Antigravity 4cell on CB450?

1294 Views 7 Replies 5 Participants Last post by 3364, May 19, 2022

Minch

Discussion Starter · Apr 20, 2022

I’m trying to decide between the antigravity 4cell and the 8cell. I have a 73 CB450 and I want to use the electric start for it. Will the 4 be enough? I’d prefer the 4 over the 8 due to the size.

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The number of cells is probably the least of your worries. What sort of regulator did you convert it over to?

If you're still running the stock charging system, a lithium battery is a bad idea. Modern battery tech does not play well with old school charging systems. Even with a modern regulator, some battery companies claim their lithium batteries should not be used on old school bikes because of the variation in the charging voltage, even if it is under the maximum allowed. And many modern aftermarket regulators specifically say they aren't to be used with lithium batteries.

At the very least you need a MOSFET regulator. The re-start antigravity batteries apparently have a BMS built in but even that isn't a fail safe. I don't know which batteries they have are 4 cell and which are 8 cell but if you're looking at the micro-start stuff with no BMS you're rolling the dice. You can kill it by running it down too far, or by putting too many volts into it. For a lithium battery, the max charging voltage is somewhere around 14.9. Does your regulator always keep the voltage below that at all rpm? Are you sure? Is there any stray drain on your bike that will run the battery down as it sits? Get it wrong and the battery is shot. No recharging. It's done. Buy a new one.

From the anti-gravity site:

ATZ7-RS Lithium Motorcycle Battery

Hi-Power lightweight ATZ7-RS lithium powersports battery with RE-START Technology (built-in jump-starting). Replace YTZ7S, YTZ5, more. 150 CA.

antigravitybatteries.com

The good news is, Anti-Gravity uses lithium iron which isn't as prone to flaming up as lithium ion batteries are. So if you overhcharge one, you'll likely only get some impressive arcing and really nasty smoke as it melts. It probably won't actually start burning.

IMHO a battery with no built in BMS doesn't belong in a bike. I say that as someone who's melted one down that HAD a BMS, but when you completely lose the regulator things get crazy. This took over 60 volts to melt down but a '91 Ducati has no problems doing that when things fail. With no BMS, 16 volts could eventually lead to this.

I'm running a lithium battery in an older bike that probably shouldn't be using one. I'm also running a MOSFET regulator and a volt meter. IMHO you need both of those, along with a battery that has a built in BMS to run a lithium battry in on old bike. And even then it's not "best practice".

If you must use a lithium battery;
Get a modern regulator
Install a volt meter
Don't use a battery with no built in BMS
Don't bitch when it still goes wrong.

Rough guess is you'll have about $350 into putting the first lithium battery in there. Try to cut corners and you'll have about $500 into it with the second one. Or you'll save money and find room for an AGM the second time around. Ya might want to find room for an AGM now and avoid all the costs/time of the lithium...

And what makes me think any of this can happen??? (NSFW language)

http://teamyikes.com/851/EarthX.mov

To answer your original question (sort of), buy the smallest Re-start version they have. It should turn it over fine. If it doesn't, cowboy up and use the kickstart.

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Minch

Discussion Starter · #3 · Apr 20, 2022

DesmoDog said:
What sort of regulator did you convert it over to?

If you're still running the stock charging system, a lithium battery is a bad idea. Modern battery tech does not mix with old school charging systems. Even with a modern regulator, some battery companies claim their lithium batteries should not be used on old school bikes because of the variation in the charging voltage, even if it is under the maximum allowed.

At the very least you need a MOSFET regulator. The re-start antigravity batteries apparently have a BMS built in but even that isn't a fail safe. I don't know which batteries they have are 4 cell and which are 8 cell but if you're looking at the micro-start stuff with no BMS you're playing with fire. You can kill it by running it down to far, or by putting too many volts into it. For a lithium battery, the max charging voltage is somewhere around 14.9. Does your regulator keep things below that at all rpm? The good news is, Anti-Gravity uses lithium iron which isn't as prone to flaming up as lithium ion batteries are. So if you ignore everything I've said and overhcharge one, you'll likely only get some impressive arcing and really nasty smoke as it melts. It probably won't actually start burning.

A battery with no built in BMS doesn't belong in a bike IMHO. I say that as someone who's melted one down that HAD a BMS built in, but when you completely lose the regulator things get fun. This took over 60 volts to melt down but a '91 Ducati has no problems doing that when things fail. With no BMS, 16 volts could eventually lead to this.

I got the ricks motor sports reg/rec that goes to about 14.2. I just wanted to know if the 4cell is strong enough to start my 450.

