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This is to follow up on a post I made last night regarding an evident 12v battery failure. I'm starting a new thread in a bid to make sure as many people as possible see it.
The advice I've received is to buy a new battery, not just get my old one tested and recharged.
Does it make sense to pick a Lithiium Iron battery? I'm pretty sure I saw somebody had done that on one of the YouTube videos I'd watched previously on 500e maintenance. I know they're a good bit more expensive than a standard battery. I'm willing to pay the extra money if a lithium battery would improve performance or decrease the likelihood of the battery going dead in the future.
Thanks in advance for any suggestions.
 

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2013 FIAT 500e
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Right, & after 2 years, get a little portable jumpstarter for peace of mind. Just make sure you keep it charged, as some lose charge every quarter-year or so.
 

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I'd suggest Antigravity if you're serious about a LI 12V car battery. They go into pros and cons on their webpage; particularly their Youtube video:

I looked at these resources prior to buying one. I took advantage of a July 4th 15% off promotion and free shipping; I go into these things in a different thread here. The timing was right and I needed a 12V battery and I didn't like how the OEM lead acid left me stranded. You're going to buy whatever you want to buy, hopefully that's the information you're looking for.
 

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2017 Fiat 500e (Billet Argento), 2015 VW Golf Sportwagen TSI 5MT (Tungsten Silver), 2002 Honda VFR
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For me, a regular lead acid H5 battery from wherever you find it for $100~ and a portable $50 lithium jumper is all you need. Not paying hundreds for a lithium that may or may not outlast the car lol.
 

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Right, & after 2 years, get a little portable jumpstarter for peace of mind. Just make sure you keep it charged, as some lose charge every quarter-year or so.
This is to follow up on a post I made last night regarding an evident 12v battery failure. I'm starting a new thread in a bid to make sure as many people as possible see it.
The advice I've received is to buy a new battery, not just get my old one tested and recharged.
Does it make sense to pick a Lithiium Iron battery? I'm pretty sure I saw somebody had done that on one of the YouTube videos I'd watched previously on 500e maintenance. I know they're a good bit more expensive than a standard battery. I'm willing to pay the extra money if a lithium battery would improve performance or decrease the likelihood of the battery going dead in the future.
Thanks in advance for any suggestions.
The 12v battery is used only to operate the lights and "wake up" the car's computer and system. It doesn't need any "cold cranking Amps". A jump-start booster costs about $50-$75 and fits nicely in the boot. I charged mine up to 100% and I go out and check it on the first of the month. So far, after 3 months, it's still 100%.
 

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2017 Fiat 500e (Billet Argento), 2015 VW Golf Sportwagen TSI 5MT (Tungsten Silver), 2002 Honda VFR
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Still wish there was a way to “wake or manually jump” the DC to DC converter so a jumper won’t even be needed as it will just pull current from the HV battery until you go get a 12v battery.
 

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Or if you could start it without a 12V, maybe don't even go get one! That would save even more weight than lithium, for less cost than a mototbike batt (as used by some owners).

This thread was started after a car with a DEAD 12V was able to activate its 12V electric powered door locks, whose 20A fuse indicates considerable power requirement. If the HV/DC-DC can be awakened for that, why not for starting?
 

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What I find ridiculous this hybrid car require an auxiliary battery at all as those don’t have starters they use the high-voltage motors to start the engine so I’m not even sure what the 12 V really is for aside from radio and interior stuff? I mean there isn’t a alternator on those cars either, everything can essentially run off the HV battery and the DC converter.
 

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What I find ridiculous this hybrid car require an auxiliary battery at all as those don’t have starters they use the high-voltage motors to start the engine so I’m not even sure what the 12 V really is for aside from radio and interior stuff? I mean there isn’t a alternator on those cars either, everything can essentially run off the HV battery and the DC converter.
The 12V battery serves two purposes. First is that it's the solution to the catch-22 of high voltage battery isolation. When the EV is off the HV battery needs to be isolated from the rest of the car. If HV battery power is used to drive the isolating contactors, then the battery wouldn't be isolated. So the 12V battery serves as the driver for the isolation system.

The second is simply the fact that most automobile electrical is 12V. Lights, radio, etc. It's easier to simply drop in a 12V battery to power that bus than to convert everything to something else.

ga2500ev
 

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The 12V battery serves two purposes. First is that it's the solution to the catch-22 of high voltage battery isolation. When the EV is off the HV battery needs to be isolated from the rest of the car. If HV battery power is used to drive the isolating contactors, then the battery wouldn't be isolated. So the 12V battery serves as the driver for the isolation system.

The second is simply the fact that most automobile electrical is 12V. Lights, radio, etc. It's easier to simply drop in a 12V battery to power that bus than to convert everything to something else.

ga2500ev
The thing is it already does though through the converter how else is the 12v even get charged.
 

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The thing is it already does though through the converter how else is the 12v even get charged.
The DC-DC converter is outside of the battery after the contactors. So the startup sequence is that the 12V battery engages the contactors, which connects the HV battery to the rest of the system including the converter, which then provides charging power to the 12V battery.

ga2500ev
 

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The easiest thing for the auto industry to use is a 12 volt system to power the contactors used for isolation. While a standard lead acid may be overkill for powering the contactors, it is the easiest battery type for them to incorporate. Production and distribution networks are well established as are recycling programs. Their behavior in a wide range of environments is understood etc.
 

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What I find ridiculous this hybrid car require an auxiliary battery at all as those don’t have starters they use the high-voltage motors to start the engine so I’m not even sure what the 12 V really is for aside from radio and interior stuff? I mean there isn’t a alternator on those cars either, everything can essentially run off the HV battery and the DC converter.
They did it that way because it was the quickest and cheapest way to bring the 500e to market. Outside of the electric drive, they are reusing the electrical system from the gas car. This is the practical reality of building a car.
 
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