One battery vs 2 independent or 2 parallels

Hello, y’all. Hope all is well in this sunny weather. I currently have two batteries to run my gear. Both are Deep Cycle. One starts the 6-ish gpm cold water and the other starts the 8GPM HW and run’s the Soft Wash.

I am only part-time working after my day job and on the weekends. Trying to figure out if I should go down to 1 battery for all 3, keep both batteries independent (the cold water gets its own), or wire both batteries in parallel to run all of it. I’d rather wire the two batteries in parallel but wonder how dual charging would work (when I run both washers). I assume the bigger washer would charge faster than the smaller. If I can wire the batteries in parallel I’d never have to worry about the soft wash system and could charge all at once (with deep cycle charger).

Anyone else have multiple batteries? How do you have it setup? Thank you for your help.

I keep my 8gpm on its own battery. My softwash system is two group 24’s in parallel. Can run all day no problem. Find out if your bigger machine charges at 16 (I think it’s 16 at least) or 20 amps. If it’s 20 you should be fine. My gx690 has the 20amp rectifier so it could probably maintain a good charge on two group 24’s but I just prefer for it to have its own battery.

I run the one for my washer and 12v in parallel. Machine keeps both topped out. Have never ever had to charge either in 20 months.


Do you clean roofs or just general stuff? I hadn’t thought about the machine charging the batteries.

I’ll go one further: I have one battery in total (a marine deep cycle group 28, IIRC) for starting the truck, starting the machine, and operating the wfp pump and reels.

I put a battery tender on it every few weeks, and it’s usually around 80-90% when I do. Machine does a pretty good job of keeping it topped off.

Yes, I like to live dangerously…

If you don’t already, you should keep a jump pack in the truck just in case. You don’t want to have to call AAA and wait on them to show up when you could just jump it and roll on.

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