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Acumulator li ion 18650 pentru ups


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Am un ups unda sinusoidala pura. Aș putea pune o baterie din acumulatori 18650? Toate specificațiile arata numai baterii pb și gel. Vreau să folosesc ups pentru o pompă de recirculare la un termosemineu. Pompă grunfost cu trei trepte de 150, 200 și 250w.

 

 

 

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Problema e în principal la încărcarea acumulatorilor. Circuitul de încărcare al UPS-ului e calculat să încarce acumulatori Pb. Ca să încarce acumulatori Li-Ion, circuitul respectiv trebuie reconstruit ca să nu cauzeze incendiu prin supraîncărcare, sau să activeze supapele de suprapresiune ale elemenților și să le întrerupă continuitatea ireversibil.Alt aspect ține de diferența dintre tensiunile minime de lucru între tipurile constructive (Pb versus Li-Ion), respectiv pragul la care UPS-ul își încetează funcționarea ca invertor din cauza scăderii tensiunii acumulatorilor la o valoare minim acceptată. Iar modificările astea pot fi uneori destul de complicat de realizat, necesitând chiar resoftarea controllerului în unele cazuri.Și nu ai marjă de eroare, fiind vorba de siguranță. Poți da foc casei cu un aparat care nu utilizează corect acumulatorii Li-Ion, cunoscuți pentru periculozitatea lor.

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Eu am facut la vreo 5-6 ups-uri bacnuri de acumulatori li-ion dar am folosit bms bune si am facut intotdeauna un acumulator mai mare ( chiar si de 3 ori) decat avea ups-ul 

De asemenea imperecherea si testarea celulelor 18650 trebuie sa fie temeinica

Nu recomand celule recuperate din baterii de laptop, nu se merita.

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Lithium Iron Phosphate: LiFePO4 cathode, graphite anode
Short form: LFP or Li-phosphate Since 1996
Voltages    3.20, 3.30V nominal; typical operating range 2.5–3.65V/cell
Specific energy (capacity)    90–120Wh/kg
Charge (C-rate)    1C typical, charges to 3.65V; 3h charge time typical
Discharge (C-rate)    1C, 25C on some cells; 40A pulse (2s); 2.50V cut-off (lower that 2V causes damage)
Cycle life    2000 and higher (related to depth of discharge, temperature)
Thermal runaway    270°C (518°F) Very safe battery even if fully charged
Cost    ~$580 per kWh[1]
Applications    Portable and stationary needing high load currents and endurance
Comments
2019 Update:    Very flat voltage discharge curve but low capacity. One of safest Li-ions.
Used for special markets. Elevated self-discharge.
Used primarily for energy storage, moderate growth.

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Dar pe net fiecare descrie dupa pregatire si experienta:

CITAT NET:    

HOW TO CHARGE LIFEPO4 BATTERIES WITH A LEAD-ACID CHARGER

Most lead-acid battery chargers can be used with LiFePO4 batteries as long as they are within the appropriate voltage guidelines. AGM and Gel algorithms typically fall within the LiFePO4 voltage requirements. The voltage for flooded battery charging algorithms is often higher than LiFePO4 charging requirements, which will result in the BMS disconnecting. If this happens, it is generally good practice to replace your charger for one with a LiFePO4 charge profile. Since the BMS protects the battery, using lead-acid chargers will typically not damage the battery.

Note that if the BMS disconnects due to low voltage, a lead-acid battery charger may not be able to reconnect the BMS, even if the charger has the acceptable charging parameters to charge LiFePO4. This is because when the BMS disconnects, the lithium battery will not have a voltage as it will read 0V on a voltmeter, while lead-acid chargers require the battery to read out a voltage to start charging. If the battery is reading 0V, the lead-acid battery charger will not be able to understand that a battery is connected and that it should start charging. This is also true for some low-quality lithium chargers. It is always recommended that you invest in a high-quality LiFePO4 charger to ensure high performance and longevity. 

Edited by dumitrumy
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Am o baterie de mașina care ține aproximativ 2 ore. Aș vrea să fac un 3s li ion pe care să-l incarc separat, nu de la ups, și să-l conectez numai atunci când bateria de mașina este terminată și curentul nu a revenit. De la 12,6v până la 10,3v mai merge ceva pompa de recirculare. Repet: îl încarc separat. Se poate?

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Se poate, dar se poate un 4s LFP cu BMS compatibil cu UPS, exista pana la 200AH, sau nivelul urmator sistem fotovoltaic hibrid tot cu acumulatori LFP, de anul asta disponibil si sodiu ion, functioneaza si pe frig.

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