Deep Cycle 6V Chargers - What Do You Use?

[Socco1]

Evening All,

I just got back from a 5 night trip. No hook ups and no generator... So needless to say that my two T-105 Plus batteries took a pounding. This is the first time that I've dealt with charging 6V Deep Cycles, as I put them in mid-season and never used them more that two days at a time.

My trusty little Schumacher SP-3 won't cut it, so I dragged out the old wheeled charger to get them charged up.

What do you use for a charger? I fear using the big one I have (50A at 6V) will damage the batteries, as I can only twist the timer on and hope for the best. I've been spoiled/dumbed-down with these new digital chargers.

[BCx213]

I charged my 2-6 volt batteries by keeping them connected as 12 volts but disconnected the leads to the trailer. I put them on my 12 volt smart charger and they took the charge fine, just took longer.

[edatlanta]

Since you have them connected in Series just charge them together as one 12 volt battery. Higher amperage will just charge them faster, but the newer smart chargers will turn off or slow to a trickle before they are damaged. My converter charges mine fine.

[3'senough]

Originally Posted by edatlanta

Since you have them connected in Series just charge them together as one 12 volt battery. Higher amperage will just charge them faster, but the newer smart chargers will turn off or slow to a trickle before they are damaged. My converter charges mine fine.

I have done the same on mine for the last 6 years with both my current and previuos unit. The converter charger has maintained them well. If you are going to leave it in for week the smart charger should get them back up to 99% over the course of that time.

If you have a high amp charger then that would be your fastest way to recover them in a short period of time.

The 6V take a beating better due to the plate size and being a true deep cycle so you should be good to go.

[Mustang65]

From a batteries point of view, your best bet is to charge them in series as a 12VDC system, with a smart charger that is designed for "Deep Cycle" batteries (3 modes). The reason for this is that when you charge them as a 12VDC setup, they will be charged equally. It sounds like you will be charging them upon your return from each weekend of dry-camping and getting them charged for your next outing. There is no need for a high voltage FAST charge, deep cycle batteries do not like FAST charging, and it will have an affect on how long they last.

A 10amp, 3 mode smart charger will do fine and bring them back to a full charge in a few days.

What concerns me is that you may be draining the batteries while dry camping to a voltage that is less than 12VDC (50% rule). 12 volts is considered a DEAD battery, 12.6 volts is considered a "Fully Charged" battery. If your batteries are being drained to a point less than 12VDC, you need to address that issue, as that will also shorten the life of your batteries ($$$). Purchase a 12VDC digital display meter off Amazon, hook it up inside your TT and monitor your usage while camping. This will allow you to shut down your batteries once they hit the 12VDC level.

As a last ditch effort, you may want to charge them for a while each morning and night with the TV while dry camping, using jumper cables. It will not bring them back to a 100% but it will put a little life back into them.

Good Luck,

Don

[edatlanta]

I know everyone her has an opinion on what stage of discharge is damaging to batteries so I wrote to Trojan concerning their T-105's. I have two of them in my 5'er that I bought in 2010 (still going strong after 5 years use) and I use the same battery in a golf cart. My question to Trojan was what is considered the lowest charge level they recommend without sustaining damage to the life of their T-105. Here is their response:

Below is Trojan Battery's response:
We never want you to discharge your batteries below a 20% state of charge (80% depth of discharge). For a 36 volt system of batteries this would mean you never want to go below about 35 volts. The voltage of 34.9 volts is an open circuit voltage, which means the batteries would be at rest. For your 12 volt RV system, a 20% state of charge would be an open circuit voltage of 11.6 volts. Thanks.
If you have additional comments or questions, please contact me at the information below.
Sincerely,
Stacey Delzeit
Product Engineer
Trojan Battery Company
sdelzeit@trojanbattery.com
678-518-7378

[Mustang65]

Here are Trojan's numbers for the life of their batteries. Compare 50% vs 80%.



Don

[Socco1]

Thanks for the input everyone. Allow me to clarify a little...

I did keep an eye on the batteries while we were camping with a DVM. I did not see lower than 12.2V, IIRC. I hooked the TV up with jumper cables for an hour on our last night. This was because it snowed and I did not want to risk the wrath of a cold spouse!

When the trip was over, I pulled the batteries off the TT and brought them home to charge. Since they were fairly low, my SP-3 would see this as a fault and stop charging. I used the trusty 'ol 225 Amp wheeled charger (Set at 6v 40A) to bulk charge prior to switching over to the SP-3. I didn't think to charge them as 12v at the time.

I'm wondering what charger people are using for deep cycle batteries at home and "on the bench," not in the RV. I don't want to damage the batteries by charging them too quickly, T-105s aren't cheap!

[NC Roamer]

Originally Posted by Mustang65

Purchase a 12VDC digital display meter off Amazon, hook it up inside your TT and monitor your usage while camping. This will allow you to shut down your batteries once they hit the 12VDC level.

I can use the inverter display in the Greyhawk to check the house battery voltage, right?

[Bassdogs]

2 6V batteries connect in series are basically one 12V battery and can and should be charged the same as you would any other 12V battery. Forget the 6V charger, you now have a 12V system.