K7MDL
Senior Member
I have a 50Ah LiFePO4 battery and 50amp capable waterproof DC-DC converter with integrated solar charger today for my ham radio battery needs. I use them in the truck cab today, tapping off the 6GA cable run between the camper and the alternator so that the camper batteries can power my radio gear.
The charger will eventually be used to charge the camper batteries when the time comes to replace the pair of AGMs. They are not even 3 years old yet, so I am not in a hurry allowing some time to consider my approach.
I have a 2022 front dinette model Hawk, so the batteries are located aft of my rear axle and are heavy reducing my available hitch weight and rear axle capacity. With the batteries in the back today, the stock camper 10AWG wiring is relatively long and I have significant voltage drop. Upgrading the wire size for faster charging requires running that new cable through the cabinets or around the outside. Moving the battery and charger to the front under a dinette seat moves the (now reduced) weight forward and minimizes the new cable run - less length, less V-drop, faster charging, less cost, less install hassle, less change to the stock camper wiring. The camper loads do not require the upsized wiring, just the path to the battery for charging.
I have read the many Li battery and wire upgrade threads here over time and thought a bunch about how I would do this, what to do about the AC power supply, if anything, solar charging wire considerations, how to avoid changing the camper if possible, being able to return it to stock configuration easily someday and avoid needing to take off the front cabinet face to make any changes if required.
I have one more requirement - power my truck cab radio gear with minimum voltage drop for my high-power RF amplifiers. I think my idea solves this problem as well and requires no change to the camper wiring for it.
I propose locating the battery, or batteries, in standard marine battery boxes outside the camper in front of the wheel wells and the front turnbuckle eye bolts. The DC-DC charger can go in the same area. Mine is waterproof but non-waterproof versions could go into a taller box with battery and charger together, or at least stacked, something you can to with Li batteries vs lead acid type batteries. That truck bed space is normally unused and sizable.
The marker lamp wire and heavy cable from the alternator terminate at the charger, now located in the truck bed for minimum possible length. A very short cable connects the charger to the battery. The charger gets natural ventilation. The space in the camper previously used for charger and batteries are now free for storage. The weight is reduced and moved forward. The stock camper power cable (3 wires) now plugs into the battery box. It can stay stock since the camper loads have relatively low power draw. There is 1 new 10Ga wire added for the solar panel power. Inside the camper minimal and reversible wire changes involve:
1. Bypass the camper isolator.
2. Remove or bypass the existing AGM compatible solar charger and extend the solar panel positive wire through the cabinet to the front and run it outside to the DC-DC charger solar input or separate solar charger. Easy to do since it is a smaller single wire. I would run it in the existing split loom that covers the camper connecting cable.
3. Settle on the best connectors for the above considering weatherproofing. The camper's stock Attwood connector can stay the same since it does not have to carry higher charging current.
As for my radio power in the truck cab, I would run a heavy cable from the battery box into the cab. Very low voltage drop achieved. I would therefore have 1 more battery connector than a normal install, but all outside the camper. Nothing affecting the camper wiring.
The DC-DC charger will trickle charge the starting battery when solar power is available, it may also charge when on shore power also.
The 30Amp IOTA power supply/charger in my 2022 Hawk does not use the IQ plugin of old, it is inside the power supply casing from what I can see with a flashlight. Removing the power supply looks like it requires removing the front cabinet face. I want to avoid that. It will not fully charge the batteries, but it will keep things charged enough and the alternator and solar will top off the Li battery provided the supply exceeds the loads. If this becomes a problem, then the IOTA can be updated/replaced for Li charging compatibility down the road.
Keeping the batteries inside the camper may be an advantage for severe cold weather campers, but an insulated box with heated battery should work fine. Having the batteries inside the camper makes the most sense for selling a complete slide in solution, but I do not think it is the best solution. This solution being easily reversible can appeal to such some buyer's expectations.
In summary, other than running one new solar power extension wire outside the camper, this involves minimal and fully, easily, reversible changes in the camper, frees up space for storage, reduces weight, and uses the shortest length of heavy expensive wire for the best possible charge rate, ease of install, and lowest cost. Existing shore power still works, can be upgraded if needed.
