Anyone Replaced The Starter Battery with a Lithium ? The good and Bad ?

borabora said:

It's not a good idea.
- Your starter can draw 700+ amps which your battery may or may not be able to supply short-term but even if it can it may not be happy to do so frequently.
- A depleted LIFEPO4 battery can easily draw 2x its capacity in amps from the alternator (assuming you jump started the van). Your alternator cannot supply the current and voltage can drop into the havoc range. More likely, you can't jump start the van because of the huge load the empty battery represents.
- The battery's BMS can disconnect the battery for various safety reasons. When that happens your alternator will self-destruct.
There may be other reasons but you get the picture...

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Thank you for you the reply. Let me start with I agree the safe bet is the leave the starter battery as is and add this as second lithium battery for pack with 12 volts 560 amps. So your issues/questions in order:

1. The spec on a single lithium battery is 200 amps (250 surge) with a 280 amps total capacity, do you know what a lead acid battery maximum is ( So the starter load is 700 amps (surge) ?700 amp @ 12 volts = 8400 watts. Wow. is that a normal start or extreme ? Does anyone have a graph of the amps surge on start ? at what temperature was the test done ?

Basically,my understanding is a lithium ion battery will exceed performance of lead acid on all normal metrics (energy density, amps, etc.) What exactly is occurring the a lead acid battery exceeds lithium in the same space? I am curious that lead acid can outperform in this case.

2. The battery BMS will cut a 250 amps surge. I have a 2012 with a 220 amp alternator. The internal resistance is lower but alternator cable will limit I am guessing 100 amps based on research in this forum but this is the main question. Will a depleted lithium battery overwhelm an alternator ? A counter is comments I have seen regarding ambulances that abuse the alternator with overload and its rock solid. I have 1000 watts of solar on roof so anticipate the need for hard alternator usage only when I abuse (use) the AC. I see intermittent high demand, but when I what it I want all I can get in amps. So the racing questions is Where does it break down ? or where do I leave the track ? smile.

3. I agree with the concerns on the alternator, hence all my questions. So when does it break (graph ?) or do we never test the limit ? Hey, I am old shit disturber who is asking where the limit is before I jump. Thanks for all the help.

Best
tom

Thank you for you the reply. Let me start with I agree the safe bet is the leave the starter battery as is and add this as second lithium battery for pack with 12 volts 560 amps. So your issues/questions in order:1. The spec on a single lithium battery is 200 amps (250 surge) with a 280 amps total capacity, do you know what a lead acid battery maximum is ( So the starter load is 700 amps (surge) ?700 amp @ 12 volts = 8400 watts. Wow. is that a normal start or extreme ? Does anyone have a graph of the amps surge on start ? at what temperature was the test done ?Basically,my understanding is a lithium ion battery will exceed performance of lead acid on all normal metrics (energy density, amps, etc.) What exactly is occurring the a lead acid battery exceeds lithium in the same space? I am curious that lead acid can outperform in this case.2. The battery BMS will cut a 250 amps surge. I have a 2012 with a 220 amp alternator. The internal resistance is lower but alternator cable will limit I am guessing 100 amps based on research in this forum but this is the main question. Will a depleted lithium battery overwhelm an alternator ? A counter is comments I have seen regarding ambulances that abuse the alternator with overload and its rock solid. I have 1000 watts of solar on roof so anticipate the need for hard alternator usage only when I abuse (use) the AC. I see intermittent high demand, but when I what it I want all I can get in amps. So the racing questions is Where does it break down ? or where do I leave the track ? smile.3. I agree with the concerns on the alternator, hence all my questions. So when does it break (graph ?) or do we never test the limit ? Hey, I am old shit disturber who is asking where the limit is before I jump. Thanks for all the help.Besttom