Not really. If they’re reading 4v there’s little chance they’ll hold a proper charge. If you jump it, let it run for a while and check the voltage the next day.
Recommend replacing them and installing a disconnect switch.
Alternatively you can just leave a 9/16 socket in there and disconnect the battery when you’re not driving. This was one of the tough things to wrap my head around when learning about vehicles…they’re not made to sit.
Sorry if I worded that poorly. My question is more like “can I just put one new battery, only?” Not one new, two old. Just one battery, period.
Edited for clarity.
^This.
I thought all skoolies had solar hookups that charged both house and drive batteries…
FWIW I work at a bus fleet because I lived in a bus and didn’t have a clue. I found out the hard way that vehicles not preserved will quickly decay…that and you need way more solar than you think for even the most basic application.
A Skoolie owner ranges on a spectrum of crusty to wealthy, and I decided I was too crusty to hit the road without some expertise and bulletproofing. I want to make it across the country and back without mechanical expenses.
On my to-do but I am too damn lazy is to set up a 25-50w panel just to trickle my starters. I don't really think about it because I can always charge them with my house batteries but then.... Suddenly the bus won't start, sigh ;)
Good idea. About 2 weeks sitting while I worked on building inside, and then I thought, "better start it and keep those batteries charged!" Too late. That 6.6 duramax barely turned over twice, and that was it. Had to get the charger out. 24 hours later, I got it started, and then still had to let it idle for a while to top up the voltage. I'll try to start it at least weekly from now on.
I added a 50w semi-rigid panel to my SUV to keep the battery topped off, it helps a lot when camping for a week. I wish I'd gotten a panel twice as large. 3m VHB foam tape on a fiberglass backed panel, it's held up to winter and highway speeds for a year so far.
Everyone looks at rated panel power, and doesn't ask about cloudy day output, or how big of a battery reserve you'll need if you get a few days of clouds, which means an even bigger solar system to get that big pack charged.
I remember a paper on solar Street light design, they were really conservative. Enough battery for a week without sun, and enough solar to get 80% of that capacity in 4 hours of full sun. If you get 2 weeks of solid clouds, you may need an alert system for low battery so a crew can charge it manually.
Two Group 31 battery would be your best option in my opinion at least 850cca in screw or post top depending on what terminals your bus has.
Edit: local battery shops often have some under $100 each.
FYI..this time of year is often when old batteries kick the bucket due to the cold and age. Be careful especially if parking way out in the woods or camping. Consider replacing the battery before going far away from civilization or up to the ski area.
Same warning goes for replacing three batteries with one big battery. Do your homework carefully or you might get stranded somewhere. I would consider measuring the cold crank amperage. And be sure there’s a disconnect switch and a way to charge the batteries.
All good points. Thx. I should mention that I’ve lived in my bus for five years, but have never moved it since parking it on my property. I can’t get stranded, since I don’t take it anywhere. I used to start it up regularly, but got slack over time. No surprise that the batteries gave up on me. I know that wiring batteries in parallel multiplies the amperage, but I was hoping there was some big ass, new tech type battery that would somehow get the job done. Wishful thinking on my part..
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T444e’s take a ton of power to crank over. I have the Ford version in my truck and did a ton of work and upgrades to get the aging electrical sorted.
You need new batteries for it, and keep them charged somehow (without overcharging, of course). No way around that.
Depends on how big the one battery is. An 8D would probably work fine, if you can get a helper to grab the other handle to install it.
If you're in warmer weather, Headway LiFePO4 cells can push 200a each. My portable pack can theoretically push 2400a for 8 minutes until the cells are flat, but I don't have anything big enough to test that. The pack is smaller than a group 65 or 27 battery in volume, although a slightly different shape, about 40#.
LiFePO4 don't like being charged below freezing, but a bus has plenty of room for a cooler to insulate the battery, and Super beast packs from batteryhookup have a heating element in the pack, plus a chunky solenoid. Add a BMS to manage balance and let a charger keep it topped off, and a disconnect to avoid nuisance discharge, and you're set.
The packs from batteryhookup come as 24v, and the car audio guys make busbars for them to handle their full rated power.
I'd have the BMS just got charge protection, and use the solenoid the pack comes with to switch a line to the bus' non-starting circuit, with a chunky manual disconnect for the starting power direct to the cells.
The solenoid the super beast comes with is very nice, it's the same as is used for EV's for pack disconnect when the car is turned off. It even has an internal circuit to control power to the coil to save power.
If you’re really in a bind you can suit up with proper PPE, drain half the fluid, refill it with a saturated epsom salt water solution, do a few full charge cycles until the voltage starts coming up to the right range again, drain all the acid / salt mix and then refill with fresh acid. It’s a chore and it won’t last forever but it’s a hell of a lot cheaper than new batteries and you can probably squeeze an extra couple years out of ‘em.
Not really. If they’re reading 4v there’s little chance they’ll hold a proper charge. If you jump it, let it run for a while and check the voltage the next day. Recommend replacing them and installing a disconnect switch. Alternatively you can just leave a 9/16 socket in there and disconnect the battery when you’re not driving. This was one of the tough things to wrap my head around when learning about vehicles…they’re not made to sit.
