15 replies to this topic

[ski3pin]

A lot of options for battery systems in pop up camper have been well covered on this forum. Here's what I did in our ATC Bobcat. We have a smaller camper so it takes creativity to keep systems compact and light. A year ago I replaced our AGM battery with a Renogy lithium 100ah smart battery. I installed a Renogy 50A dual charge controller to maintain the battery. I build the camper in a side dinette style. The seats are also lids to storage underneath. The front seat has an angled seat back against the rear wall. I installed the dual charge controller behind the seat back.

 

 

 

 

 

 

 

My main camper power switch is on the left. The fuse box is auxiliary and for the two power points to the right (will be visible in a photo below). The main wires run below to the battery.

 

 

 

 

 

 

I installed new 6awg from the truck's engine bay to the camper and used 6awg for the short lengths between the controller and camper battery.

 

 

 

 

 

 

Below is the seat back in place along with the protection for the battery. In regard to heat generated by the controller. I have vent holes in the sides of the seat back support, the hole in the bottom front to view the indicator lights, and the top of the seat back support is open. In a year of use, I've not felt any heat from the unit.

 

 

 

 

 

 

Below is the hinged padded seat in place.

 

 

 

 

 

 

I works well for us and is compact.

[ckent323]

ski3pin,

 

Does the Renogy controller provide two different output charging voltages with each adjustable (programmable) for different battery chemistries?

 

Edited by ckent323, 29 October 2022 - 11:18 PM.

[ski3pin]

Insofar as charging the camper battery, there are settings for the various types of battery (lead acid, AGM, lithium) along with the ability to customize a charging profile. Can this be done for charging the lead acid truck battery - after the camper lithium is fully charged? I have never looked. I use the lithium battery profile in the charge controller since I'm using a Renogy battery.

 

Here is a link to the manual - Renogy Dual Input

 

Did I hit what your question was?

[TacomaAustin]

@Craig

 

I recently installed the smaller 30 amp dual input Renogy charger - with the hope that it will never stress my 130 amp alternator.  My ATC Bobcat is mounted on a 17 year old Toyota Tundra.  I want the amperage draw to be limited.

 

Charging parameters: The first mention that Renogy gives with regards to the charging parameters of the lead acid starter battery is on page 6 - "Trickle charges the starting battery via solar panels if the service battery is fully charged."  The service battery is the camper's house battery.

 

Over on page 13 - "If the service," a.k.a house "battery is in the float charge state, the starting battery will be charged at the same time.  The charging voltage is limited to 13.8V. "  On a lithium install there is no float cycle.

 

One thing to note, the charging of the vehicle's starting battery appears to be an intermittent on / off affair. 

 

According to Renogy - "After charging the starting battery for 1 minute, it will disconnect for 30 seconds and check the starting vehicle voltage.  - It will continue to charge the starting battery, if the voltage is lower than 12.7V and will stop charging if the voltage is higher than 13.2V."

 

So in my words, the charging voltage supplied to the truck's starting battery is 13.8V. 

Edited by TacomaAustin, 30 October 2022 - 12:18 AM.

[TacomaAustin]

I installed a Renogy 50A dual charge controller to maintain the battery.

 

I works well for us and is compact.

 

A question for ski3pin - at the other end of the #6 gauge wire inside the engine bay, did you use a fuse or a breaker similar to what is mounted above your camper battery?

 

 

 

 

 

[ckent323]

Tacoma Austin, ski3pin, et al,

 

If the following is true then it seems to me it should be OK - It will continue to charge the starting battery, if the voltage is lower than 12.7V and will stop charging if the voltage is higher than 13.2V."

In this regard it apparently works similar to an ACR.

If it charges the AGM starting battery to 13.8 V and stays connected that may result in overcharging the AGM (depending on the manufacturer) and harm it.   I think an AGM float voltage of 13.2 V to 13.5 V is safer (~2.25 V per cell) - but that is for my 6 V deep cycle AGMs.  A 12 v starting AGM may tolerate up to 13.8 V.

 

There is some variation of the best charge voltage with temperature as well, increasing a couple of 1/10s of a V per cell for every 5 C drop in temp below 25 C and decreasing a couple of 1/10s of a V for every 5 C temp increase above 25 C.

Edited by ckent323, 30 October 2022 - 01:03 AM.

[ski3pin]

 

A question for ski3pin - at the other end of the #6 gauge wire inside the engine bay, did you use a fuse or a breaker similar to what is mounted above your camper battery?

 

 

 

 

 

 

Yes, the same as the breaker at the camper battery. I believe I used the Will Prowse (?) video "how to" directions on the install.

 

Thanks to you both for the expertise on the charging of the truck battery. My approach has been much more seat of the pants. The truck battery hasn't shown any issues. There's been no sign of off gassing - wet battery top - and the starter immediately turns over.

[billharr]

Great use of space putting the controller in the seat back. Lithium is a game changer.

[TacomaAustin]

Yes - 3pin did a nice out of the way install that is compact and unobtrusive.

 

I built my panel as a 1 piece board outside of the camper and installed it about a month later.  It ended up taking up more space, mainly to my preference for separate bus bars and placement of two resettable breaker within inches of the Renogy 30 amp dual input controller for short wire runs.

 

Here is the circuit panel before the install - note the lack of a 40 amp fuse between the controller's positive post and my positive busbar, which has since been resovled.

 

 

Attached Files

•  RenogyBoard.jpg   167.99K   42 downloads

[TacomaAustin]

I also want mention that this particular Renogy controller draws 63 milliamps - while in standby.  Therefore, it is handy to have a device to isolate the house battery from the controller for when the camper is indoor storage.   .063 amps = about a 1.5 amp hours of parasitic loss per day.  Over a 30 day period the parasitic loss will add up to a 45 amp hour drain.