battery maintainer

For those whose trucks sit.

What do you use?

I was thinking of a HF @ .750 milli amps. Works fine on my motorcycle but that's only 300 amps. Worked good enough to charge my son's car overnight that he could start it without a jump.

But. We're talking 3000 amps on the semi. Autozone has 1 Amp and 2 Amp floaters.


????

 

I use a harbor freight thunderbolt 25 watt solar panel tossed up on the dash and their 100 watt charger you can direct wire or plug into a cig lighter/power port. 85 bucks for both if they're not all on sale at the time. But, not having to deal with a drop cord or opening up the battery box is nice. At full power during the day 20watt at 12 volt is only 2.5 amp. Unless you have a serious draw I think any maintainer would work just fine.

 

if its just being used as a maintainer it's shouldn't have to be very high amperage should it? just enough to replace any small draw or loss. if you are losing more find your issue

 

You need at least a two amp battery maintainer on a modern semi truck to keep the batteries topped up.
With all the computers on board there are some systems that are at least in the sleep state drawing a small amount of current with the key off.
You didn’t mention the truck model. Freightliner Cascadia guides says a maximum parasitic draw of one amp continuously is acceptable and expected.
That’s why it has a sticker by the battery disconnect switch to shut if off if the truck is parked for more than a weekend.

 

I installed 3 new batteries 3 months ago and measured draw at .4 positive .25 negative.

.15 draw

18 Pete.


.75 amps would cover it. I'm just concerned with the 3000 amps to maintain. There's no shutoff switch.

 

Put a cutoff switch on the truck. I leave my truck parked in my driveway for weeks at a time with the batteries cut off.

 

Volvos have one behind the fairing (if it has one) under the drivers seat right above the battery box.

 

I'm wondering if the switches cuts power off entirely. Or is there a bypass that keeps the computers running while shutting everything else off.

 

Get a good one, we use NOCO GEN5X1 and GEN10X1 charger/maintainers on many trucks that don't have the Maxwell Starting unit. These work the best that we have found.

 

I bought the noco genius 2. But I'm not sure it works properly. After immediate hookup. The red light was flashing. Indicating 25% charge at 12.8 volts after shutdown.

I brought it home to test on my motorcycle agm. It had 13.05 volts from the HF maintainer charger being on it. THE noco flashed the red light. Red went solid at 13.1. After 4 hours it was still red at 13.1.

The manual says 14.5 volts. While can understand 14.0 volts with engine running and electrical loads. I can't see 14.5 being good on a battery not being used for nothing but computer drain. If it even gets there.

If it holds a solid red and 13 volts. I can live with that. Otherwise. I may just go with the HF unit at .75 amps. Since I know it holds at 13 volts.

The batteries are fully charged anyways when it gets parked so it don't have to do much but maintain for the extended park times beyond the typical 2 day weekend.