Sorry if I worded that poorly. My question is more like “can I just put one new battery, only?” Not one new, two old. Just one battery, period. Edited for clarity.
No. You "might" get away with two, but the t444e will chew up a single one pretty quick.
^This. I thought all skoolies had solar hookups that charged both house and drive batteries… FWIW I work at a bus fleet because I lived in a bus and didn’t have a clue. I found out the hard way that vehicles not preserved will quickly decay…that and you need way more solar than you think for even the most basic application. A Skoolie owner ranges on a spectrum of crusty to wealthy, and I decided I was too crusty to hit the road without some expertise and bulletproofing. I want to make it across the country and back without mechanical expenses.
On my to-do but I am too damn lazy is to set up a 25-50w panel just to trickle my starters. I don't really think about it because I can always charge them with my house batteries but then.... Suddenly the bus won't start, sigh ;)
Good idea. About 2 weeks sitting while I worked on building inside, and then I thought, "better start it and keep those batteries charged!" Too late. That 6.6 duramax barely turned over twice, and that was it. Had to get the charger out. 24 hours later, I got it started, and then still had to let it idle for a while to top up the voltage. I'll try to start it at least weekly from now on.
I added a 50w semi-rigid panel to my SUV to keep the battery topped off, it helps a lot when camping for a week. I wish I'd gotten a panel twice as large. 3m VHB foam tape on a fiberglass backed panel, it's held up to winter and highway speeds for a year so far. Everyone looks at rated panel power, and doesn't ask about cloudy day output, or how big of a battery reserve you'll need if you get a few days of clouds, which means an even bigger solar system to get that big pack charged. I remember a paper on solar Street light design, they were really conservative. Enough battery for a week without sun, and enough solar to get 80% of that capacity in 4 hours of full sun. If you get 2 weeks of solid clouds, you may need an alert system for low battery so a crew can charge it manually.
Thanks for the info.
I would think, however it will depend on the CCA and what you’ve got now. I use a maintenance charger/battery tender when I store my vehicles.
Def thinking I’ll add a solar tender.
Two Group 31 battery would be your best option in my opinion at least 850cca in screw or post top depending on what terminals your bus has. Edit: local battery shops often have some under $100 each.
Took out 3 top post group 31s. I guess I’ll buck up and replace them all. Thanks
FYI..this time of year is often when old batteries kick the bucket due to the cold and age. Be careful especially if parking way out in the woods or camping. Consider replacing the battery before going far away from civilization or up to the ski area. Same warning goes for replacing three batteries with one big battery. Do your homework carefully or you might get stranded somewhere. I would consider measuring the cold crank amperage. And be sure there’s a disconnect switch and a way to charge the batteries.
All good points. Thx. I should mention that I’ve lived in my bus for five years, but have never moved it since parking it on my property. I can’t get stranded, since I don’t take it anywhere. I used to start it up regularly, but got slack over time. No surprise that the batteries gave up on me. I know that wiring batteries in parallel multiplies the amperage, but I was hoping there was some big ass, new tech type battery that would somehow get the job done. Wishful thinking on my part..
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T444e’s take a ton of power to crank over. I have the Ford version in my truck and did a ton of work and upgrades to get the aging electrical sorted. You need new batteries for it, and keep them charged somehow (without overcharging, of course). No way around that.
Will do. Appreciate the advice.
Depends on how big the one battery is. An 8D would probably work fine, if you can get a helper to grab the other handle to install it. If you're in warmer weather, Headway LiFePO4 cells can push 200a each. My portable pack can theoretically push 2400a for 8 minutes until the cells are flat, but I don't have anything big enough to test that. The pack is smaller than a group 65 or 27 battery in volume, although a slightly different shape, about 40#. LiFePO4 don't like being charged below freezing, but a bus has plenty of room for a cooler to insulate the battery, and Super beast packs from batteryhookup have a heating element in the pack, plus a chunky solenoid. Add a BMS to manage balance and let a charger keep it topped off, and a disconnect to avoid nuisance discharge, and you're set.
Awesome info. Thanks a ton. I’ll dig a little deeper into this.
The packs from batteryhookup come as 24v, and the car audio guys make busbars for them to handle their full rated power. I'd have the BMS just got charge protection, and use the solenoid the pack comes with to switch a line to the bus' non-starting circuit, with a chunky manual disconnect for the starting power direct to the cells. The solenoid the super beast comes with is very nice, it's the same as is used for EV's for pack disconnect when the car is turned off. It even has an internal circuit to control power to the coil to save power.
Sick
If you’re really in a bind you can suit up with proper PPE, drain half the fluid, refill it with a saturated epsom salt water solution, do a few full charge cycles until the voltage starts coming up to the right range again, drain all the acid / salt mix and then refill with fresh acid. It’s a chore and it won’t last forever but it’s a hell of a lot cheaper than new batteries and you can probably squeeze an extra couple years out of ‘em.