My battery, water level and charger - it's surprising what I don't know

[camaraderie]

ependydad...worst case get a 10 buck digital meter at home depot or amazon and at least you can read the volts correctly...since 10th of a volt matter..you really need digital. Best case...spend the $60 bucks at amazon for the AC/DC clamp meter and you can actually see what is going on with your electrical use in the camper.
Caution...get this one below if you want the AC/DC amp readings. MANY cheaper ones say AC/DC clamp meter but ONLY give AC amp readings. There are a few others on Amazon that with do the AC/DC amps...but check back before buying any of those to confirm they will do what you want.
Once you get the new battery on a charger...take a volt reading while it is charging...you should get a reading between 13.2 and 14.5 volts. This will confirm your charger is working properly. Then take it off the charger and take a reading... after waiting 24 hours. That will be the real state of charge of the battery. 12.6 or 12.7V is full.
Here's the Amazon meter GLJ was talking about:
http://www.amazon.com/Auto-ranging-D.../dp/B001VGND88

[ependydad]

Thanks, camaraderie- I've just ordered this one from Amazon:
http://www.amazon.com/gp/aw/d/B000X5...A39WJT90MMXLA5

I wasn't ready to spring for $60 at this point though the clamp on ones look useful.

[camaraderie]

Yer welcome...understood. You've got what ya need for the basics and you can even do penetrative DC amp measurement with it if you really need to. Have fun!

[ependydad]

I feel like this is the never ending "hey, imma idiot@ thread.

[camaraderie]

^^^Dressed as you are in your avatar..is that not a forgone conclusion?^^^

[ependydad]

Originally Posted by camaraderie

^^^Dressed as you are in your avatar..is that not a forgone conclusion?^^^

Hey, I'm a triceratops!

[ependydad]

Ok, I received my $15 digital multimeter today (the craftsman that I linked to above). The battery was showing a resting charge of 12.48:


Per the Trojan Users Guide, this appears to be about 80% charged:


I then plugged it into my cheap charger:


It measured 14.8 but slowly increased up beyond 15 (every 4-5 seconds it increased by 1/100th; yes, I stood there for a while!):


I don't really know what that means.

Per the users guide, I seem to be looking for a charge of 14.8 (at least?):

[camaraderie]

Well...yer off to a flying start! Good.
Basically... when the battery is discharged below 80%...you want a charger that will go into bulk charging mode at about 14.8V.
Then..after it is charged a while...no more than a couple of hours etc. the voltage should ramp down into the low 14V range IDEALLY.
Then, once the battery is nearly fully charged...the voltage should drop to about 13.2 volts and hold there till you remove the leads.

The above is ideal. It IS not good for any battery to charge over 15% except on a controlled EQ cycle....which you were not attempting. So...you are using what looks to be a fairly cheap 10amp charger..can't see the brand model from the pix... and it is not well controlled if you are getting over 15V. What I would do is open the pods so the water/vents are exposed and insure that water levels are fine...and have some distilled water on hand as 15 volts will boil it off if it stays at that level.
I suspect you will find that the voltage falls into the mid-14V level within 15-20 minutes...which is FINE for bulk charging even though 14.8 is your ideal.
If it stays at over 15V for more than an hour...or if it EVER gets to 15.5...stop the charging process and get a new charger.

Assuming it drops back into the mid 14V level...you should next see a slow decline into the 13.2-13.6 V range after a few hours. If you're not there by 8 hours...turn off the charger refill any water needed and close it all down. Check the resting voltage 24 hours later and you should see 12.6 or 12.7 V

Finally...a little over 15V for a little while is NOT a problem. It is only a problem if you continue to see that an hour later!
Can you provide make/model number of your charger so I can see what it CLAIMS to do?
Best...

[Witch Doctor]

Doug, good advice from Cam, I think your going to be okay, Sure wasn't any 7 volts the analog was reading. I think your well on your way. Being an IT guy do you have an excel program for a trip log that you developed?

[RPAspey]

X2 what Camaraderie said. The voltage from the charger must be higher than battery voltage in order to "push" current into the battery. But as it was mentioned, too high for too long will "boil" off fluid and damage the battery. Oh, the best way to measure the state of charge is to get yourself a good hydrometer to measure the specific. But you are getting good advice on how to check it with a meter. Besides, looks like you needed a meter anyway

[ependydad]

So unfortunately, I set it up to charge and then went to bed after the measurements that I took above. So I wasn't able to see the ramp down. I did check the water level before I charged it and they were fine. Per your recommendation, I also checked water levels this morning after taking it off of the charger and they appear unchanged.

I checked on the battery again this morning and the charger has switched to "charger/maintaining" mode:


Measuring the battery with and without the charger show 12.79:


From the Trojan users guide, this appears to be a 100% charge.


I'll test the battery this evening and tomorrow to see that it is staying at 12.79 or thereabouts.

And finally, the charger is an cheap charger from
Walmart. It's a Schumacher XC10. Price online shows $30, but I don't believe that I spent that much. Maybe I did.


Now, if my multimeter would just consistently work. Either my 9v batteries are crap or its finicky. I even busted out the manual for it this morning to make sure I wasn't doing something wrong. It doesn't always "clear" itself when I turn it on and switch to VDC 20. I'm going to pickup some new batteries from the store and am keeping the meter itself inside where it's warmer than the garage.

Glenn, you're right that I'm sure glad it wasn't 7v! This makes all of the difference between holy pile of crap and hey, this might actually work.

