{
"node": {
"id": "term:split-pack-charging",
"type": "Term",
"label": "Split-pack charging",
"properties": {
"id": "split-pack-charging",
"name": "Split-pack charging",
"aka": [
"bank charging",
"pack splitting",
"series–parallel switching"
],
"section": "topic-charging",
"definition": "Reconfiguring a pack with contactors so that its two halves charge in parallel at half the drive voltage. An 800 V vehicle such as the Tesla Cybertruck can then use 400 V fast chargers without a DC/DC booster; GM’s Hummer EV does the reverse, driving at 400 V and switching the halves into series to charge at 800 V.",
"related": [
"pack-voltage",
"contactor",
"dc-fast-charging",
"series-parallel",
"dc-dc-converter",
"hpc"
],
"url": "https://lemonergy.com/learn/glossary/split-pack-charging/",
"mentions": []
}
},
"edges": [
{
"id": "edge:6170",
"source": "term:split-pack-charging",
"target": "topic:topic-charging",
"type": "belongsTo",
"properties": {
"sourceFile": "terms.json"
}
},
{
"id": "edge:6171",
"source": "term:split-pack-charging",
"target": "term:pack-voltage",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:6172",
"source": "term:split-pack-charging",
"target": "term:contactor",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:6173",
"source": "term:split-pack-charging",
"target": "term:dc-fast-charging",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:6174",
"source": "term:split-pack-charging",
"target": "term:series-parallel",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:6175",
"source": "term:split-pack-charging",
"target": "term:dc-dc-converter",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:6176",
"source": "term:split-pack-charging",
"target": "term:hpc",
"type": "relatedTo",
"properties": {
"sourceFile": "terms.json",
"meaning": "Related context; not a causal claim"
}
},
{
"id": "edge:6177",
"source": "term:split-pack-charging",
"target": "visual:pack",
"type": "illustratedBy",
"properties": {
"sourceFile": "visual-pages.json"
}
}
],
"neighbors": [
{
"id": "topic:topic-charging",
"type": "Topic",
"label": "Charging and discharging",
"properties": {
"id": "topic-charging",
"name": "Charging and discharging",
"lede": "How current goes in and comes out, and the limits that stop it.",
"context": "Separate regulation from availability.",
"example": "The same CC–CV law can operate overnight or during a short depot stop.",
"lesson_url": "https://lemonergy.com/learn/fundamentals/capacity-and-c-rate/",
"lesson_label": "Open charging quantities"
}
},
{
"id": "term:pack-voltage",
"type": "Term",
"label": "Pack voltage",
"properties": {
"id": "pack-voltage",
"name": "Pack voltage",
"aka": [
"400 V system",
"800 V system"
],
"section": "topic-pack",
"definition": "The nominal voltage of the full series string, about 400 V in most electric cars and 800 V in newer ones. Doubling the voltage halves the current for the same power, so cables, connectors and losses shrink and charging can be faster.",
"unit": "V",
"related": [
"series-parallel",
"dc-fast-charging",
"high-voltage-interlock",
"insulation-resistance"
],
"url": "https://lemonergy.com/learn/glossary/pack-voltage/",
"mentions": [
"nominal-voltage",
"string"
]
}
},
{
"id": "term:contactor",
"type": "Term",
"label": "Contactor",
"properties": {
"id": "contactor",
"name": "Contactor",
"section": "topic-hvsafety",
"definition": "A heavy-duty electrically operated switch that connects the pack to the vehicle or inverter and opens it on fault or shutdown. Packs use at least two, one per pole, plus a pre-charge path to avoid welding them on the first connection.",
"related": [
"pre-charge",
"battery-disconnect-unit",
"pyrofuse",
"bms"
],
"url": "https://lemonergy.com/learn/glossary/contactor/",
"mentions": [
