It's always hard to keep the batteries up on equipment that sits for long periods. I found a solar battery maintainer/desulfinator that's working well for me.
Solargizer from Pulse Tech like these:
(I don't sell these, just examples I've found online)
https://www.ebay.com/itm/274330466964
https://www.easternsurplus.net/PartDetails/7209/ALL-5225-24V-Solar-B...
These two are 24v that I'm using on my D6c dozer and a 5-ton military truck but there are 12v models.
Direct from the company they are a little pricey but they can be found on eBay and other places for much cheaper. The military uses the 24v versions so can be found surplus.
For the dozer I stick it to the top of the brush guard with magnets, and when running the machine I pull it off and stick it under the canopy to keep from tearing it off with tree limbs.
Solargizer from Pulse Tech like these:
(I don't sell these, just examples I've found online)
https://www.ebay.com/itm/274330466964
https://www.easternsurplus.net/PartDetails/7209/ALL-5225-24V-Solar-B...
These two are 24v that I'm using on my D6c dozer and a 5-ton military truck but there are 12v models.
Direct from the company they are a little pricey but they can be found on eBay and other places for much cheaper. The military uses the 24v versions so can be found surplus.
For the dozer I stick it to the top of the brush guard with magnets, and when running the machine I pull it off and stick it under the canopy to keep from tearing it off with tree limbs.