and use the same chip. :wink:

only "real" chargers like the IMAX B6 and its clones. but those are actually programmable, they are not dumb and require skill to operate. not very useful for the averge consumer.

that your meanwells turn off is probably because you have not set them properly and they fault out. you need to set them EXACTLY at the same voltage in order for a series setup to work without faulting out. they are quite sensitive in their upper region and are quick to fault out and shut down. the ELG and HLG series are less prone to this behaviour. some series like the HRP wich are meant for medical devices are much more sensitive. i like the HLG and the HRP because they are nigh unbreakable.
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john61ct   100 GW

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Re: LiFePo4 15s Charger?

Post by john61ct » May 14 2021 7:40pm

There are many ways to balance that work within a proper charge regimen conducive to cell longevity.

If your BMS requires holding CV for more than a few minutes in order to "finish" balancing, then you're doing it wrong, either replace the BMS or stop using it for balancing.
flippy wrote: virturally no charger turns their output off, just like a regular meanwell.
Please don't over-generalise just because your personal experience is so limited

You are using the word "charger" wrong, that term is not valid for raw power supplies or DCDC converters. If it doesn't auto-terminate it is not a charger.

A generic term that covers all three is "charge source".

Satiator is a good example of a proper charger.

Any hobby style balancing charger as well.

Brusa, Elcon and DeltaQ are all proper chargers.

Some like Thunderstruck use an external controller.

A decent BMS can be used to control the charge source, but then you have no backup failsafe HVC for when the primary fails.


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Re: LiFePo4 15s Charger?

Post by john61ct » May 14 2021 7:45pm

Dropping to a lower Float voltage is termination of the charge cycle.

That is indeed what proper chargers do, some might do so prematurely if your goal is to truly get to Full.

Better ones let you adjust the (CV) Absorb Hold Time

Really all this focus on CV / Absorb cycle is a holdover from using lead chemistries,

for lithium banks better to just shut down completely, and just based on voltage (CC only) is just fine, no need in regular daily cycling to get to top cap utilization, harmful to longevity.

Skirmish   100 mW

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Re: LiFePo4 15s Charger?

Post by Skirmish » May 14 2021 10:46pm

999zip999 wrote:
May 13 2021 10:00am
Can't you buy a few more cells from battery hookup.
No dice. Looks like it's 15s or ~$100 for the extra cells.

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flippy   100 MW

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Re: LiFePo4 15s Charger?

Post by flippy » May 15 2021 3:51am

john61ct wrote:
May 14 2021 7:40pm
If your BMS requires holding CV for more than a few minutes in order to "finish" balancing, then you're doing it wrong, either replace the BMS or stop using it for balancing..
do you even understand how cheap bms actually balance? comments like this seem to indicate that you dont. if it takes longer then a few minutes it onyl means that your battery needs more time to balance. this indicates wear on the battery, not an indication of a shitty bms.
john61ct wrote:
May 14 2021 7:40pm
You are using the word "charger" wrong, that term is not valid for raw power supplies or DCDC converters. If it doesn't auto-terminate it is not a charger.

A generic term that covers all three is "charge source".
Satiator is a good example of a proper charger.
Any hobby style balancing charger as well.
Brusa, Elcon and DeltaQ are all proper chargers.
Some like Thunderstruck use an external controller.
yes, i know the difference, that is why i mentioned it specifically in my previous post. but sadly for most people there is no technical or physical difference between what is just a CC/CV supply with a fancy light or a "charger", in 99% of cases its the same thing. virturally nobody uses actual "chargers". not even your phone has it, its also just a dumb CC/CV setup.
charge termination is not a thing for lithium cells, its only a thing for cells where you actually CAN overcharge them with sustaining charge voltages like SLA and NIMH batteries for example. this does NOT apply to lithium.
for the sake of argument we can ignore people that use RC-style chargers.
john61ct wrote:
May 14 2021 7:40pm
A decent BMS can be used to control the charge source, but then you have no backup failsafe HVC for when the primary fails.
and that is where you go off the deep end and go into the area where its painfully obvious you actually dont understand the material enough. first off we can ALL agree that no factory fitted bms on ANY bike, battery or whatever is generally discussed on this forum has a "decent" bms. so even bringing up such a bms (wich you basically only find in cars) in a topic like this is simpy beyond theoretical in this forum and has no relevance here.
second: you suggest that a BMS will not HVC properly if a "charge source" goes bad is simply wrong and shows a clear misunderstanding of the process.
john61ct wrote:
May 14 2021 7:45pm
Dropping to a lower Float voltage is termination of the charge cycle.
That is indeed what proper chargers do, some might do so prematurely if your goal is to truly get to Full.
Better ones let you adjust the (CV) Absorb Hold Time
Really all this focus on CV / Absorb cycle is a holdover from using lead chemistries,
we are discussing lithium batteries, not SLA.
john61ct wrote:
May 14 2021 7:45pm
for lithium banks better to just shut down completely, and just based on voltage (CC only) is just fine, no need in regular daily cycling to get to top cap utilization, harmful to longevity.
just stop.

i have said this before to you and a few others: you seem to be in need of some charging basics. i dont mind educating you but first you need to stop giving advice about a subject you are not qualified to give. you are mixing different topics like SLA/NIMH charging cycles into lihtium charging. its either a mistake based on wrong assumptions or not understanding the material enough to see the difference. either way: you (and several others) are out of your depth and are giving flat out wrong comments and/or advice on this topic.
Skirmish wrote:
May 14 2021 10:46pm
No dice. Looks like it's 15s or ~$100 for the extra cells.
then dont. dont overstretch your budget if you dont need to.
The bitterness of low quality remains long after the sweetness of low price is forgotten

Skirmish   100 mW

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Re: LiFePo4 15s Charger?

Post by Skirmish » May 15 2021 4:49am

flippy wrote:
May 15 2021 3:51am
then dont. dont overstretch your budget if you dont need to.
Yeah, I can't think of any drawbacks of running 15s significant enough to warrant that cost. The motor & controller are happy at the voltage from 15s and it seems that the HLG-xxxh-54A works with 15s.

999zip999   100 GW

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Re: LiFePo4 15s Charger?

Post by 999zip999 » May 15 2021 9:57pm

Mine are 24v HRP series. Yeah I probably don't have them adjusted not exactly to the same level. That makes sense thank you.

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