Battery type for inverter

[Rvnewbie84]

Hello, A little advice needed. I bought a modified sine wave inverter and connected it to a 12v mower battery from Lowe’s but it stopped working early on.
My question is, is getting a car battery from an AutoZone and using that with my 750 watt inverter, better?

Thanks for the replies

 

[marc2912]

I’ll let much smarter people follow up but my understanding is that you need a deep cycle battery, a car battery is meant to push high amperage quick while a deep cycle battery is long steady power discharge. They’re also meant much more for charge and discharge. My coach for example has 8x 6volt deep cycle battery with every pair in series to go to 12v and the 4 groups in parallel.

I still don’t fully understand what the + is with using this approach vs using 12v batteries all in parallel but at least this should give you a research starting point.

 

[Rvnewbie84]

I’ll let much smarter people follow up but my understanding is that you need a deep cycle battery, a car battery is meant to push high amperage quick while a deep cycle battery is long steady power discharge. They’re also meant much more for charge and discharge. My coach for example has 8x 6volt deep cycle battery with every pair in series to go to 12v and the 4 groups in parallel.

I still don’t fully understand what the + is with using this approach vs using 12v batteries all in parallel but at least this should give you a research starting point.

Thanks for your reply, definitely helpful!

 

[Bob K4TAX]

One needs to understand the current demand for the inverter vs. the current capacity of the battery. A 750-watt inverter under full load will draw some 75 amps from the battery. A 100Ah battery can be discharged to about 50% capacity without damage. This equates to 50/75 or about 30 minutes of time. Of course, less load demand on the inverter will mean longer battery capacity life.

If one plans on running an inverter, additional battery capacity is strongly suggested. For the system using 6V batteries in series and then the 6V pairs/series in parallel, this is to attain more Ah battery capacity. For the person with the 8 x 6V batteries, assuming a 100Ah rating for each battery, he has about 800 Ah of battery capacity. They should be able to run a 750-watt inverter at full load safely for about 5.5 hrs.

I'd say your lawn mower battery is 250 CCA this is about 34Ah capacity. CCA / 7.25 = Ah. With this size battery, I can understand why your 750-watt inverter stopped working.