RPAspey, I actually think I'm not against the idea of a hydrometer now. I've got a lot more confidence in understanding this stuff over the last few posts/exercises. The Trojan users guide also strongly recommends one for measuring state of charge. If you're willing to find an Amazon product (that's eligible for prime shipping), I'd be interested to see what you recommend.

[ependydad]

Originally Posted by gljurczyk

I think your well on your way. Being an IT guy do you have an excel program for a trip log that you developed?

I have a couple of different Excel sheets that I use. I have one per year that I keep a log of the trips that we've taken. I keep things like:

• the start and end date
• where we went
• what site we were on
• who in my immediate family went
• what guests we had, if any
• notes about the campground
• notes about the site
• where the camper was stored before/after the trip
• mileage to the campground
• mileage from the campground
• total campground fees, if any
• if the campground was a Thousand Trails park or not

I then calculate a few things from it automatically:

• the # of nights planned (past and future)
• the # of nights we actually camped (past only)
• the number of miles that the camper has been towed
• the total campground costs that we've had (including yearly Thousand Trails fees)
• the overall per night cost
• the overall Thousand Trails per night cost

For mileage, I keep entries in for trips for service without start/end dates.

Then for major trip planning, I make a spreadsheets by trip. It has a set of blocks per day laid out like a calendar. I then put in:

• Date
• Target campground name
• Campground address
• Mileage from previous campground
• Reservation notes, if made

And finally, we use a good ole calendar for similar use if we're out for a longer time to map out the things that we want to do. It's very similar to just above, but it has less details on the campgrounds and has entries for plans on what area attractions do we want to visit. It was important for us this past summer to make sure that we accomplished everything that we wanted to (and that still didn't fully happen!).

[RPAspey]

I'm heading to therapy for my shoulder surgery and will check into one for afterwards.

[camaraderie]

Originally Posted by ependydad

So unfortunately, I set it up to charge and then went to bed after the measurements that I took above. So I wasn't able to see the ramp down. I did check the water level before I charged it and they were fine. Per your recommendation, I also checked water levels this morning after taking it off of the charger and they appear unchanged.

I checked on the battery again this morning and the charger has switched to "charger/maintaining" mode:

Measuring the battery with and without the charger show 12.79:
From the Trojan users guide, this appears to be a 100% charge.

I'll test the battery this evening and tomorrow to see that it is staying at 12.79 or thereabouts.

And finally, the charger is an cheap charger from
Walmart. It's a Schumacher XC10. Price online shows $30, but I don't believe that I spent that much. Maybe I did.

All is good. The 12.79 V is a little bit misleading as this is why we wait 24 hours before testing with a meter after charging. This is called a surface charge...and is higher than the actual charge on the battery...you may even read into the 13V+ range with a surface charge depending on the battery and charger. I expect you will ramp down closer to the 12.7V "Full" reading but in this case it does not matter.
As to the operation of your charger...the maintenance mode will monitor battery state of charge and if it over time, falls below a certain voltage (probably 12.5 or so) it will supply a small 2amp current at around 13.4 V to bring the battery up full. Since batteries lose around 10% of their charge per month in normal temps...less in cold, more in heat.... the maintain cycle compensates for this. Personally I don't like to leave anything connected to the battery in storage. I prefer to put a real charge on it once every couple of month AFTER I check it with a meter and KNOW it needs to be charged rather than leave my batts subject to a charger failure unattended. Your choice...opinions vary on this.
Your manual also says the charger has a desulphation mode....but provides NO explanation on how to turn it on or off. My guess is that it is an ineffective pulse desulphator that is computer controlled and out of your control...BUT...would explain the short term +15V readings you saw initially.
Your charger will actually begin charging in the mid 14V range and ramp down over time to the low 13V range when the green light will come on as fully charged. I suspect that it is NOT fully charged when the green light gets tripped...but is probably in the 95%+ charged range and another few hours in the maintenance green light mode are still needed. So don't disconnect the moment you see the green light. No harm in leaving it on overnite and being sure of a 100% batt charge in the AM.

You do have an inexpensive charger but it is fine for out of the coach charging/recharging. If it ever fails or you decide to replace it... get one with about 20-30amps (assuming ONE trojan battery...double it if you get two!) and make sure it has smart 3 stage charging AND a separate desulphating cycle that is user controlled.

Best...

[RPAspey]

here's a decent looking hydrometer: Amazon.com: OTC 4619 Professional Battery Hydrometer: Automotive


your local NAPA or similar automotive supply house should also have one like it. You'll want to get a temperature from the cells, but the the built in thermometer isn't any good.


Rinse with distilled water before and after use. After rinsing, the test goes something like this, 1) open the battery cap, 2) squeeze the bulb and take in enough battery acid to float the indicator 3) squeeze the bulb to get rid of the battery fluid. 4) repeat #2 but this time get the reading where the minuscus is on the indicator, once it is floating. 5) repeat step 3. 6) close cap, record measurement and move onto the next cell. repeat at starting at step 1. 7) get a temperature from one of the center cells. use this to determine the temperature compensated Specific Gravity.

[ependydad]

Thanks guys.

[ependydad]

11-hours later, showing 12.75:



I'll recheck it in the morning. Fresh good batteries seem to have the multimeter working better (for now, at least).

And here's a monkey:

[ependydad]

I checked again this morning. Still showing a 100% charge:



Ordered my hydrometer last night.