What am I missing?
- Mike
The charger will eventually be used to charge the camper batteries when the time comes to replace the pair of AGMs. They are not even 3 years old yet, so I am not in a hurry allowing some time to consider my approach.
I have a 2022 front dinette model Hawk, so the batteries are located aft of my rear axle and are heavy reducing my available hitch weight and rear axle capacity. With the batteries in the back today, the stock camper 10AWG wiring is relatively long and I have significant voltage drop. Upgrading the wire size for faster charging requires running that new cable through the cabinets or around the outside. Moving the battery and charger to the front under a dinette seat moves the (now reduced) weight forward and minimizes the new cable run - less length, less V-drop, faster charging, less cost, less install hassle, less change to the stock camper wiring. The camper loads do not require the upsized wiring, just the path to the battery for charging.
I have read the many Li battery and wire upgrade threads here over time and thought a bunch about how I would do this, what to do about the AC power supply, if anything, solar charging wire considerations, how to avoid changing the camper if possible, being able to return it to stock configuration easily someday and avoid needing to take off the front cabinet face to make any changes if required.
I have one more requirement - power my truck cab radio gear with minimum voltage drop for my high-power RF amplifiers. I think my idea solves this problem as well and requires no change to the camper wiring for it.
I propose locating the battery, or batteries, in standard marine battery boxes outside the camper in front of the wheel wells and the front turnbuckle eye bolts. The DC-DC charger can go in the same area. Mine is waterproof but non-waterproof versions could go into a taller box with battery and charger together, or at least stacked, something you can to with Li batteries vs lead acid type batteries. That truck bed space is normally unused and sizable.
The marker lamp wire and heavy cable from the alternator terminate at the charger, now located in the truck bed for minimum possible length. A very short cable connects the charger to the battery. The charger gets natural ventilation. The space in the camper previously used for charger and batteries are now free for storage. The weight is reduced and moved forward. The stock camper power cable (3 wires) now plugs into the battery box. It can stay stock since the camper loads have relatively low power draw. There is 1 new 10Ga wire added for the solar panel power. Inside the camper minimal and reversible wire changes involve:
1. Bypass the camper isolator.
2. Remove or bypass the existing AGM compatible solar charger and extend the solar panel positive wire through the cabinet to the front and run it outside to the DC-DC charger solar input or separate solar charger. Easy to do since it is a smaller single wire. I would run it in the existing split loom that covers the camper connecting cable.
3. Settle on the best connectors for the above considering weatherproofing. The camper's stock Attwood connector can stay the same since it does not have to carry higher charging current.
As for my radio power in the truck cab, I would run a heavy cable from the battery box into the cab. Very low voltage drop achieved. I would therefore have 1 more battery connector than a normal install, but all outside the camper. Nothing affecting the camper wiring.
The DC-DC charger will trickle charge the starting battery when solar power is available, it may also charge when on shore power also.
The 30Amp IOTA power supply/charger in my 2022 Hawk does not use the IQ plugin of old, it is inside the power supply casing from what I can see with a flashlight. Removing the power supply looks like it requires removing the front cabinet face. I want to avoid that. It will not fully charge the batteries, but it will keep things charged enough and the alternator and solar will top off the Li battery provided the supply exceeds the loads. If this becomes a problem, then the IOTA can be updated/replaced for Li charging compatibility down the road.
Keeping the batteries inside the camper may be an advantage for severe cold weather campers, but an insulated box with heated battery should work fine. Having the batteries inside the camper makes the most sense for selling a complete slide in solution, but I do not think it is the best solution. This solution being easily reversible can appeal to such some buyer's expectations.
In summary, other than running one new solar power extension wire outside the camper, this involves minimal and fully, easily, reversible changes in the camper, frees up space for storage, reduces weight, and uses the shortest length of heavy expensive wire for the best possible charge rate, ease of install, and lowest cost. Existing shore power still works, can be upgraded if needed.
What am I missing?
- Mike
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