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DesmoDog

· #4 · Apr 20, 2022 (Edited)

Minch said:
I got the ricks motor sports reg/rec that goes to about 14.2. I just wanted to know if the 4cell is strong enough to start my 450.

Well in that case you're about five steps ahead of most newbs who post here.

I have no idea what the "4 cell" battery is. But like I said, if it doesn't have built in BMS it's a bad idea.

EDIT: I just googled it, the 4 cell looks like a previous model, I don't see it on the Anti-Gravity website but do see it at Revzilla (though it's sold out)

I think it's still available as a "Small Case" battery through Anti-Gravity, but it doesn't have BMS. It should be big enough to turn the engine over but with no BMS you're using it at your own risk.

Put it somewhere it won't take other things out if it melts down. The smoke is NASTY and you will never get the stench out of seat foam. And the arcing will ruin any paint/plastic in the general vicinity.

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rich46

· #5 · Apr 20, 2022

Minch said:
I got the ricks motor sports reg/rec that goes to about 14.2. I just wanted to know if the 4cell is strong enough to start my 450.

Minch,
I would try E-mailing the battery manufacturer. You will need to be able to tell them the cranking amps needed and the alternator output. Would also be nice to give them measurement for the space you have. . We have doing this by direct contact with the US supplier for one of these companies for about ten years now. We are using lithium batteries in all our racers from a 1980 Moto Guzzi to a 2015 Yamaha R-6 with only one fail. The fail was with my Triumph 2004 Thruxton daily rider. The Triumph cooked two batteries in a row. Back to lead/acid.

I will tell you that one of the smallest lithium batteries that I could find starts a V-twin Superhawk engined bike over and over and has for the last four years. Now this engine is always in top tune so it starts quickly but as long as you flip the key to on and let it warm up before you try and spin the starter it cranks right up turning over rather quickly.

One last thing as I am in no way the authority these super light batteries. I always put the bikes on a charge when they are parked (street bike, race bike, doesn't matter. Nor does it matter how long they are going to sit) and I always use a lithium specific charger on the lithium ones, Just saying use the right tool for the job.

Rich

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TrialsRider

· #6 · Apr 20, 2022

Minch said:
I’m trying to decide between the antigravity 4cell and the 8cell. I have a 73 CB450 and I want to use the electric start for it. Will the 4 be enough? I’d prefer the 4 over the 8 due to the size.

On a warm summer day with a full charged fairly new extremely expensive battery, no problem cranking it over if the bike starts and runs well.
Cold weather or an engine that doesn't turn over easy as it should or add a bunch of lights and a horn, then that 4-cell might leave you stranded.

That's an awful expensive way to save a couple of pounds on a motorcycle that was built very heavy to begin with and it's hard to imagine you can't find room for a full size battery in that steel hoop frame. I'd be putting a lead acid battery in that ride and put the extra 100 bucks into tires or a chain or something useful, the tiny battery is going to buy you nothing.

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rich46

· #7 · Apr 22, 2022

TrialsRider said:
On a warm summer day with a full charged fairly new extremely expensive battery, no problem cranking it over if the bike starts and runs well.
Cold weather or an engine that doesn't turn over easy as it should or add a bunch of lights and a horn, then that 4-cell might leave you stranded.

That's an awful expensive way to save a couple of pounds on a motorcycle that was built very heavy to begin with and it's hard to imagine you can't find room for a full size battery in that steel hoop frame. I'd be putting a lead acid battery in that ride and put the extra 100 bucks into tires or a chain or something useful, the tiny battery is going to buy you nothing.

Batteries and the people who use them;
Just one other plus on the modern lithium batteries (here I will admit that we get a crazy good deal on our batteries thus why I've not mentioned a brand) is that you can put them almost anywhere pointing in any direction and as long as you get the positive hooked to the red wire you're good to go.
Like anything new you need to learn their unique issues such as they work better when given time to warm up but I for one think the plus side should be considered.
Price wise when I compared them to the top of the line L/A batteries they aren't all that bad. Remember cheap Lead/acid leak and need distilled water that needs checking. LOL also you need to consider how much less it cost to ship a lithium 1.2 lb. battery.
Rich

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3364

· #8 · May 19, 2022

Minch said:
I’m trying to decide between the antigravity 4cell and the 8cell. I have a 73 CB450 and I want to use the electric start for it. Will the 4 be enough? I’d prefer the 4 over the 8 due to the size.

I ussed to have a 92 GSXR that had a moped battery mounted to the contershaft cover. I did live in Hawaii though. And that bike started instantly.

I suspect if your bike starts and runs well you could get by with one of these but why not get an 8 cell. I ran 2 of the 4 cells on a bike before due to space constraints. If you do this just be sure you understand the difference between parallel and series battery wiring.

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