Need a battery to start my Onan, 460 cca min, dual-purpose?

SCADAMAN29325 wrote:
Using chassis battery to start house generator.

Since I don't have a house battery yet, it may help with deciding on a house battery that does not need to start the generator.

Hmmm...

If your genny starter motor is already wired to the house battery location (obviously the genny output is wired to the house system/converter) there is zero need to change that. Any deep cycle/dual purpose 12V or a pair of 6V batteries will start the generator without issue.
It will not draw more amps than a deep cycle can produce reliably.
By the same token, if its somehow wired to the starting battery (for the engine/coach) that is fine too.

Grp 27 wet cell : economical , will work well and charge using the converter you have.
I have used these batts and they worked fine for the 4 years i had them. Two grp 27’s will give you 160 ah and enough cca’s to start your Onan genny .
Correct me if I'm wrong , AFAIK, the Onan’s are usually factory wired off the house bank .
While off grid, these two batts ran my 25,000 btu furnace just fine throughout the winter . I was able to get through the night and the next morning with no issues.



https://www.lowes.com/pd/Deka-12-Volt-800-Amp-Marine-Battery/50183759?cm_mmc=shp-_-c-_-prd-_-sol-_-bng-_-PLA_SOL_146_Riders-Powersports-Chore-_-50183759-_-Online-_-0-_-0&msclkid=1b6d5b9dedea1aa1b46a38ef764b4f8f&gclid=1b6d5b9dedea1aa1b46a38ef764b4f8f&gclsrc=3p.ds

SCADAMAN29325 wrote:

time2roll wrote:
Please check that the generator charges both the house and chassis battery while running.

Is this as simple as checking the voltage on the house battery terminals, with engine started?

Sorry to be so ignorant about this, but just want to make sure I understand.

Thanks.

YES!

12.8 or less is probably not charging. 13.2+ is charging.

Check separately with the engine running and then with just the generator running. Post the results if there is any question.

Try Sam's Club for pricing, and they have different options for house/coach batteries, including deep cycle, and dual purpose, in both FLA/GEL/AGM. Not sure if they sell lithium yet, but they probably do. Some of their brands like Duracell, are actually made by battery companies like East Penn and Trojan. I started using one of their dual purpose AGMs as a chassis battery a few years back, and it's been better than a typical starting battery, as it takes a lot of abuse and still works. Something like that would probably work as either chassis or coach for you.

You might consider using a deep cycle battery for the house which is generally preferred. Or a marine deep cycle which is a compromised starting battery. Deep cycle batteries will start a gen, but they do cost more being a better battery.

There are various reasons on which bank and batteries to use. Based on what you've posted I'd suggest doing what is easiest and best for you to start as you can make changes down the road as desired. Flooded batteries seem to be the best short term and lowest cost for you.

SCADAMAN29325 wrote:

time2roll wrote:
Please check that the generator charges both the house and chassis battery while running.

Is this as simple as checking the voltage on the house battery terminals, with engine started?

Sorry to be so ignorant about this, but just want to make sure I understand.

Thanks.

Yes. With both batteries slightly discharged start the engine and the voltage for each should start to increase. There may be some delay on the house battery voltage rise and/or different voltage on the two banks depending upon the type of isolator.

time2roll wrote:
Please check that the generator charges both the house and chassis battery while running.

Is this as simple as checking the voltage on the house battery terminals, with engine started?

Sorry to be so ignorant about this, but just want to make sure I understand.

Thanks.

SCADAMAN29325 wrote:
Using chassis battery to start house generator.

Since I don't have a house battery yet, it may help with deciding on a house battery that does not need to start the generator.

Hmmm...

I agree with using the chassis battery to start the generator. Please check that the generator charges both the house and chassis battery while running.

Not sure what the house needs are but a standard low cost 12v deep cycle from Walmart or Costco will serve fine for a year to get this sorted out.

Gong with lithium and other batteries may require replacement of your converter. Just another cost you need to consider.

enblethen wrote:
Why not stay with lead acid?

That's a big maybe, since I really don't need to create another project right now.

Thanks!