Deep cycle battery for starting
 

Darn, the van needs a new battery.

This vehicle tends to see long periods (months) of not being used. I don't always remember to plug in a maintainer. So I replace a comprehensively dead battery every 2-3 years. Irritating.

I'm thinking of getting a deep cycle battery (RV/Marine) this time. Idea being it will survive being left to discharge for six months.

Good/bad idea?

Vanagon. Group 41 battery. Mild climate, always starts instantly.

I'm no expert, but I have four deep cycles in my motor home and the coach part has a regular truck battery. After months of sitting I can flip a switch and start the truck on those deep cycles long after the truck battery has gone dead. They are nothing special either, just Autozone off the shelf deep cycles.

Commit to the hard work and concentration of plugging in your maintainer. Why have to go through all this drama when your battery(ies) will last a maximum life time just by using your maintainer, which you've already paid for. My diesel truck now sits for pretty long periods without being started. I think I only drove it 5.5K miles last year. My last set of batteries lasted eight years. Keeping the charge up makes them last.

Solar Panel on the dashboard. They sell tiny (5-10 Watt) solar panels with a lighter plug on the end. It should have the diode installed. They produce little current, so they won't overcharge even without a charge controller. But they will keep a battery topped up all the time. If you are forgetful, hardwire it.

That's not the intention of a deep cycle. They're meant to have more amperage throughout the discharge cycle i.e. deeper cycle. Any lead acid battery does not like being left dead for long periods of time. Spend your effort on reminding yourself to plug the dang tender in. You know, set a buzzer on your phone or something...

I have a little solar panel, leave it on the dash, plugged into cig lighter. Didn't work. Grrr. Maybe I should put a slightly bigger panel on the roof and hardwire it. How big a panel would you go - want to be safe from overcharging.

I would buy a cheap disconnect switch that sits on one terminal and just cut the power when not used. Also, I would wire a small solar cell directly to battery terminals just to fend off self-discharge current.

https://www.amazon.com/dp/B017K6PH1S/ref=asc_df_B017K6PH1S5153287/?tag=hyprod-20&creative=395009&creativeASIN=B017K6PH1S&linkCod e=df0&hvadid=198064505516&hvpos=1o1&hvnetw=g&hvran d=18220671552439794821&hvpone=&hvptwo=&hvqmt=&hvde v=c&hvdvcmdl=&hvlocint=&hvlocphy=9015815&hvtargid= pla-322799124658

Guaranteed to work, $32. Just don't park your van in the garage.

Does your car cigarette lighter work with the ignition off? 5-10 Watts should do it. A 0.5 amp trickle charger makes maybe 72 Watt-hours per day. A 10 Watt Solar panel will do ~50, depending on location.

Lead acid batteries lose ~3% per month. Even a tiny solar panel should keep it topped up. Check to make sure there isn't a relay which shuts off the outlets when the ignition is off.

Only thing on the solar panel, I would MAKE SURE you have a 2 amp fuse inline with the 10 Watt solar panel. If the wiring shorts, I want that fuse to blow.

My John Deere diesel utility tractor has the same (fairly small sized) marine deep cycle battery in it from 2009 that I bought new then. I start it almost every day, and sometimes in subzero temps. I keep thinking I will have to replace it , but it hasn't given me ANY problems so far.

^^^^This is the correct answer^^^^^^^^^Automotive batteries will stay 'lit' for a looong time if: A) There is no parasitic draw above 50 Ma B) The case and terminals are clean and free of moister and debris.

Which leads me to another little known fact. Electrons inside the battery cells escape through the vents and the case. The more premium (cost) of batteries - the thicker the case is..........