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by john61ct
Jan 23 2019 8:31am
Forum: Battery Technology
Topic: LFP mobile House bank - xSyP serial vs parallel design thoughts
Replies: 39
Views: 2281

Re: LFP mobile House bank - xSyP serial vs parallel design thoughts

john61ct wrote:
Jan 20 2019 2:49pm
Please someone check my charge rate math?
bump?
by john61ct
Jan 23 2019 8:20am
Forum: Battery Technology
Topic: Charging with a coil (Adaptto)?
Replies: 14
Views: 1900

Re: Charging with a coil (Adaptto)?

Thanks, but this not a practical howto question.

I am specifically asking for any supporting evidence available for the hypothesis I quoted above.
by john61ct
Jan 22 2019 7:56pm
Forum: Battery Technology
Topic: Charging with a coil (Adaptto)?
Replies: 14
Views: 1900

Re: Charging with a coil (Adaptto)?

"Optimal" would be more complex than the single-step CC-CV profile the PSUs are capable of. The amount of current you can push into a battery without damaging it is related to its state of charge (SOC); large for low SOC and decreasing as SOC increases. For example, the Tesla supercharger...
by john61ct
Jan 21 2019 9:49pm
Forum: Battery Technology
Topic: Clarification on the 20% Rule
Replies: 14
Views: 888

Re: Clarification on the 20% Rule

**Storage** sitting at lower SoC is good for longevity. But regularly **cycling** to low SoC guarantees **much** shorter lifetimes. Every chemistry I've seen, just different sloped curves. Avg cycling DoD vs predicted cycles is a standard spec chart. Lab conditions, wildly optimistic compared to IRL...
by john61ct
Jan 21 2019 9:39pm
Forum: Battery Technology
Topic: Clarification on wiring a BMS?
Replies: 11
Views: 2903

Re: Clarification on wiring a BMS?

I would not use a combi inverter charger.

In an overvoltage I just want to stop the charger, continue to feed loads.

In undervoltage I want to cut loads off but allow charging.

So I guess that requires a non-common port BMS?
by john61ct
Jan 21 2019 1:09pm
Forum: Battery Technology
Topic: Clarification on wiring a BMS?
Replies: 11
Views: 2903

Re: Clarification on wiring a BMS?

I'm learning myself here. Am I to understand with a common port that the P- line in my setup should be connected to the positive bus bar, the negative bus bar, and the positive post of the battery? What does "P- line" mean? What is a "common port BMS"? > to differentiate between ...
by john61ct
Jan 21 2019 11:58am
Forum: Battery Technology
Topic: Queen Battery QB26800 6800mAh 20A - the big guy!
Replies: 31
Views: 5502

Re: Queen Battery QB26800 6800mAh 20A - the big guy!

Under "Li-ion" i mean 3.6/3.7/3.8/3.85V Lithium cells but sometimes people refer to 3.2/3.3V LiFePO4 as Li-ion too. Yes they are, it's just an umbrella term for dozens of different chemistries, each with often wildly varying characteristics and usage / care protocols. So if anyone knows w...
by john61ct
Jan 21 2019 11:53am
Forum: Battery Technology
Topic: Clarification on wiring a BMS?
Replies: 11
Views: 2903

Re: Clarification on wiring a BMS?

There is no detailed manual in English?

The US company that sold it doesn't offer support?
by john61ct
Jan 21 2019 11:05am
Forum: Battery Technology
Topic: Clarification on wiring a BMS?
Replies: 11
Views: 2903

Re: Clarification on wiring a BMS?

Have you got links to docs for that BMS? There is no need for pack current to flow **through** the BMS. Detecting volts & amps, then control through robust contactors (relays, solenoids). For such a small setup, thorough automated protection will likely cost more than the bare cells. Boat RV or ...
by john61ct
Jan 21 2019 11:01am
Forum: Battery Technology
Topic: Queen Battery QB26800 6800mAh 20A - the big guy!
Replies: 31
Views: 5502

Re: Queen Battery QB26800 6800mAh 20A - the big guy!

And I assume you're happy with that ZKETECH EBC-A20 ? do you know of as good but higher capacity? 20A is a long time to wait testing 180+Ah prismatics. So far looking at chargers with regenerative discharge like PowerLab and 4010-Duo. Needs to work with LFP and lead banks. If this is a derail, pleas...
by john61ct
Jan 21 2019 10:55am
Forum: Battery Technology
Topic: Queen Battery QB26800 6800mAh 20A - the big guy!
Replies: 31
Views: 5502

Re: Queen Battery QB26800 6800mAh 20A - the big guy!

Great technical review. Bulk sources?

And I guess in this space when people say "lithium ion" as if it is specific chemistry, one should just assume it's LCO / LiCoO2, Lithium cobalt oxide like most 18650?

