So, I just bought a new 5th wheel toyhauler. It currently has a single 12v battery. I want to seriously upgrade the battery capacity.
I had 2 Costco 6v golf cart batteries in my last rig. I think I want to go to 4 batteries in the new RV. I'm interested in the Trojan T-1275 (12v 150AH at 20hr). I can get them for $158 each plus core locally.
I have space for 2 batteries on each side of the RV. This means I would have to run cable between the sides, which looks like it will be fairly easy.
Some more variables. I currently have 150 watts of solar with a Zamp charger. Looking to upgrade to ~450 watts. I also have a 2k watt pure sine wave inverter.
Here is how I *think* it should be wired.
This would require 3 wires (1 power and 2 ground) to the other side of the RV. I'm thinking some like 1/0 or 2/0 for these runs.
So, my questions are these. Is it ok to have the battery banks spread apart like this? Is 1/0 big enough?
I had 2 Costco 6v golf cart batteries in my last rig. I think I want to go to 4 batteries in the new RV. I'm interested in the Trojan T-1275 (12v 150AH at 20hr). I can get them for $158 each plus core locally.
I have space for 2 batteries on each side of the RV. This means I would have to run cable between the sides, which looks like it will be fairly easy.
Some more variables. I currently have 150 watts of solar with a Zamp charger. Looking to upgrade to ~450 watts. I also have a 2k watt pure sine wave inverter.
Here is how I *think* it should be wired.
This would require 3 wires (1 power and 2 ground) to the other side of the RV. I'm thinking some like 1/0 or 2/0 for these runs.
So, my questions are these. Is it ok to have the battery banks spread apart like this? Is 1/0 big enough?
Well, the 1275s didn't fit....... Off by about 1/4 inch on the length (Thank goodness I wasn't cutting anything). I missed an inside bracket when I measured. I was worried about height, but that was more than sufficient. I'm going to take them back and likely go T-125 in a series/parallel arraignment.
I ordered a Trimetric earlier this morning. I think it's going to be very insightful when it comes to understanding our actual usage. The new rig has a lot more toys so I look forward to seeing what the cost of using these are to my energy profile.
So, if I understand correctly I can run the series on each side (2 x t-125). Ground each of these separate banks to the chassis. Run a positive between them and a separate negative to the trimetric shunt.
Is this correct?
I ordered a Trimetric earlier this morning. I think it's going to be very insightful when it comes to understanding our actual usage. The new rig has a lot more toys so I look forward to seeing what the cost of using these are to my energy profile.
So, if I understand correctly I can run the series on each side (2 x t-125). Ground each of these separate banks to the chassis. Run a positive between them and a separate negative to the trimetric shunt.
Is this correct?
DrewE wrote:
I'm not sure why you'd need the ground to go to the other side; just find a good ground on the ground side of the RV. Maybe I'm missing something (perhaps needing a lower impedance ground than the chassis provides for the inverter).
What you post at the top is not quite balanced, as it turns out, but only pretty close. See http://www.smartgauge.co.uk/batt_con.html for a more thorough explanation, and (at the end) this nifty approach:
If you draw a horizontal line separating the four batteries shown you will see the positive needs to be connected on one set and the ground on the other set. If he uses existing conditions both + & - will be on same side.
I'm not sure why you'd need the ground to go to the other side; just find a good ground on the ground side of the RV. Maybe I'm missing something (perhaps needing a lower impedance ground than the chassis provides for the inverter).
What you post at the top is not quite balanced, as it turns out, but only pretty close. See http://www.smartgauge.co.uk/batt_con.html for a more thorough explanation, and (at the end) this nifty approach:
What you post at the top is not quite balanced, as it turns out, but only pretty close. See http://www.smartgauge.co.uk/batt_con.html for a more thorough explanation, and (at the end) this nifty approach:
Yes you can do that all sorts of ways.
-If you run parallel links to join each "pair" you only need to ground one to the frame.
-You can have one side only do the inverter and give it its own solar set for recharging plus a portable charger when no solar. the other side can do the usual rig stuff, and have its own solar set and charger. Now you don't need the long parallel links
-You can put the inverter in the middle and have two wire sets for it.
Two wires from pos terminal and two from its neg terminal. One pos and one neg to each "pair". Now the inverter-battery wires are also the parallel links and they don't have to be so fat since each is carrying about half the amps.
-If you have a Trimetric with its shunt, it means if you split the bank you can only monitor the pair the shunt is on, but you don't really need a momnitor anyway ๐
I have played with these set-ups a different times and they all work.
You need to recharge those T-1275s seriously to 14.8v temp adjusted or they won't last, so don't expect to keep them going with a 14.4 volt converter. A solar controller with adjustable voltage will help with that, plus an adjustable voltage charger for when not using solar. This type would be a good choice for that--he can do one up as a 100 amper for you.
http://www.bestconverter.com/Boondocker-BPCM-75-75-Amp-Adjustable-Power-ConverterCharger_p_587.html#...
Here is one of my past set-ups with the two T-1275s on inverter only with the Solar30 controller and the four 6s (two are out of sight to the right) doing the rest of the work with an Eco-Worthy controller for them. The Trimetric would only do the four 6s in that set-up.
-If you run parallel links to join each "pair" you only need to ground one to the frame.
-You can have one side only do the inverter and give it its own solar set for recharging plus a portable charger when no solar. the other side can do the usual rig stuff, and have its own solar set and charger. Now you don't need the long parallel links
-You can put the inverter in the middle and have two wire sets for it.
Two wires from pos terminal and two from its neg terminal. One pos and one neg to each "pair". Now the inverter-battery wires are also the parallel links and they don't have to be so fat since each is carrying about half the amps.
-If you have a Trimetric with its shunt, it means if you split the bank you can only monitor the pair the shunt is on, but you don't really need a momnitor anyway ๐
I have played with these set-ups a different times and they all work.
You need to recharge those T-1275s seriously to 14.8v temp adjusted or they won't last, so don't expect to keep them going with a 14.4 volt converter. A solar controller with adjustable voltage will help with that, plus an adjustable voltage charger for when not using solar. This type would be a good choice for that--he can do one up as a 100 amper for you.
http://www.bestconverter.com/Boondocker-BPCM-75-75-Amp-Adjustable-Power-ConverterCharger_p_587.html#...
Here is one of my past set-ups with the two T-1275s on inverter only with the Solar30 controller and the four 6s (two are out of sight to the right) doing the rest of the work with an Eco-Worthy controller for them. The Trimetric would only do the four 6s in that set-up.
