DIY 12v lithium battery for Prius - step by step with pictures

Discussion in 'Gen 3 Prius Accessories and Modifications' started by jacktheripper, Nov 29, 2020.

  1. VEZzie

    VEZzie Junior Member

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    Haha yeah. Probably because after some people removed their backseats, etc.. they are adding heavier things (bedframe blocks, fridge, inverter, etc) :D

    Anyway.. I think for hybrids, aside from the obvious weight-factor; battery chemistry, capacity & age really matters for mpg.
    In my experience, if the battery is too old, the ICE engine will keep running, trying to charge the 12V battery back to an acceptable level. But unfortunately it will never happen due to sulfation, so the ICE pretty much runs all the time.

    This mod gives the Prius a completely different type of battery, which has better discharge rate & usable capacity. For people who like to add another backup aux with isolator/combiner relay/FET, Lithium will definitely give more satisfactory results than AGM.
     
  2. kenoarto

    kenoarto Senior Member

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    How much do all the parts cost?
    Posted via the PriusChat mobile app.
     
  3. ASRDogman

    ASRDogman Senior Member

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    It's not vented, so it gets hot.
    He could use a fan from an old computer case, or processor fan and attach a tube and
    route it out through the fender, it would help to cool the battery.
    And 24 volts would certainly give enough power to all accessories! :)

    It's a nice little project for used cells. I do hate to waste stuff like that.
    How much did that welder cost? It's a nifty tool!
     
  4. sam spade 2

    sam spade 2 Senior Member

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    There are a LOT of assumptions in that post.
    You don't know the quality of the replacement cells so the "longevity" is unknown. You also don't know if the charging system will charge them properly or not. Given that a good AGM often can last from 5 to 7 years, the longevity might be much less.
    And how are you measuring "performance" ?
    And how much better is "far" better ??

    It is an interesting experiment.......but the outcome is "far" from a given.
     
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  5. sam spade 2

    sam spade 2 Senior Member

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    So, how about you explain the "point" in simple to understand terms.
    And stop throwing around inflammatory insults.
     
  6. PriusPilotSurfer

    PriusPilotSurfer New Member

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    Some of the replies are so critical they are funny. Forum discussion life at it's best and the same on every forum near and far. Come on everyone. Jack here is not selling these batteries or is his information DIY have any monetary compensation. He is sharing a DIY and that is all this is. Is the weight a huge factor? Probably not. This discussion has good points and points where it just seems people are bored and want to stir the pot. I'm not building a 10 second 1/4 Mile Prius Hybrid here. I found Jack's DIY informative and useful. Many of us are tech nerds and we like to be hands on and DIY. 'Inflammatory insults?' LOL 'Senior Member' above please lighten up. No one is insulting anyone. You don't like the DIY, don't read it. You want to buy an AGM, go for it. You want to add more cream to your coffee, by all means! Glass half full, vs half empty. I do appreciate reading the info a few have posted with discharge information and graphs. These forums are a great place with a ton of information. I appreciate Jack and his contribution here.
     
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  7. AzusaPrius

    AzusaPrius Senior Member

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    Hey sam, relax you should be used to remarks like this on this forum since a lot of people you chat with on here do the same.

    Think of replies like a mirror, if you reflect something then you will get that reflection back.

    Hopefully this clears up any confusion you may have now and in the near future.

    In the meantime if you do not have any input that is of any value then keep your two cents.



    Posted via the PriusChat mobile app.
     
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  8. Prodigyplace

    Prodigyplace 2025 Camry XLE FWD

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    Just use the ignore button on Sam. It makes the forum much more pleasant.
     
  9. TMR-JWAP

    TMR-JWAP Senior Member

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    There is so much irony in these posts I'm about to die from laughing...…..
     
  10. vvillovv

    vvillovv Senior Member

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    I was thinking lithium when I check the price of 12 volt battery replacement as opposed to aluminium lead or iron. Than I saw lithane and forgot about it.
     
  11. fotomoto

    fotomoto Senior Member

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    No affiliation but I'm thinking of going this route as it seems to hold up to mountain biking use:
    VRUZEND battery kit V2.1 – VRUZEND DIY Battery Kit
     
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  12. vvillovv

    vvillovv Senior Member

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    I have a few of the smaller versions of
    ryobi-18v-9ah.png
    thinking plug and play - when the tools break and leave me with some empty sockets to play with

    I also like these 2170's
    MilwaukeeRed18v-12ah-2170-2.jpg

    though the supercharger is almost as much as the pack. And if you want the 2170's instead of the older 18650's you have to get the specific part numbers, cause the M18Fuel names don't tell you which is which.

    remembering the ole design basic - break before make - although it means something different electrically than how it sounds to the common listener.
     
    #32 vvillovv, Nov 30, 2020
    Last edited: Nov 30, 2020
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  13. Grit

    Grit Senior Member

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    I’m just waiting for someone to post about the general rule about charging lifepo4 batteries under 32F long term wise.
     
