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    Lossigy LiFePo 12V 200Ah battery test.

    Got a Lossigy LiFePo 12V 200Ah battery from Amazon recently. I've charged it to the manufacturer's recommended 14.6V and ran a capacity test. I used a DL24 smart load and ran a Constant Current test at 12A. With such a low load, I've got around 206 Ah. So far, everything looks good. I will...
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    Ammeters and diodes

    Substracting? What substracting? If you wish to use Demestres ammeters you can keep shunt connection as is but just put some addition al circuitry on low voltage part of it. Something based on Op-Amp or MCU to read voltage and rectify/convert it to be acceptable by ammeter head. You can even...
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    Ammeters and diodes

    I'd just use ammeter like this
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    Is 2P 1S panel setup possible? w/o causing issue?

    Actually maximum allowed amps depends on insulation temperature rating. For 12 AWG wire 20Amp limit is for 65C rated insulation. If you have a 90C rated wire insulation you can use 12AWG for up 30Amp About power...
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    Looks like you need not a BMS but just a battery equalizer. Something like this one -
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    Containing a battery pack meltdown.

    It's very hard to be killed by 120V AC if your skin is dry. I was many time zapped by 220V and couple times I was stupid enough to accidentally touch one 220V wire by one hand and another wire by another hand. Still alive :)
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    LiFePo batteries have much longer lifespan (3000-5000 charge/discharge cycles vs ~500), so it definitely has an economic sense.
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    Please help me learn why this happened so I don’t do it again!!

    Yes, if switch is fully open or fully close. But when you do switching - high voltage will cause an electric arch. Higher voltage - longer arc(in time and distance). An electric arch is generating high frequency RF emission and current pulsations. Inductors and capacitors inside of MPPT may...
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    Containing a battery pack meltdown.

    Exploded cell will leak enough electrolytes to make distilled water conductive.
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    Looks OK. In general a 100Ah LiFePo battery is a OK replacement for 200Ah deep-cycle lead-acid.
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    I just destroyed $500 worth of batteries by doing nothing.

    They are completely OK for this below 3Amp current.
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    Containing a battery pack meltdown.

    15Kwh will heat up and completely boil out around 21 liters of water.
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    WANTED! Internal resistance tester.

    It's not exactly true. You can use a YR1035 to test battery of any capacity. However it can measure internal resistance as low as 0.30--0.50 milliohms or higher. A high capacity cells may have a very low internal resistance, and it can be out of YR1035 range. Typical 100AHr LiFePo cell has...
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    Solar voltage lower when connect; theft or hidden conversion?

    Solar panel gives you maximum voltage at zero Amps and maximum current (Amps) at zero volts. In both cases you have a zero Watts. An MPPT charger is trying to squeeze maximum Watts by choosing the best Volts/Amps ratio.
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    Battery charger for lifepo batteries before series wiring.

    IF slow charging (8 Amp) is OK for you I can recommend an ISDT nano Q6 It support a lots of chemistries including LifePo4. But you need an external DC 16-30V power supply and couple of XT-60 female connectors to wire a power supply and battery...
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    Sizing a MPPT charge controller - upgrading from PWM

    So for both 2s2p and 2s3p you need a controller with at least 50V input voltage. For 2s3p you will have up to 30Amp. And controller should support 24 Volt batteries. There are lots of such controllers. For example:
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    Cheap charger

    Should be OK
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    Powering 12v modem from bluetti 12v 3amp port

    Looks like 5.5mmx2.1mm connector . But could be some other size.
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    Powering 12v modem from bluetti 12v 3amp port

    What exactly modem do you have?
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    VOLTS How to determine

    What is 1920 mvh? Do you mean 1920 KWh?
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    why is my bolt on fuse getting to warm

    Do you have a still washer between lug and battery? If so it could be a reason for heating. Non copper/aluminum washer should be placed only between lug and nut.
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    Pros / Cons of using a DC to DC CC/CV to charge a LiFePO4 from the alternator

    Yes PWM controllers have max input rate for voltage. They also have max amp rate they can provide for battery charging. So PWM controller like this one will limit your battery charging power consumption by...
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    New open source smart BMS

    Cool initiative! Are you going to share schematics of cell modules and control unit?
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    What to do with...

    Most like some MOSFETs are fried. But you need to have tools and knowledge to find a real reason. You can try to sell this board on eBay.
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    Testing Amp Hour ratings of a battery

    Actual lead acid (including AGM) battery capacity depends on discharging rates. Higher discharge Amps get lower capacity. Usually battery Ah rated for 20Hr discharge. Check your battery datasheet for exact numbers. And please note that your 36Ah rate is for full discharge, not for 50%.
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    Battery use and generators

    I'm using small gas generator similar to this one - as an emergency back up for my RV. It's cheap but quite useful. I'm also using it for tent camping.
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    Question on Wiring

    It's not a possibility. It's exactly how it works. Extra inverter dedicated for router is an overkill.
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    Question on Wiring

    Yes, all routers use 5V, 3.3V and 1.8V for electronic inside. Input in 10-14V range should be completely OK.
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    Series/parallel with AC

    There is no problem to connect AC consumer in series or in parallel. But connecting two or more AC sources is much more complex task.
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    Series/parallel with AC

    Yes and No. For AC you should consider phase shift between sources. Why are you asking?
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    power off

    Most mechanical switches (relay/contractor) are fast enough for in-home consumers. However control circuit is slow in many cases. It could be a long delay between actual power failure and contactor engagement.
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    Victron BMV-712 and SmartShunt update

    Beta release is better than Alpha. An Alpha releases usually are not available for public.
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    power off

    60Hz - > 16.6 ms period time. So 3-5ms switching time will not noticed by 99.99% of home equipment. But do not mix relay/contactor switching time with system transfer time (time between power failure and switching complete). Some system may be slow on power failure detection. Actually most of...
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    Got what?

    I'd split them and use 2 separate charge controllers for each group to get a better efficiency. If you have a space - definitely yes. You can set them to best angle/orientation. And will be much easy to maintain/clean them. Even a small amount of dust can reduce efficiency significantly...
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    Inverter without shore power/alternator/generator charging

    If invertor is not grounded GFCI will be useless. 500W/240V = 2.08 Amp I wouldn't be concerned to much about fire hazard.