Yams/Suzukis and Lithiums

[boscoe99]

Can I get a show of hands from those that are using a lithium starting battery with their Yamaha or Suzuki please? Model of the motor would also be appreciated.

Thanks.

 

[Toyelectroman]

I thought I heard that lithium batteries don't have enough cold cranking amps to always start the motor. Hope that is not true because I would love to switch out to lithium

 

[99yam40]

I have heard charging them off of an outboard is a problem.

not sure I want something that can burst in to flames and impossible to put out a good thing

 

[pgandw]

I have heard charging them off of an outboard is a problem.

not sure I want something that can burst in to flames and impossible to put out a good thing

Charging fully off an outboard alternator depends on the programming of the regulator. You can get around this with a DC-DC charger that is designed to properly charge LiFePO batteries.

Lithium batteries currently come in 2 different battery chemistries. Lithium-ion is more power dense, and is used in phones, power tools, and most electric vehicles. If case gets cracked, battery can catch fire when exposed to oxygen, and is very difficult to extinguish.

LiFePO (lithium iron phosphate) is a very different chemistry, and is very stable. It is used for 6, 12, 24, 48 volt lead acid replacement, I have never heard of one catching fire. It is used in RVs and boats and golf carts with an enviable safety record. While not as energy-dense as lithium ion, LiFEPO batteries are 1/3 the weight of lead acid, and have proven life spans of 10X the number of battery cycles (typically in the thousands depending on application). LiFePO is NOT usually a good substitute for starting high hp motors because the BMS holds loads to under 50A, or 100A on the better BMS, but is very well suited for house batteries and running trolling motors.

 

[cyclops222]

LIFEPO4 are excellent batteries. BUUTT
Those fully charged ones can cause a fire in a very unexpected way. A starter motor that can not spin freely will pull loads of amps. Far more than Lead Acid ones could ever deliver. So if you have loose connections. Corroded connections. Jamming starters for any reason ? Be warned the LIFEPO4 is going to deliver WAY more amps than a same rated Lead Acid battery. LIFEPO4 CAN overheat starter cables to the point of the insulation dripping off. And now bare Copper wire strands glowing hot can short out many other wires. If pressed together. They are great in CAREFUL thought out and very cautious routing of the cables. A friend had all 4 100 amp rated batteries in parallel fail. When they became connected to a STALLED Golf Cart motor in a boat. No fuses were used in any battery cables.
Be super cautious with Lithium in a boat. You will not want to leave a boat because you have a electrical short circuit fire in it.

 

[pgandw]

LIFEPO4 are excellent batteries. BUUTT
Those fully charged ones can cause a fire in a very unexpected way. A starter motor that can not spin freely will pull loads of amps. Far more than Lead Acid ones could ever deliver. So if you have loose connections. Corroded connections. Jamming starters for any reason ? Be warned the LIFEPO4 is going to deliver WAY more amps than a same rated Lead Acid battery. LIFEPO4 CAN overheat starter cables to the point of the insulation dripping off. And now bare Copper wire strands glowing hot can short out many other wires. If pressed together. They are great in CAREFUL thought out and very cautious routing of the cables. A friend had all 4 100 amp rated batteries in parallel fail. When they became connected to a STALLED Golf Cart motor in a boat. No fuses were used in any battery cables.
Be super cautious with Lithium in a boat. You will not want to leave a boat because you have a electrical short circuit fire in it.

Actually, the BMS (Battery Management System) will prevent drawing more current out of the battery than the battery can handle. BMS for a 100AH LiFePO battery is typically rated at 50 amps, 100 amps on an upgraded model. Trying to draw more current than that causes the BMS to shut the battery off - and very quickly.

Which is why LiFePO batteries can't be used as starting batteries for high HP motors - the starter motors for big motors draw too much current and will cause the BMS to trip the battery off line. Your friend in a golf cart had the batteries trip off line instead of starting a fire.

I have experienced a battery fire with lead-acid batteries that were paralleled without fuses. I have seen the cherry red parallel cables and the beautiful blue burning hydrogen from the vents. Had to put the fire out by cutting one of the paralleling cables - after the top of one of the lead acid batteries had its top blown open. In a LiFePO installation, the internal BMSs would have taken the batteries off line before any melting insulation happened. You cannot draw more out of the LiFePO battery than the BMS allows. And the fuses for the wire should be sized to protect the wire if the wire is rated for less than the BMS.

There are lots of scare stories about "lithium" batteries. But dig to the bottom, no known fires from LiFePO batteries. Lots of improper or no fusing for wire size. Not enough matching of BMS capacity to load.

Fred W

 

[cyclops222]

But not all batteries have strong enough B M S .
Is there a USA law that requires Powerful and reliable BMS systems for all sizes of batteries ?

 

[pgandw]

But not all batteries have strong enough B M S .

Correct for starting a high hp motor with a LiFePO. For preventing battery meltdowns and fires, any standard BMS will shut the battery down before damage to the battery or drawing excessive current (BMS controls maximum current out of or into an LiFePO battery). A "weaker" BMS is rated for less current in or out of the battery, and therefore shuts the battery down sooner in the face of a high load or charge current.

A whole lot better than a lead acid battery which has no regulation of maximum current into or out of the battery.