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electrical:12v:self-jumpstarting [2024/03/20 19:40] frater_secessus [jump packs] |
electrical:12v:self-jumpstarting [2024/03/22 08:19] (current) frater_secessus [Self-jumpstarting] |
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Self-jumpstarting means jumpstarting one's own vehicle without the use of another vehicle. | Self-jumpstarting means jumpstarting one's own vehicle without the use of another vehicle. | ||
- | Note: regardless of specific method used, it will be gentlest on the system to **combine the batteries and wait a few minutes for the starter battery to come up** instead of immediately attempting to start. This will minimize the amount of current flowing from house bank to vehicle chassis. This may be especially important with Li chemistries that have BMS protections. | + | Note: regardless of specific method used, it will be gentlest on the system to **combine the batteries and wait a few minutes for the starter battery to come up** instead of immediately attempting to start. This will minimize((or eliminate, if the connection is broken prior to starting)) |
===== jumping from the house bank ===== | ===== jumping from the house bank ===== | ||
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+ | ===== waking lithium batteries ===== | ||
+ | Lithium banks can go dormant at low voltages in order to protect themselves: | ||
+ | - the BMS turns off the DISCHARGE channel to keep cell voltage from going any lower | ||
+ | - so the battery internally has ~11.0v or whatever but does not pass that voltage to the terminals on the outside of the battery case | ||
+ | - which means smart chargers don't see battery voltage | ||
+ | - and think there' | ||
+ | What we need is a //dumb// voltage source to get the party restarted. | ||
+ | * Rigs with IGN-triggered relays can briefly turn the key to ACC then back off.((don' | ||
+ | * Rigs with voltage-sensing relays will have to actually start the engine or press a manual override switch to activate the VSR and wake the lithium bank. | ||
+ | * Rigs with diode- or FET-based isolators would start the engine to spin the alternator and get power flowing through the isolator to the sleeping lithium | ||
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+ | ===== jump packs ===== | ||
+ | [[https:// | ||
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+ | ' | ||