  14. TMR-JWAP

    TMR-JWAP Senior Member

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    So let's crawl in the rabbit hole. The individual batteries are $4 each. Each one is 3.2 volts and rated at 6000mah. 4 connected in series would get you 12.8 volts and 6ah capacity with an 18 amp max. An oem battery is 45ah and 325 CCA. So to get an equivalent mah battery, you would need 7.5 of the 4S assemblies. Lets just go with 7, where capacity will be 42ah, just slightly less than OEM and a 126 amp max. That puts you at 28 batteries...$112 dollars. Throw in $11 for the control board shown in the thread. Throw in 5? bucks for an ammo box and now we're at $128. How many people actually have the equipment, materials or ability to assemble this with any amount of real reliability? Very few. So throw in some $$ for those supplies. Now throw in some $$ to cover the screwups, because the majority of people can't even torque a nut, much less do a quality solder/spot weld job). And wiring? LOL at that. But just for the hel* of it, let's assume it's assembled perfectly, exactly per this thread. Now look at the finished battery shown in the thread and installed in the car. Compare it to how cleanly the AGM battery installs. Now think about how comfortable you would be with your wife driving the car, or your 17 year old daughter driving the car.

    The question becomes, at what point is it just easier and 1000x more reliable in most instances (99%?) to just buy a good AGM that's designed for the job?

    If you just want a project to do, then fine. Have fun, experiment away. I've done plenty of weird projects just for fun and hobby. If you're doing it to save money or weight? You're pissing into the wind. The majority of people better make sure they have AAA on standby.

    NAPA has their top end AGM Prius battery for $195. They currently have a special going on where it's 20% off (all items) if you buy a $5 NAPA tool bag and three of anything in the store. Not three of the same thing, but just three items. Maybe oil, filter and a battery? That puts the battery at ~$155 and it has a 75 month warranty (18 month free replacement and remainder prorated). Good deals are out there, they have to be found.

    https://www.napaonline.com/en/p/NBP9851P

    If you really want to go crazy to save a few bucks, and don't care about AGM or venting...all you need to do is switch to Camry battery connectors and use this....

    https://www.lowes.com/pd/Deka-12-Volt-600-Amp-Farm-Equipment-Battery/50183729?cm_mmc=shp-_-c-_-prd-_-sol-_-google-_-pla-_-146-_-sosopemaintenance/accessories-_-50183729-_-0&placeholder=null&gclid=EAIaIQobChMIvry86uar7QIVDYeGCh0eeABWEAQYBSABEgIEP_D_BwE&gclsrc=aw.ds
     
    #34 TMR-JWAP, Nov 30, 2020
    Last edited: Nov 30, 2020
  15. AzusaPrius

    AzusaPrius Senior Member

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    As the title says DIY so this is not a sales pitch but an idea.

    Some people must have been shot down in life a lot a lot and think its is fun to shoot others down to feel better for some reason.

    A shame really

    Posted via the PriusChat mobile app.
     
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  16. Prodigyplace

    Prodigyplace 2025 Camry XLE FWD

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    But it is not economically helpful and is therefore off-topic for this area of the forum. It belongs in FHOP.
     
  17. vvillovv

    vvillovv Senior Member

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    Another great contribution to the DIY members here at PC by @jacktheripper
    Along with many thanks for the DrPrius app that has some nice features that work in the Prime as well and is "FREE" if you have a decent ELM327 to access the sensors in the prius.
    disclaimer: DrPrius testing features require an tiny fee to access.

    Cheers Jack and heres to your 12 volt install lasting as long or longer than your Lithium Replacement Packs for Gen2 and Gen3 prius have already in your prii with your location and driving techniques.
     
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  18. vvillovv

    vvillovv Senior Member

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    @fotomoto That kit is a nice alt to solder or weld. I've seen that kit build in my pack learning journeys and I think it's a great idea.
    I've also been following this dudes channel when it shows up while I'm searching stuff. He goes pretty deep and this is a new one for me too, so I thought I'd share with those who liked this thread.

    as well as others that might be interested.

    Here's another pack build that shows a nickel fuse plate similar to the kind of fuse plate Tesla uses now. I've only seen the newer Tesla fuse plate design once in a video and I can't find any jpgs of the newer design anywhere. Plenty of the old plate with a wire fuse. Anyways this is a much thinner plate designed for the 24 volt pack build.
    https://youtu.be/np3EGmik1aU?t=355

    For those interested in the plug and play DIY idea mentioned a few posts up, here are some links
    for move info.

    All the reviews I've seen both at buy sites and in youtubes are off the charts for both the 2170 cell pack and the one key tools built to take advantage of them.

    As I mentioned above if one wants the battery packs with the 2170 cells, the part numbers on the millwaukee listed somewhere on their site are needed to make sure the correct pack is the one chosen when buying, for those who can afford them.

    Super Charger I believe it charges only the 2170 packs 4x faster, please don't quote me on that though.
    M18™ & M12™ Battery Super Charger | Milwaukee Tool

    And the RedLithium HO packs and super charger page
    https://www.milwaukeetool.com/Products/Batteries-and-Chargers/M18-Batteries-and-Chargers/48-11-1812
    There are smaller Ah packs than the 12Ah pack shown in the link, that include the 2170 cells

    All the reviews I've seen, both at buy sites and mechanics that use them in youtubes are off the charts. For both the 2170 cell packs and the one key tools built to use them.
     
    #38 vvillovv, Dec 3, 2020
    Last edited: Dec 3, 2020
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  19. Mendel Leisk

    Mendel Leisk Witness Leader

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    Geesh, up here they want $451 CDN ($338 USD). :(

    IMG_4080.jpg
     
    #39 Mendel Leisk, Dec 3, 2020
    Last edited: Dec 3, 2020
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  20. jacktheripper

    jacktheripper Senior Member

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    That's the reason I built this pack when my friend called me up for help, nobody can justify the $200+ for a tiny Prius 12v AGM battery :mad:
    and since I already have the LiFePO4 cells in my garage, I literally only spent $2.99 on the ammo box and couple of hours of my time.
    PS: all my Prius have been running 12V Lithium for years.