FYI FORD MustangSteve's Ford Mustang Forum / Installing a smaller lithium battery with 24” radiator upgrade.

**Posted by RTM** 6/30/2024 4:36 PM

When I installed the 24” radiator in my 66 I was going to install the battery in the trunk. I did not offset the radiator when I did this mod because of the plan to move the battery to the trunk. Now I decided to mount is battery in the stock location. I’m going with a lithium battery that has 920CCA and is L6.5xW5xH6.8. I modified the battery tray to fit this size but still need to make support braces for it.

**Posted by Alan** 6/30/2024 4:55 PM

Top notch

**Posted by Rudi** 6/30/2024 5:01 PM

I really like the idea of the smaller sized batteries Ike the Odyssey.
Considering that lithium batteries in power tools need dedicated chargers I wonder how they survive with auto alternators?

**Posted by 6sally6** 6/30/2024 5:10 PM

Ain't you sump'in !!
Nice mod....
6sal6

**Posted by Nos681** 6/30/2024 7:02 PM

What system do you plan to use to charge the lithium battery?

What is suggested charge voltage for this battery?

Rudi brings up a valid concern about charging.

**Posted by Rufus68** 6/30/2024 7:38 PM

I would have bought the battery before doing all that work; however, I'm sure your mock up matches what they say. I just hope they really told the accurate numbers.

**Posted by Rufus68** 6/30/2024 7:45 PM

I was just doing some reading. And assuming that you are planning to get a LiFePO4 battery with a good built in BMS, it should charge fine from the car alternator. The built in BMS will take care of the battery. More reading would be necessary to confirm all of this. Definitely only choose a LiFePO4 battery though since these do not catch fire.

**Posted by RTM** 7/01/2024 3:26 AM

Well I can’t afford to buy the battery yet and money is going to keep me from getting this thing ready by the end of August when our son comes home. I did add a 1/4” per side for added insurance. If not I have another battery try I can cut up and do it again. lol

I had read something about charging but failed to ask the company about that. The only thing I asked is what their smallest car battery was. This is what they suggested. I’ll reach out to them today and ask.

https://antigravitybatteries.com/products/starter-batteries/restart-oem/atx30-hd/

My biggest thought was this is a simple approach to mounting it in the trunk. The lithium battery is not cheap but I’m sure buying everything I need to mount the battery in the trunk isn’t going to be far off. Let alone the time I’ll save keeping it up front. If you want to get picky there’s a weight savings going to the lithium battery up front versus going in the trunk.

**Posted by Nos681** 7/01/2024 4:53 AM

WOW are you S~ing me?
Smart battery or not.
It must be the latest craze down south with the heat.😜

Take a look at JEG’s and Summit to see small batteries that are available.
There are small AGM batteries that may fit your needs.
Some are lightweight and about 1/3 the cost.

JEG’s has Braille batteries for an example:

Last edited by Nos681 (7/01/2024 5:08 AM)

**Posted by TKOPerformance** 7/01/2024 5:07 AM

The lithium batteries work well in power tools. I had a bunch of Milwaukee stuff that all runs lithium. They can overheat though.

Personally I would run an AGM. I've had great results using them in my Diesel truck, which loves to kill batteries.

Lead acid just don't seem to last anymore. I think its overuse of recycled lead, and with all the restrictions on lead now I don't see it getting any better.

**Posted by RTM** 7/01/2024 5:44 AM

That’s why I like posting here. Great information and help here.

**Posted by RTM** 7/01/2024 12:51 PM

Rufus68 wrote:
I was just doing some reading. And assuming that you are planning to get a LiFePO4 battery with a good built in BMS, it should charge fine from the car alternator. The built in BMS will take care of the battery. More reading would be necessary to confirm all of this. Definitely only choose a LiFePO4 battery though since these do not catch fire.

The battery I link to states it has all of the features you mentioned a lithium battery should have.

It appears the battery listed with Jegs is not a lithium battery and does not need the same requirements? This battery also has less CCA, not that the difference should matter. The lithium battery claims twice plus in longevity.

