I've been keeping my starting batteries on a BatteryMINDer with the setting at 2amps while in storage and I also keep the coach plugged into to a 30 amp plug. I don't disconnect anything in the coach and the battery master switch is always on and because of this I assume there is some draw - even parasitic draw.
Question: Is a 2 amp trickle charge too little amperage to keep them topped off?
Should I try for 4 or 8 amps? Thoughts. The batteries are 18 months old.
Pat
I presume the Battery Minder is connected to power and also the chassis batteries, and the 30A shore power is powering the inverter/charger which in turn is charging the house batteries. You should be fine.
If you already have a voltage sensitive relay (or add one), you won't need the battery minder.
Hi Tom,
Thanks - Yes, I have the Battery Minder charger plugged into the 110 outlet in my wet bay compartment on the coach and my 30 amp into the shore power which feeds the inverter/charger. I assumed that the charger/inverter does not cross connect to the engine battery unless I have the boost switch on - which I figured draws power - so I just keep them both separate.
My starter batteries have been low that last few times and I have had to use the boost switch to start - not sure why.
Pat
I think you have answered your own question.
The way you have things set up and connected should be working fine, IF the 2 amp setting on the trickle charger is sufficient.
BUT, your start batteries "have been low the last few times..."
SO, it seems the 2 amp setting is
not sufficient, which would suggest that a slightly higher setting is called for.
If it was me, I'd try the 4 amp setting, and see how that works. If that doesn't keep the start batteries topped off, then try 8 amps.
What kind/type of start batteries, and how many?
Is it only the start batteries that are showing low voltage?
How often do you get by the coach to check on things?
Thank you,
I keep it at a storage facility where they keep it plugged in (but I have been there in the past when they had another coach plugged into my outlet), so perhaps it was not always plugged in. I did some further research on my charger and it recommends 4-8 amps for RV - hopefully, this can be a starting point. The batteries are called "American Eagle" never heard of them - it states that they are from Escondido, CA. (photo)
Currently, my BatteryMINDer shows the batteries at 1/2 - so they are definitely low. I'll see what 8 amps does for the next 36 hours.
My coach batteries (3 AGM) are great and my Xantrex 3000 keeps them in good shape.
Thanks for all the input.
You might consider moving the black charge connection from the front battery negative to the rear battery negative post. This allows the charger to span the battery bank. Many consider this a superior arrangement.
The same applies to the black and red power cables to the engine. Both are connected to the rear battery. If you chose to follow this suggestion, then move one of them to the other battery post to allow the load to span the bank.
I just put a jumper from HWH panel lighter plug to dash lighter plug. Fused each end at 5 amps at the jumper plug. LED to show both have power. Keeps both sets of batteries (conventional engine and AGM house) up with our solar in use or on shore power. Jumper is removed when the engine is running, coach is moved or underway. Have been using this for years with no problems.
You have to insert the plug straight into the outlet or it will pop the 5 amp fuse.
Tiny white spots in photos are from sanding outside that blew in open window.
Pierce
Thanks for the great input.
Pat
Pierce,
Not saying your "jumper" idea isn't clever - it is. But, there is one problem with using this device
on a coach in storage. If shore power is lost to the coach,
and there is a substantial drain (of any kind) on
one of the battery banks, then
both battery banks will be discharged.
Exactly the same problem would occur if a coach owner leaves the boost switch energized to keep both battery banks charged. As you well know, this practice is discouraged on this Forum, lest the owner be left unable to start either engine due to dead batteries.
Of course, as long as the coach is being monitored on a frequent basis, neither charging method is likely to get one in trouble. Still, I personally believe it is prudent to keep the battery banks separated and thereby (hopefully) avoid a inconvenient "no start" situation.
Chuck,
If both battery banks are fully charged, totally disconnecting the batteries is the best way insure they make it through the winter in the north. I bought a couple extra AGMs that I put on the shelf. Still fully charged over a year later. If fully charged, batteries will not freeze. Conventional batteries won't make it a year and will self discharge in a month or two in summer. That's why the DieHard commercials showed the battery incased in ice throughout the winter with full charge when the ice was chipped away.
When not traveling, our coach is stored at our house and has either the solar on or shore power. The solar can stay on year after year without a problem but when covered/garaged, it has to be plugged in.
Pierce
My experience is that having any battery at 50% charge for any length of time causes a loss of capacity and/or service life.
To avoid this the rv industry has switched to auto combiners
ML-ACR Automatic Charging Relay with Manual Control - 12V DC 500A - Blue Sea... (https://www.bluesea.com/products/7622/ML-ACR_Automatic_Charging_Relay_with_Manual_Control_-_12V_DC_500A)
Great articles for trickle chargers. My question is it ok for me to plug into a 15a circuit for the Canadian north winters to keep the house batteries charged through my inverter or is the amperage to low? I do not have a 30a plug-in available. Also do I charge the starter batteries Left in the coach (3) with a battery minder with three connectors or do I remove them and put them in a in heated garage on tenders?
15 amps is fine for charging the batteries and leave your battery minder on. As long as the batteries are fully charged the cold
weather won't bother them,
If I was storing my coach away from home and the place I was storing it unplugged and then "hopefully" plugged it back in, I would be worried. I would charge the batteries to a full charge then disconnect them to isolate them but leave the charger on.
Your coach probably has more parasitic loads than you would think.
Trying to charge the batteries can fail the trickl charger.
Two amps should keep both house and engine batteries charged. It does on ours. I just do a lighter to lighter jumper at the dash. Keeps both around 13.5 volts. I use a regular battery charger with the switch set to 2 amps.
Batteries with a charge won't come close to freezing. Batteries disconnected when charged in Winter will still have a full charge in Spring. Remember the Die-Hard ad with the battery frozen in an ice block? Just the opposite in warm weather where a battery may discharge in a month depending on type.
Pierce