john61ct said:
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 said:
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 said:
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 said:
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 said:
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 said:
No dice. Looks like it's 15s or ~$100 for the extra cells.
then dont. dont overstretch your budget if you dont need to.