Jumping my unit after sitting all winter
- Thread starter Rob11
- Start date
CoveredWagon
Well-known member
Jumper cables. I've done this when a park lost power and batteries ran low.
taskswap
Well-known member
If y'all want a modern improvement on the usual hassle, lithium "jump packs" are really cheap these days on Amazon and are a lot easier. Most are like $60-$80, only need to be recharged/topped up once a year, and store very small compared to jumper cables. I haven't used one to operate my landing gear but I have to run out my slides which takes a lot of juice, and one pack will easily do that several times on one charge.
It's really nice not having to inch your truck super close under your king pin, you can self-jump your truck too if need be, and if somebody else at a campground needs a jump you can just hand it to them and not have to drive over to help them out. We have one in every vehicle's trunk now.
It's really nice not having to inch your truck super close under your king pin, you can self-jump your truck too if need be, and if somebody else at a campground needs a jump you can just hand it to them and not have to drive over to help them out. We have one in every vehicle's trunk now.
taskswap
Well-known member
I just found another use for a jump pack BTW. I recently replaced my camper batteries with lithiums (plus solar). I'm sure you all know they have built-in management features like cutting off charging if they go below freezing since that ruins them. Well apparently the BMS in the battery I bought has a low voltage cutoff which disconnects the battery since over-discharging them is bad too. Good so far, all expected.
What I didn't expect is that this BMS won't turn the battery back ON until it sees a certain amount of recharge. But my solar charge controller was trying to be too smart, and thinking there was no battery connected so it wasn't trying to charge anything either. (The battery was completely cut off so I think the charge controller was "seeing" 0V downstream and assuming there was no battery at all.) So despite 3 days of sun after the discharge event, the battery was still flat when I came out here.
I hooked the jump pack to it for about 5 seconds and that kicked the charge controller on, and as soon as that was on, the battery came on again too because the BMS knew it was being charged.
It's sort of a similar situation to jumping a car battery, I suppose, but with an odd twist on the events that led to it. Just thought some folks might be interested to know since so many are switching to lithiums now. With a lead acid battery it'll happily drain down to 9-8V or even lower, which does plenty of damage, but at least you'll get a dim light to turn on and if there's a charger somewhere, it'll try to charge. But without the jump pack my whole power system would have been offline - these batteries have no "switch" to force them to turn back on. It takes a high voltage signal to do it.
What I didn't expect is that this BMS won't turn the battery back ON until it sees a certain amount of recharge. But my solar charge controller was trying to be too smart, and thinking there was no battery connected so it wasn't trying to charge anything either. (The battery was completely cut off so I think the charge controller was "seeing" 0V downstream and assuming there was no battery at all.) So despite 3 days of sun after the discharge event, the battery was still flat when I came out here.
I hooked the jump pack to it for about 5 seconds and that kicked the charge controller on, and as soon as that was on, the battery came on again too because the BMS knew it was being charged.
It's sort of a similar situation to jumping a car battery, I suppose, but with an odd twist on the events that led to it. Just thought some folks might be interested to know since so many are switching to lithiums now. With a lead acid battery it'll happily drain down to 9-8V or even lower, which does plenty of damage, but at least you'll get a dim light to turn on and if there's a charger somewhere, it'll try to charge. But without the jump pack my whole power system would have been offline - these batteries have no "switch" to force them to turn back on. It takes a high voltage signal to do it.