Sorry I'm a noob wrt cylindricals, DIY battery assembly.
by john61ct
Jan 20 2019 4:23pm
Forum: Battery Technology
Topic: Charging amps through JST balance wires
Replies: 44
Views: 2313

Re: Charging amps through JST balance wires

I don't know what you mean by "old original", a what you call a new one ;) original, UN-A6, hard to find in bulk later came UN-A6 Plus UNA6PLUS+ UNA9 Plus 9S the later ones talk about a "balance current", so that means (to me) can't be an independent balancing charger anymore, b...
by john61ct
Jan 20 2019 3:15pm
Forum: Battery Technology
Topic: Charging amps through JST balance wires
Replies: 44
Views: 2313

Re: Charging amps through JST balance wires

The Q6+ will only do 300W if you supply it with 24Volts. I use them regularly on 19V from Laptop supplies but not at 300W. They are great little chargers by the way. Any recommendations for a 19v or more laptop charger that isnt too hugeand cheap? The power supply is 12v that was with my old balanc...
by john61ct
Jan 20 2019 3:08pm
Forum: Battery Technology
Topic: Charging amps through JST balance wires
Replies: 44
Views: 2313

Re: Charging amps through JST balance wires

NOTHING compared to something like a BC168 or UN-A6 (which i prefer more) What makes UN-A6 better? You just mean the old original? Does it pulse like the BC168, allowing 8A charging over the little (#22 ?) XH wires rated for only 3A? Both seem hard to find cheaply in bulk. Do the later UNA6 "p...
by john61ct
Jan 20 2019 2:49pm
Forum: Battery Technology
Topic: LFP mobile House bank - xSyP serial vs parallel design thoughts
Replies: 39
Views: 2281

Re: LFP mobile House bank - xSyP serial vs parallel design thoughts

Please someone check my charge rate math? Given a block of 6 cells, target V of 3.45Vpc and a fixed 6A current limit per cell-wire. BC168 charging each cell independently, same as whole-string-charging wired serially, 6A @ 20.4V --> 20.7W input per cell, 124W going into the block as a whole. While b...
by john61ct
Jan 17 2019 7:30pm
Forum: Battery Technology
Topic: Charging amps through JST balance wires
Replies: 44
Views: 2313

Re: Charging amps through JST balance wires

Not charging, way they do the balancing takes forever.
by john61ct
Jan 17 2019 7:06pm
Forum: Battery Technology
Topic: LFP mobile House bank - xSyP serial vs parallel design thoughts
Replies: 39
Views: 2281

Re: LFP mobile House bank - xSyP serial vs parallel design thoughts

Yes I guess technically won't get to "hold Absorb at 14.6V until amps taper to .005C" full without boosting the voltage a bit.

But then a low-amp boost converter's cheap.

That degree of Full only needs hitting a few times a week for longevity
by john61ct
Jan 17 2019 6:10pm
Forum: Battery Technology
Topic: Why does my 12v charger output 24v?
Replies: 4
Views: 392

Re: Why does my 12v charger output 24v?

I've heard of batteries you can readout the details of every charge / use cycle
by john61ct
Jan 17 2019 6:09pm
Forum: Battery Technology
Topic: Why does my 12v charger output 24v?
Replies: 4
Views: 392

Re: Why does my 12v charger output 24v?

many such devices use proprietary chips to ensure only the makers products are used
by john61ct
Jan 17 2019 7:51am
Forum: Battery Technology
Topic: LFP mobile House bank - xSyP serial vs parallel design thoughts
Replies: 39
Views: 2281

Re: LFP mobile House bank - xSyP serial vs parallel design thoughts

I really appreciate you guys sticking with me here, has been very helpful. > LFP will not self-balance, period. Except in Parallel, right? No, it will not self-balance at all. Self-balancing is a mechanism by which cells will alter their own voltage Aha. I apologize, I meant between cells, in the ab...
by john61ct
Jan 17 2019 7:32am
Forum: Battery Technology
Topic: LFP mobile House bank - xSyP serial vs parallel design thoughts
Replies: 39
Views: 2281

Re: LFP mobile House bank - xSyP serial vs parallel design thoughts

If you parallel all 16 cells and have a many-hundred amphour, 3.2 V cell, it will need to be charged up to 3.55 V in order to drive any balancing. Yes, again, this was just to clarify my understanding, not about balancing as such. And CALB 180s are a great example of what I will use for very big ba...
by john61ct
Jan 17 2019 6:57am
Forum: Battery Technology
Topic: Charging amps through JST balance wires
Replies: 44
Views: 2313

Re: Charging amps through JST balance wires

through the main power leads, just using the balance leads for balancing
by john61ct
Jan 16 2019 8:26pm
Forum: Battery Technology
Topic: Charging amps through JST balance wires
Replies: 44
Views: 2313

Re: Charging amps through JST balance wires

I don't see any indication it charges via the balance leads by design.

And I mean some replace the flimsy connectors on the BC168 in order to safely go above 4-5A.

And no I meant the BC168 is a pulsing type charge power output, which keeps those thin wires cooler.
by john61ct
Jan 16 2019 6:34pm
Forum: Battery Technology
Topic: Charging amps through JST balance wires
Replies: 44
Views: 2313

Re: Charging amps through JST balance wires

Is that charger designed to charge that way?

BC168 apparently goes to 8A, but it's pulsing, lots less heat buildup vs CC/CV.

Many users say 4-6A is OK but must vary by batt model?

others re-solder heavier wires too.
by john61ct
Jan 16 2019 6:29pm
Forum: Battery Technology
Topic: LFP mobile House bank - xSyP serial vs parallel design thoughts
Replies: 39
Views: 2281

Re: LFP mobile House bank - xSyP serial vs parallel design thoughts

So, even if a given use case requires 24 or even 48V for total bank voltage, I **really** want to keep to set standard 150Ah @12V pack modules. These may well each include their own pack-level protections - first alarms, then automated isolation - temperature, LVD/HVD, maybe high current rate alarm....