My alternator is a one wire unit from CVF. They sell a kit to wire the alt up. I found this same kit on Amazon for $30 less than what CVF has it listed for.

**Posted by Bolted to Floor** 7/02/2024 11:35 AM

That's a pricey battery.

I got a lot of wire through Wire Barn back in 2016-2018 time frame. They were good to deal with. Buying 50 foot 2/0 SGT battery cable or welding cable would cost about half the price of the battery. Add in your time and the needed connectors and you could call it a wash.

The SGT cable is rated for 176 F. I was surprised their welding cable was rated for 221 F.

Always look for the temperature rating of the insulation no matter where you buy any cable... even for a battery under the hood. It might be big cable, but a low temp insulation rating will reduce the amount of cranking amps making it to the battery.
Edit
Looked at the car... memory is not what it used to be!! Battery calbe is SGX rated up to 257 F and meets SAE J1127, Ford MIL-56A, and Chrysler MS-3450 specfications.

Last edited by Bolted to Floor (7/09/2024 6:09 PM)

**Posted by RTM** 7/02/2024 12:14 PM

Bolted to Floor wrote:
That's a pricey battery.

I got a lot of wire through Wire Barn back in 2016-2018 time frame. They were good to deal with. Buying 50 foot 2/0 SGT battery cable or welding cable would cost about half the price of the battery. Add in your time and the needed connectors and you could call it a wash.

The SGT cable is rated for 176 F. I was surprised their welding cable was rated for 221 F.

Always look for the temperature rating of the insulation no matter where you buy any cable... even for a battery under the hood. It might be big cable, but a low temp insulation rating will reduce the amount of cranking amps making it to the battery.

I did not know that about wire. That’s good information to know.

**Posted by RTM** 7/04/2024 7:52 AM

Battery tray looks like a factory tray now.

**Posted by HudginJ3** 7/04/2024 7:56 PM

I put a certified Earth X battery in the Cub. For such a tiny and light battery it works really good. Sins the engine faster too. A friend also put one in his plane. There is no reason to not put one in a car given the price of a new automobile battery. They last about twice longer too.

**Posted by Rufus68** 7/05/2024 4:40 AM

RTM wrote:
Well I can’t afford to buy the battery yet and money is going to keep me from getting this thing ready by the end of August when our son comes home. I did add a 1/4” per side for added insurance. If not I have another battery try I can cut up and do it again. lol

I had read something about charging but failed to ask the company about that. The only thing I asked is what their smallest car battery was. This is what they suggested. I’ll reach out to them today and ask.

https://antigravitybatteries.com/products/starter-batteries/restart-oem/atx30-hd/

My biggest thought was this is a simple approach to mounting it in the trunk. The lithium battery is not cheap but I’m sure buying everything I need to mount the battery in the trunk isn’t going to be far off. Let alone the time I’ll save keeping it up front. If you want to get picky there’s a weight savings going to the lithium battery up front versus going in the trunk.

The battery you linked is Lithium Ion. That chemistry burns incredibly hot. Add LiFePO4 or Lithium Iron Phosphate to your search for a battery.

**Posted by RTM** 7/05/2024 4:56 AM

Hudginj3 the battery life is something I was thinking about but have done any comparisons yet. I know here in SWFL I get about 2-3 years out of a new battery that’s from Autozone. I can’t recall what brand we put in my son’s truck but it’s outlasted any other battery I e ever bought. I think we got it from O-Riley’s.

Rufus68 it looks like I have more to learn about battery’s. If heat from the battery I link is an issue then why are others using them?

**Posted by TKOPerformance** 7/05/2024 5:59 AM

This is the situation I was in with my Diesel. The factory batteries lasted 2 years. When they started to fail I talked to the best Ford Diesel tech in the area and he said they were going bad. I said the truck is only 2 years old. He said, yep, that's about how long they last. I bought a set of Interstate Megatrons. Lasted 5 years. Replaced them with another set when they went. Lasted 5 years. The third set lasted 2 years, I got them partially covered under warranty. The replacements lasted a year, and they tried to avoid covering them (only wanted to replace one). Replacements went about a year, warranty coverage was far worse than it had used to be (indicating they knew premature failure was an issue). At that point I'd had enough and researched other options. Everyone said AGM was the only way to go so that's what I bought. 3 years on them and still working like new when the engine went tats up. In that research I learned about the overuse of recycled lead.