"inverter"
]
}
},
{
"id": "term:dc-fast-charging",
"type": "Term",
"label": "DC fast charging",
"properties": {
"id": "dc-fast-charging",
"name": "DC fast charging",
"abbr": "DCFC",
"aka": [
"rapid charging",
"HPC"
],
"section": "topic-infrastructure",
"definition": "Charging from a station that supplies DC straight to the pack, bypassing the car’s onboard charger, at 50 kW to over 350 kW. The BMS, not the charger, sets the current from moment to moment, which is why the charge curve tapers as the pack fills.",
"related": [
"fast-charging",
"onboard-charger",
"pack-voltage",
"preconditioning",
"charging-curve",
"evse"
],
"url": "https://lemonergy.com/learn/glossary/dc-fast-charging/",
"mentions": [
"charger",
"bms"
]
}
},
{
"id": "term:series-parallel",
"type": "Term",
"label": "Series and parallel connection",
"properties": {
"id": "series-parallel",
"name": "Series and parallel connection",
"aka": [
"xSyP"
],
"section": "topic-pack",
"definition": "Cells in series add their voltages; cells in parallel add their capacities and share current. A pack is described as, for example, 96s4p: 96 groups in series, each of 4 cells in parallel. Series strings need balancing; parallel groups self-balance through their shared terminals.",
"formula": "V = n_s·V_cell, Q = n_p·Q_cell",
"related": [
"module",
"cell-balancing",
"pack-voltage",
"volt",
"fuse"
],
"lesson": "fundamentals/battery-basics/#cell-module-pack",
"example": {
"title": "Assemble an ideal 4s2p pack",
"text": "Eight identical 3.6 V, 5 Ah cells arranged as four series groups with two cells in parallel give 14.4 V nominal, 10 Ah and 144 Wh. Interconnect losses, cell variation and usable voltage limits are additional constraints."
},
"url": "https://lemonergy.com/learn/glossary/series-parallel/",
"mentions": []
}
},
{
"id": "term:dc-dc-converter",
"type": "Term",
"label": "DC/DC converter",
"properties": {
"id": "dc-dc-converter",
"name": "DC/DC converter",
"section": "topic-pack",
"definition": "The power electronics that step the high-voltage pack down to 12 V or 48 V for the auxiliary systems, replacing the alternator of a combustion car. Boost converters also appear between an 800 V pack and a 400 V charger.",
"related": [
"auxiliary-battery",
"inverter",
"pack-voltage"
],
"url": "https://lemonergy.com/learn/glossary/dc-dc-converter/",
"mentions": [
"charger"
]
}
},
{
"id": "term:hpc",
"type": "Term",
"label": "High-power charging",
"properties": {
"id": "hpc",
"name": "High-power charging",
"abbr": "HPC",
"aka": [
"ultra-fast charging",
"ultra-rapid charging"
],
"section": "topic-infrastructure",
"definition": "DC charging at 150 kW and above, up to about 400 kW for cars, usually at 800–1000 V so the current stays within what cable and connector can carry. Liquid-cooled cables make the currents of 500 A and more practical.",
"related": [
"dc-fast-charging",
"xfc",
"pack-voltage",
"charging-curve",
"mcs"
],
"url": "https://lemonergy.com/learn/glossary/hpc/",
"mentions": []
}
},
{
"id": "visual:pack",
"type": "Visual",
"label": "Series voltage and parallel capacity",
"properties": {
"title": "Series voltage and parallel capacity",
"summary": "Count series and parallel connections separately.",
"readout": "4S2P: 8 cells, 14.8 V, 10 Ah, 148 Wh.",
"formula": "V_pack = Ns V_cell; Q_pack = Np Q_cell",
"note": "Identical 3.7 V, 5 Ah cells; ideal equal current sharing and no losses.",
"software": {
"status": "reference",
"label": "Reference concept",
"body": "Ideal pack ratings use V_pack = Ns V_cell and Q_pack = Np Q_cell. The core energy helper can multiply these ratings. Imbalance and current sharing require additional models.",
"href": "../fundamentals/capacity-and-c-rate/"
},
"html": "Voltage along one series string