Can I Start My Onan Generator With Lithium Ion Batteries

[Hblick48]

Planning on upgrading to Lithium Ion batteries. I've read that you can't use them to start an on board generator. Is this true? If so, what do you do to start the generator?

[Playhouse]

Hmmm. That doesn’t sound right. The gen just needs 12v with enough cranking amps, right?

[Foldbak]

Not true. They can do anything a lead acid can and more!

[R.S.O'Donnell]

You absolutely can:

https://youtu.be/rPibD6CBK_I

[agoodwin3940]

Battle Born Batteries FAQ section answers your question for their products. Other manufactures may have different answers.

From Battle Born: Our battery is designed as a deep cycle storage battery and doesn’t offer the cold cranking amps most applications require for starting.

Multiple batteries connected in parallel can be used in an emergency situation, but prolonged use in starting applications can result in a diminished capacity or damage to the battery’s management system.

The continuous discharge rate of our batteries is 100 amps, 200 amps for 30 seconds and higher loads for ½ second. Cold cranking applications typically exceed 200 amps which will cause our batteries to shut off.

The manual (page 29 under specifications) for my Onan QG7000 states minimum battery capacity is 450 CCA @ 0 degrees F.

The way I’m reading Battle Born’s recommendations, you would need 3 of their 100 amp hour batteries, which can be pushed to 200 amps for 30 seconds, to meet Onan’s minimum CCA requirements.

[Da40flyer]

We have the factory Onan generator and swapped out the factory LA battery for a Battleborn 100Ah. The battery has never had a problem starting the generator.

The catch...
We only have a 200W solar panel. The problem we encountered when we boondocked was that we had to monitor the battery life over night to ensure enough power remained to be able to start the Onan in order to be able to recharge the battery. Therfore, we never let the Battleborn get below 50%.

This quickly became a hassle, so I installed a lightweight Braille AGM start battery for the Onan with a trickle charger. Now we can use all of the Battleborn's capacity and still be able to start the Onan and recharge the Battleborn at any point. The total weight of the two new batteries is still less than the original LA.

[Hblick48]

Update: I ended up buying 280AH LiFePO4 battery, 40 amp MPPT charge controller (I have 300 watts solar but my old controller can't handle lithium). Also bought a LiFePO4 motorcycle battery and a Xantrex Digital Echo Charger. It will maintain the motorcycle battery from the 280A battery.

The main reason for the separate motorcycle battery is so I don't have to worry about leaving enough juice in the 280A to start the generator.

Will be installing in a few days, I'll update how everything works.

[Hblick48]

Here's a picture of the final installation. There is a battery monitor sitting on top of the battery. I've since located it inside. The generator starts fine, and the Xantrex charger works as advertised. I ran the Diah receiver and TV all day. Battery never went below 100%, so I'm generating more power than being used. I am going to install another 200 watts of solar panels for those days without blazing sun.

[Foldbak]

Originally Posted by Hblick48

Here's a picture of the final installation. There is a battery monitor sitting on top of the battery. I've since located it inside. The generator starts fine, and the Xantrex charger works as advertised. I ran the Diah receiver and TV all day. Battery never went below 100%, so I'm generating more power than being used. I am going to install another 200 watts of solar panels for those days without blazing sun.

A bit over kill....but OK. Best upgrade is more solar panels, more controller capacity and more AH's. You're there!