As far as heat, give that some serious thought. Lithium batteries are definitely more prone to heat than regular lead acid, AGM, NmH, or AgZn. Years ago my father-in-law worked on a mini sub project for the Navy/DOD. 100% battery powered. They started with AgZn, which worked fine, no issues, but they decided the range wasn't enough, so they decided to change them out for Li. My father-in-law who had spent 6 years on subs minding batteries asked how they were going to cool them. The guys from Northrop looked at him like he had three heads. The same as the AgZn batteries they said. He said the center batteries would overheat and might catch fire. Well on sea trials exactly what he said would happen did and they almost lost the boat with the test crew twice. Ended up shelving the project (our tax dollars at work). Anyway, I'd definitely at least research the heat issue.

**Posted by BobE** 7/05/2024 6:49 AM

Bolted to Floor wrote:

Always look for the temperature rating of the insulation no matter where you buy any cable... even for a battery under the hood. It might be big cable, but a low temp insulation rating will reduce the amount of cranking amps making it to the battery.

Bolted to Floor – just a clarification wire insulation temperature limits; the issue with insulation is its ability to dissipate, and withstand, heat without degradation. If you’re referring to the National Electric Code (NEC) ratings, remember these are for specific installations, like “three wires in a raceway” or a cable open to “free air”, and the ability of the wire/cable to safely provide that rated current on a 24/7/365 basis.
For battery cables in a vehicle where high current draw occurs for a very short time, during starting the engine, the insulation temperature rating is not as critical. I believe any battery cable being sold will have the appropriate insulation for that application.

**Posted by Rufus68** 7/06/2024 8:21 AM

Nos681 wrote:
WOW are you S~ing me?
Smart battery or not.
It must be the latest craze down south with the heat.😜

Take a look at JEG’s and Summit to see small batteries that are available.
There are small AGM batteries that may fit your needs.
Some are lightweight and about 1/3 the cost.

JEG’s has Braille batteries for an example:

I think this AGM battery you posted, Braille B3121, looks like a very good option for his application. Cheaper and safer, what more can you ask?

**Posted by MS** 7/07/2024 10:13 AM

Stock battery fits fine if you trim the elongated part of the tray off. You just have to unbolt the top radiator bracket and push the radiator to the driver side to get the battery in and out. I use an Optima battery with rounded corners to avoid that. It goes in and out easily.

**Posted by RTM** 7/07/2024 11:53 AM

MS wrote:
Stock battery fits fine if you trim the elongated part of the tray off. You just have to unbolt the top radiator bracket and push the radiator to the driver side to get the battery in and out. I use an Optima battery with rounded corners to avoid that. It goes in and out easily.

With the AC lines coming through on that side, I’m not sure that would have been an option.

**Posted by KeithP** 7/07/2024 3:17 PM

RTM wrote:
MS wrote:
Stock battery fits fine if you trim the elongated part of the tray off. You just have to unbolt the top radiator bracket and push the radiator to the driver side to get the battery in and out. I use an Optima battery with rounded corners to avoid that. It goes in and out easily.

With the AC lines coming through on that side, I’m not sure that would have been an option.

I ran my AC lines under the battery tray.

**Posted by RTM** 7/07/2024 4:05 PM

KeithP wrote:
RTM wrote:
MS wrote:
Stock battery fits fine if you trim the elongated part of the tray off. You just have to unbolt the top radiator bracket and push the radiator to the driver side to get the battery in and out. I use an Optima battery with rounded corners to avoid that. It goes in and out easily.

With the AC lines coming through on that side, I’m not sure that would have been an option.
I ran my AC lines under the battery tray.

My issue is I made the parts I had which are designed for the drivers side work on the passenger side. Know what I know now about AC installation and my options I would have done things a little different. And at the time of installing the AC I was still going to put the battery in the trunk. There are some things I would different if I had known.