Help me choose a battery
#21
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Its very unlikely that you would actually be able to charge the battery at 17A. I dont think you'll ever make a high enough voltage differential to pump that much juice in unless the battery was already dangerously low.
If anyone wants to DIY a ballistic battery just buy a set of standard size A123 LiPOFE4 cells from ebay or aliexpress and put it together. I pulled mine apart after some of the cells went **** up and they wouldnt honor the warranty. I ended up scraping it because apparently when my cells went **** up the balance wires all melted and when I popped the top off there was shorting and fire and I promptly whipped it out of the garage into the snow. Lol.
If anyone wants to DIY a ballistic battery just buy a set of standard size A123 LiPOFE4 cells from ebay or aliexpress and put it together. I pulled mine apart after some of the cells went **** up and they wouldnt honor the warranty. I ended up scraping it because apparently when my cells went **** up the balance wires all melted and when I popped the top off there was shorting and fire and I promptly whipped it out of the garage into the snow. Lol.
I knew that Ballistic used the A123 cells, but doing a DIY job with the same level of packaging would be difficult, for me at least.
What size is the wires coming off of that cell you linked? Using a SB style connector with this battery would be a really clean install, and easy to remove every once in a while for balance charging.
#22
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Sounds like alot of fun! Did you use their balance charger occasionally to make sure the cells were balanced?
I knew that Ballistic used the A123 cells, but doing a DIY job with the same level of packaging would be difficult, for me at least.
What size is the wires coming off of that cell you linked? Using a SB style connector with this battery would be a really clean install, and easy to remove every once in a while for balance charging.
I knew that Ballistic used the A123 cells, but doing a DIY job with the same level of packaging would be difficult, for me at least.
What size is the wires coming off of that cell you linked? Using a SB style connector with this battery would be a really clean install, and easy to remove every once in a while for balance charging.
The size wires coming off the is either 6 or 8ga. I forget. The 5.5mm bullet connectors work really well and it wasnt hard to solder some 4ga wire onto the car side bullets.
#24
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Mine is yet to be relocated. And has only started my personal car twice so far. But we've put a few in other street driven cars locally now. Including the aforementioned civic daily driver who left his headlights on. Passenger footwell would be my choice with a second set of high amp terminals like an anderson connector right near it in case you needed to jump to switch to a different battery in an emergency.
#29
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
LOL. It is a pretty skinny wire after all. I am being speculative on weight, but if I recall, I was thinking I would save ounces in relocating the wire.
I planned to leave the battery in the back and relocate the wire to the driver compartment thus removing just a few feet of wire.
I planned to leave the battery in the back and relocate the wire to the driver compartment thus removing just a few feet of wire.
#32
Moderator
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/moderator.png)
iTrader: (12)
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,884
Total Cats: 3,075
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
$41
15lbs
230CCA
Super Start Lawn & Garden U1RH - Lawn & Garden Battery | O'Reilly Auto Parts
For comparison, the standard Miata battery, which is already quite small, is
$105
25lbs
320CCA
15lbs
230CCA
Super Start Lawn & Garden U1RH - Lawn & Garden Battery | O'Reilly Auto Parts
For comparison, the standard Miata battery, which is already quite small, is
$105
25lbs
320CCA
#33
Elite Member
Thread Starter
iTrader: (5)
Join Date: Oct 2007
Location: Canton, Ga
Posts: 2,156
Total Cats: 66
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I'm leaning on the EXT20 now, since I can't get the Yuasa cheap without paying $13 shipping.. at that point I may as well get the legit one for $100. I have no need for anything drawing dark power so I'm going with a cutoff switch as well. Since my head has been in the machine shop for nearly a month and I havent gotten an ETA or even an estimate I haven't thought about it much lately. I'll just buy when I get the head back.
I'm staying away from flooded cell batteries to that leaves out the good, uber cheap lawnmower batteries. No leaking on my rust free chassis.
I'm staying away from flooded cell batteries to that leaves out the good, uber cheap lawnmower batteries. No leaking on my rust free chassis.
#34
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
The Deka's are good AGM's. They're basically generic branded Braille. Anything cheaper will be a lead-acid and/or not worth your time.
Most motorcycle batteries don't have the CCA needed for a car engine plus all the additional loads versus almost none on a bike, save a Gold Wing et al.
If you wanted to go into LiFePO4 territory, you're going to spend more coin. Shorai's LFX36 is a great battery that I used in my Lotus with excellent success, $265 via Amazon Prime. I also just rebuilt my Chimera [4S2P] with Headway 38120HP cells plus top-down balancers and it was around $200, not including that I already had the CF case, cell holders and copper bus bars.
The difference between lead-acid/AGM and LiFePO4 is if you don't drive the car everyday. Storage battery tenders need to be different, as a lead-acid tender will smoke a LiFePO4 in short order.
Most motorcycle batteries don't have the CCA needed for a car engine plus all the additional loads versus almost none on a bike, save a Gold Wing et al.
If you wanted to go into LiFePO4 territory, you're going to spend more coin. Shorai's LFX36 is a great battery that I used in my Lotus with excellent success, $265 via Amazon Prime. I also just rebuilt my Chimera [4S2P] with Headway 38120HP cells plus top-down balancers and it was around $200, not including that I already had the CF case, cell holders and copper bus bars.
The difference between lead-acid/AGM and LiFePO4 is if you don't drive the car everyday. Storage battery tenders need to be different, as a lead-acid tender will smoke a LiFePO4 in short order.
#36
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Amazon.com: Battery Tender BTL24A360C Lithium Iron Phosphate Battery: Automotive
Voltage: 12V
Cold Cranking Amps: 360
Case Dimensions: 6.49” (165mm) length x 3.38” (86mm) width x 5.11” (130mm) height
Operating Temp: 0 - 140°(F)
Weight: 2.6 lbs
Voltage: 12V
Cold Cranking Amps: 360
Case Dimensions: 6.49” (165mm) length x 3.38” (86mm) width x 5.11” (130mm) height
Operating Temp: 0 - 140°(F)
Weight: 2.6 lbs
The price is excellent though, so it has that going for it. The equivalent [actually pretty much identical in terms of cells] Ballistic Evo2 12-cell is much more expensive.
#37
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
7.5Ah isnt all that small. Especially for a miata. If your alternator crapped out you should still be able to drive ~20 minutes with the headlights off.
If you want to DIY your own version of that battery the cells cost ~$7.75 a piece if you buy them with tabs already spot welded on so that you can make the battery pack with solder.
If you want to DIY your own version of that battery the cells cost ~$7.75 a piece if you buy them with tabs already spot welded on so that you can make the battery pack with solder.
#38
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Nope, prismatic cells. I'll try and find my source again.
Edit: found this Amazon Q&A, but somewhere I saw a forum thread where someone dismantled one.
Edit: found this Amazon Q&A, but somewhere I saw a forum thread where someone dismantled one.
#39
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
That is most likely a 4S3P of A123 26650's, given the rated amperage of 360A [120A x3]. 1.9 lbs would be the 12 cells, the case and terminals the balance. 7.5Ah is pretty small, your alternator had better be in top shape and your electrical loads minimal.
The price is excellent though, so it has that going for it. The equivalent [actually pretty much identical in terms of cells] Ballistic Evo2 12-cell is much more expensive.
The price is excellent though, so it has that going for it. The equivalent [actually pretty much identical in terms of cells] Ballistic Evo2 12-cell is much more expensive.
Maybe headlights and turn signals somewhere down the line.