Community Forums

robebur · 10-21-2021, 04:28 AM

My Challenger MQ35 is powered by 2 6v house batteiries. Seems light to me. Is it easy to hook up more 6v batteries in a parallel series? I am plugged in most of the time and have a solar charger. Adding the batteries in parallel series seems easy, knowing which leads to hook up to is a bit confusing. Also, what things should I look for in the new batteries to make sure they are compatible.

Mark_K5LXP · 10-21-2021, 04:50 AM

If you're on shore power most of the time then it seems you'd be buying a bunch of battery capacity that will go unused. But, adding a pair is indeed straightforward. Diagram below shows the typical layout.

Some will jump in and say that all the batteries should be the same manufacturer, type and age. This is true, for "optimum" performance. There's a gray area in there where if you don't cycle your batteries often and deeply you will likely have good service from a mismatched pack. Replacing the ones you have checks the box but unless you need "optimum" you can consider running the clock out on them, then replace them as a set next time around.

Mark B.
Albuquerque, NM

Gary RVRoamer · 10-21-2021, 12:26 PM

Agree with Mark - why buy more batteries if you are mostly on shore power? Just a waste of $$ and space.

A pair of 6v GC2 (golf car) batteries typically provide 210-230 Amp-Hours of capacity. That's a reasonable amount as long as you don't need to operate off-grid very often or for extended periods.

SKP Kirk · 10-21-2021, 04:49 PM

Quote:

If you're on shore power most of the time then it seems you'd be buying a bunch of battery capacity that will go unused. But, adding a pair is indeed straightforward.

Absolutely correct. It would be a needless waste of money and a waste of space and weight capacity.

robebur · 10-22-2021, 04:09 AM

So those batteries should run my fridge while going down the road? I have a solar charger and a 1800 watt inverter. I assume the batteries will charge while the engine is running as well.

EdInArk · 10-22-2021, 04:21 AM

I agree with everyone. How'd that happen?

Yes, your batteries should charge while you're rolling down the road. We leave our fridge running most of the time and installed a 30-amp plug at home.

sbleiweiss · 10-22-2021, 07:56 AM

Quote:

Originally Posted by robebur

So those batteries should run my fridge while going down the road? I have a solar charger and a 1800 watt inverter. I assume the batteries will charge while the engine is running as well.

We never dry camp, but get along fine with two 6 volt golf cart batteries and no solar. Residential fridge is no problem driving and no problem for short gas or rest stops.

Gary RVRoamer · 10-22-2021, 08:16 AM

Quote:

Originally Posted by robebur

So those batteries should run my fridge while going down the road? I have a solar charger and a 1800 watt inverter. I assume the batteries will charge while the engine is running as well.

Yes, though we can't guess how long without knowing more about the fridge. Certainly plenty for several hours, though, and more likely 10-16 hrs. And since the engine alternator charges batteries, the batteries don't even get discharged while driving.

Grapehound · 10-23-2021, 01:42 AM

I hope the OP had his questions answered and I am OK to ask a related battery question. I don't have a good understanding of RV batteries.

I have a 2010 Winnebago Tour and my coach battery bank is showing 10.5 volts after being stored in disconnect mode for a week or so. The chassis batteries are in the 12.5 range after storage.

We always camp with full hookups and never boondock. The coach starts and runs fine. The coach batteries show 12.5 after charging for a while, either driving or on shore power. It's just that they drop to 10.5 volts after storage.

Should I be looking at replacing the coach batteries?

Mark_K5LXP · 10-24-2021, 07:58 AM

10.5v static voltage implies a bad cell or persistent load. So while a 'bad' battery would explain it, so would a load that's still on the battereries despite the 'disconnect'. The test I would do is charge the batteries then physically disconnect the bank by lifting one of the cables. One can measure if ther's any amount of discharge current at that point with a basic multimeter. From there you can watch the battery voltage to see if it diminishes or holds steady. If it's a flooded battery using a hydrometer to measure the electrolyte can reveal a bad cell. Provided everything seems to be checking out to this point a capacity test will conclusively prove battery merit and show wheter the issue is the batteries or the house load.

Mark B.
Albuquerque, NM

wolfe10 · 10-24-2021, 08:05 AM

Quote:

Originally Posted by Grapehound

I have a 2010 Winnebago Tour and my coach battery bank is showing 10.5 volts after being stored in disconnect mode for a week or so. The chassis batteries are in the 12.5 range after storage.

Should I be looking at replacing the coach batteries?

Best answer is to fully charge them and then have them load tested. Free at most places that sell batteries.

You can also fully charge them and use a BATTERY HYDROMETER (under $10 at any auto parts house) to check them.

This will give you the FACTS to make a reasonable decision. Better than our speculation.

BTW, while on shore power (i.e. converter or inverter/charger charging them) you should be in the 13.2-14 VDC range. Same while driving and the alternator charging them.

Cat320 · 10-25-2021, 04:08 PM

Quote:

Originally Posted by Gary RVRoamer

Agree with Mark - why buy more batteries if you are mostly on shore power? Just a waste of $$ and space.

A pair of 6v GC2 (golf car) batteries typically provide 210-230 Amp-Hours of capacity. That's a reasonable amount as long as you don't need to operate off-grid very often or for extended periods.

Exactly! Two months ago changed eight 6v deep cycle AGMs for two 12v deep cycle AGMs. Working fine.