26 replies to this topic

[Jon R]

Paul T:

 

Are you saying you have two GC2 batteries installed with the terminals facing up?  It seems like that would just barely fit lengthwise  based on measurements and specs, and your confirmation that it actually fits that way gives me another option.  Thanks.

[PaulT]

Yes.

Paul

[Jon R]

Thanks for posting the picture. My question wasn’t precise enough. I was thinking you installed them blue side up. The compartment is 22” long and the battery long dimension is 11”, so I was thinking they might barely fit that way. Update: after looking at the door opening size and position relative to the side walls of the compartment, I realized that, while two gc2 batteries could barely fit the compartment blue side up, you wouldn’t be able to get the second battery through the door.

Edited by Jon R, 31 December 2020 - 04:44 AM.

[BrianG]

Paul, where have you located your solar controller and DC/DC charger if you have one? Great thread on ways to get two 100ah BB’s in a Hawk. 

[PaulT]

In the photo above:

Top left with two LED glowing on left side is the Bogart SC-2030 PWM charge controller programmed for LiFePO4 batteries.

 

Immediately to its right is the shunt for the RV-2030 battery monitor mounted on surface of the cabinet to the left of the cabinet door but not seen.. 

 

To the right of shunt is the tie point for the ground wires. Below that is a tie point for the solar panel ground wires to the SC-2030.

 

Continuing to the right is a 50 amp circuit breaker enabling me to disconnect the solar panels when working on the electrical.

 

Above the circuit breaker is the original Battery Isolator still mounted but disconnected from the truck alternator. Above the Isolator is the IOTA DLS-30 charger/power supply. The IQ4 module is screwed to the ceiling of the battery compartment.

 

Attached to the battery lug between the batteries is an MRBF Terminal Fuse Block  I like them because you cannot get any closer to the terminal with any other fuse and it puts the wire lugs up top and the wires flat compared to others. 

 

Things could be much neater and straighter if I were left handed or young and flexible so I could more easily operate tools in that tight space. I pulled the two factory AGM group 24 batteries and the GC2's fit right in after I removed the 1/2" square wooden space holder in the forward bottom of the compartment at the foot of the rightmost battery.  Because the GC2 batteries are taller than the AGMs, the left most GC2 was getting a little close to some wires and bolts in the top left side of the compartment.

 

They are shoe-horned in there but they fit and weigh half as much as the AGM batteries they replaced.

 

Paul

 

[BrianG]

Thanks Paul, stacking batteries opened up some interesting options for multiple lithium batteries. 

[PaulT]

The Battleborn  GC2 LiFePO4 batteries are installed right side up.

 

https://battlebornba...-cycle-battery/

Although Battleborn’s web pages on the GC2 can be misread, the GC2 width and length fit the GC2 spec, they are 12v batteries and not 6v like lead acid Golf Cart 2 batteries.
Paul

[Jon R]

Thanks Paul, stacking batteries opened up some interesting options for multiple lithium batteries.

After measuring it appears one could fit two Battleborn 100 Ah (non gc2) batteries either stacked on their sides or resting on end, in both cases with the terminals facing the door.

[Jon R]

FYI for everyone:

 

I traded emails with a Battleborn support person yesterday and he said that there is no problem with stacking two of the 100Ah batteries laying on their sides from either a battery case structure standpoint or a thermal standpoint.  (I made clear my question was about use in a truck camper that would go off road.)  He also said that if you start with one battery initially, you can add another new battery of the same model up to two years later without having any balancing issues. 

Edited by Jon R, 21 January 2021 - 02:32 AM.

[BrianG]

JonR,

 

Have you considered placing them under the dinette drivers side seat. Isn’t that box in the Grandby longer than in the Hawk. The batteries only sit about 10”s high. You could build a platform above them for some usable space. Everything would be easy to get at and you would have space in the original battery case for storage.