Maintaining batteries

[Silas_Carpy]

New to rving as of May this year so first time winterizing. If I understood everything I read, including owners manual, I can leave batteries in rv and connect to shore cord and inverter will maintain charge. I’ve had it hooked for about 3-4 weeks now. I’ve been monitoring the batteries and today the 12 volt chassis battery was at 11.55 volts and the 6 volt coach batteries were 5.85. Does this method not maintain charge. 2009 Fleetwood pulse on dodge/Mercedes’ sprinter. Thanks.

[Boon_Docker]

wa8yxm:
I always thought that my pair of GC2 batteries were in fact 6 volt batteries. :B

[wa8yxm]

Silas Carpy wrote:
Thank you all for advice, I have volt meter, it is what I’m checking with. I’ve decided to get charger/ maintainers for 12v and 6v, any recommendations on best? Also, my 2, 6v house batteries are connected together, is this considered series? Would charger connected to one maintain both? Lastly, I’ve seen 2 bank chargers. Does anyone know if these can be set to 2 different voltages, one 6 and one 12? Thank you again.

One thing you need to re-think. Though I know you have "Six volt batteries" you look at 'em. they have 3 caps each. say 6 Volt on them.

The fact is there are no 6 Volt batteries in RV's. Now here is why I say that

They are wired like this

-{6V}+-{6v}+ = 12 volt

They are wired so as to be a 12 volt battery Just split in two parts for assorted reasons. One of which is easy of installation.

A 4D (250 AH DEKA) is just shy of 100 pounds
A GC-2 is about 70 220 AH. (Close enough to compare)

A 220 ah unit I could life into/out of my RV. but a 230 AH unit I needed help.

[pianotuna]

Silas Carpy wrote:
I guess I haven’t been around long enough, bob’s my uncle???

It means problem solved.

[Silas_Carpy]

I guess I haven’t been around long enough, bob’s my uncle???

[pianotuna]

Silas Carpy,

Don't fix what is not broken.

Here is what I would do in your shoes.

1. make sure there is power coming from the converter (or inverter charger) to the battery bank.

Do this by measuring the voltage at the bank, then plug in, wait a couple of minutes, and measure voltage again. If it has gone up--then bob's your uncle.

2. for the chassis battery add a trick-l-start. I've been using one for 8 years. No jumping needed even at temperatures in the -30 range.

3. Consider adding a modest solar charging system to the RV. Your battery bank will love you for it.

[CA_Traveler]

The house should be 13.4V, which is the float voltage of a fully charged battery connected to a charger. Exactly what is the voltage? And the exact chassis battery voltage.

There is no need for a 2 bank tender long term and may not be a long term solution.

Did you check initially to see if you had 120V in the MH?

[Silas_Carpy]

Thanks, I’m more confused than ever now. Tested them today and got over 12v and6v, respectively. Also, my aux battery light is on and won’t turn off even though plugged in to ac. I’m just gonna get a two bank tender and plug it directly into my extension cord, leave shore power off. Thanks again.

[CA_Traveler]

Consider carrying a 10A+ battery charger as you travel just in case.

Also have the batteries load tested or buy a tested and do it yourself. Your battery life/capacity is already compromised and may need to be replaced.

[CA_Traveler]

Measure across the outer 2 6V battery posts and if they are 11V+ they are connected correctly. ie You have a 12V battery. Get it charged with say a auto battery charger. You need to find out why they are not being charged by your house charger. Note the charger may/may not charge the engine battery depending upon how it was set up or modified.

Also start the engine, first charging the chassis battery if needed. The alternator should charge both batteries raising the voltage on each to 13-14V, just like a car. This is a test as it can take several hours of driving to fully charge discharged batteries.

Until BOTH battery banks are being charged/maintained correctly you will likely not be a happy camper.

[Matt_Colie]

Silas Carpy wrote:
Thank you all for advice, I have volt meter, it is what I’m checking with. I’ve decided to get charger/ maintainers for 12v and 6v, any recommendations on best?

Also, my 2, 6v house batteries are connected together, is this considered series? Would charger connected to one maintain both? Lastly, I’ve seen 2 bank chargers. Does anyone know if these can be set to 2 different voltages, one 6 and one 12? Thank you again.

Silas,

The 2ea 6volts make one 12V and keep thinking about it that way.

As was said, get a charger on both banks as soon as possible.

Find the date/year marks on all the batteries, and if they are over 5 years old, be suspicious. You bought the coach used, so you have no history on those batteries and there is every possibility that they are over age or have been depleted too many times.

It is very easy to correct all this, and not seriously expensive if you buy things right.

Matt

[Silas_Carpy]

Thank you all for advice, I have volt meter, it is what I’m checking with. I’ve decided to get charger/ maintainers for 12v and 6v, any recommendations on best? Also, my 2, 6v house batteries are connected together, is this considered series? Would charger connected to one maintain both? Lastly, I’ve seen 2 bank chargers. Does anyone know if these can be set to 2 different voltages, one 6 and one 12? Thank you again.

[pianotuna]

Silas Carpy,

Welcome to the forums.

It is good you noticed there is an issue with charging.

My RV requires the battery disconnect switch to be "on" for the converter, or the inverter/charger to do battery maintenance. If it is "off" no charging happens.

Many RV's do not charge the "chassis" battery. One of the popular ways to make this happen is to add a Trik-L-Start.

It is prudent to carry a volt meter (an elcheapo from Harbor Freight would be good enough)

If the battery switch is on, then check the output at the converter, or inverter charger.

Converters usual have reverse polarity fuses. They sometimes fail.

Others have given you excellent advice in the thread.

Do let us know what the solution to the problem is.

[Skibane]

Silas Carpy wrote:
I’ve been monitoring the batteries and today the 12 volt chassis battery was at 11.55 volts and the 6 volt coach batteries were 5.85.

11.55 volts is almost completely dead.

Your battery maintainer isn't working.

A maintainer that actually works will keep the batteries at around 13.5 volts (which would be 6.75 volts on each 6 volt battery).

Note that most house battery chargers only maintain your house batteries - not your chassis batteries.

In order to also maintain your chassis batteries, you'll probably need to add a diversion charger (which "steals" a little bit of current from your house batteries to also keep the chassis batteries charged).

A couple examples of diversion chargers:

Xantrex Echo-Charge

LSL Products AMP-L-START

[Vintage465]

I didn't notice any mention of the battery's age. That being said, they may not take a charge due to age or mis-use. Beyond that it's a matter of making sure there 120v into the converter and 12v-14.4 volts out of the converter. I'm not much of a fan of maintaining batteries with a converter, but there are decent ones out there like Progressive Dynamics. I have a WFCO and have little good to say about it. I mean, it works but I'd never trust it to care for my $600.00 worth of 6v golf cart batteries.