What is the best out there?

Solar, or you asking about a plug-in type to top them off??

Plug in type

Many year ago I bought several varieties of cheap to pricey "BatteryMinders". Not sure if they still sell them but I have been very happy with them. They will top off good batteries. If the battery is bad, it will tell you. I stopped hanging on to 'iffy' batteries. If it doesnt take a charge or the charger balks, it goes in trash or as a core.

https://www.amazon.com/NOCO-GENIUS1-Fully-Automatic-Temperature-Compensation/dp/B07W46BX31/ref=asc_df_B07W46BX31/?tag=hyprod-20&linkCode=df0&hvadid=693334113981&hvpos=&hvnetw=g&hvrand=3494410178096022096&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9028453&hvtargid=pla-851914189655&psc=1&mcid=8d2e4fb0572534be9eb700c331de8a19

That one is pretty nice, for $29. Does 6v and 12v, and will let you "force charge" some batteries that are WAY down (some "automatic" chargers will simply "ignore" a battery that is below a certain voltage, and will not charge them).

For just plain "cheap", this:
https://www.harborfreight.com/12v-automatic-battery-maintainer-59000.html?event_id=183619&utm_source=google&utm_medium=cpc&utm_campaign=12144811130&campaignid=12144811130&utm_content=150898456447&adsetid=150898456447&product=59000&store=3087&gad_source=1&gbraid=0AAAAADAHb4eh4E3dflLVDVEPMCJW94gsL&gclid=EAIaIQobChMIvKa02YeniAMV387CBB1cjRgkEAQYBSABEgJIc_D_BwE

It's half the price of those cheapie feeder battery chargers, and works as well (they're all 400-500 mA chargers). Won't do 6v, though (for those that might need that function).

I picked up the HF one yesterday and it seems to be doing good

Good to hear. Lots of folks will tell you how they got 4 years out of their batteries, etc, etc. Personally, I only get about 2 years out of them, sitting in the feeder, solar charged, working year-round (in 20-105 degree weather). After that, they're a complete crap shoot.

I usually write the date that I got them in sharpie, on the side, and replace them at 2 years. Not worth ruining a "sit", just to try and put off spending $10 (6V) or $20 (12V) for a few extra months or a year, on a new battery.

I think I am done with solar panels and raccoons.

Buying more interstate batteries today and keeping them rotated and charged.

Well, that'll work, too. Raccoons are hell on solar panel wiring, unless it has the metal flex conduit. Even then, they sometimes manage to find a way to destroy them…

AgsMnn said:

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What is the best out there?

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I got those on sale the other day. Still a good deal at regular price. You can charge 12 or 6 volt… 4 at a time

https://a.co/d/2LjyP4y

If you have a standard 12 volt auto battery charger use it to charge your rechargeable 12 volt feeder batteries. Or use a cheap Harbor Freight 2 amp trickle charger.

SanAntoneAg said:

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If you have a standard 12 volt auto battery charger use it to charge your rechargeable 12 volt feeder batteries. Or use a cheap Harbor Freight 2 amp trickle charger.

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You'll trash them if it's not a low amp trickle charger. Or at least that's been my experience. So be careful with the high amp chargers.