Batery Trickle questions?

[bigskymudflaps]

I understand that it's good to put the batteries on a trickle over the winter. I am planning on using a charger that will trickle a low amp charge of about 1.5amps and will go into float (turn off) after the battery reaches full charge. I've found a good charger, but I have a few questions the guys at the automotive shop couldn't answer.

1. Can I charge two batteries with the same charger?
2. Can I charge two different batteries with the same charger (I have a large house and a smaller starting battery)?
3. Do I disconnect all the boat battery wires when charging both batteries?
4. Do I wire the batteries in series or pararell when I charge them with one charger?
5. Can I connect the charger battery isolator?

The pictures are of my batteries. The pro ecl, has been sweet. The cranking is pretty standard.
The photo of the isolator is similar to mine, mine is for two batteries, three poles.

[chpthril]

1) Yes, but its output will be divided between two batteries that are used completely different and would more then likely start out at a different state of charge. This would not be a huge factor once both are brought up to full charge and then just maintained during the off season

2) Both are considered SLA (Sealed Lead Acid), so yes, two batteries of the same type can be charged together.

3) With a charger of that low of an output, I see n need to disconnect.

4) in order to maintain 12V, they need to be connected parallel.

5) Yes, but with a .7V drop across the typical diode isolator, you would loose quite a but of the chargers output.

I would get a 2nd charger and charge both independently of each other.

[IDBoating]

An alternative to a second charger is simply to manually move the cables every so often. I have a single high-end charger, and during the off-season I keep all of my batteries in the "mechanical room" of my house (where the furnace, water heater, etc. are) so they stay at a comfortable temperature. Whenever I think about it, I open the door and move the cables to the next battery in rotation. I do this all winter. This means no battery goes more than a few days without at least 24 hours on a charger, and I don't move the cables until the charger indicates that the currently connected battery is fully charged.

Simple solution that costs nothing. Just an idea.

[raythompson]

Or get a charger that support multiple batteries. I have one that supports two batteries. The charger is kept in the boat as it is sealed, permanently connected to the batteries. Come winter I just plug in the charger and am done with it until spring. I do not disconnect the batteries, just use the battery switch in the off position.

This is the charger that I use

[IDBoating]

I do not disconnect the batteries, just use the battery switch in the off position.

Does your battery switch disconnect both batteries from the boat's systems? Mine, as shipped from the factory, did not.

[raythompson]

Does your battery switch disconnect both batteries from the boat's systems? Mine, as shipped from the factory, did not.

Everything is disconnected with the exception of the automatic bilge pump circuit. No lights, no blower, nothing except the pump. Makes sense to disconnect everything but the bilge pump.

[IDBoating]

Everything is disconnected with the exception of the automatic bilge pump circuit. No lights, no blower, nothing except the pump. Makes sense to disconnect everything but the bilge pump.

I totally agree, but on some Tiges (mine and Ewok's, for example) the single battery switch only controlled the engine battery. The "house" battery, which powers virtually everything else, was hardwired with NO BATTERY SWITCH. You had to kill both main circuit breakers under the driver's console to (hopefully) isolate it.

Both of us have added a second, formal house battery switch next to the engine battery switch so we can easily know for certain that both batteries are completely isolated (except for the bilge pump(s), of course).

Hence my question. I was amazed that my boat had a battery that wasn't protected by its own battery switch, and wondered if yours is the same way.

[Duncan]

I totally agree, but on some Tiges (mine and Ewok's, for example) the single battery switch only controlled the engine battery. The "house" battery, which powers virtually everything else, was hardwired with NO BATTERY SWITCH. You had to kill both main circuit breakers under the driver's console to (hopefully) isolate it.

My 09 is like this. I have to kill the battery switch and both circuit breaker switches to turn off all batteries (three house batteries and one crank battery).

[IDBoating]

My 09 is like this. I have to kill the battery switch and both circuit breaker switches to turn off all batteries (three house batteries and one crank battery).

Exactly, and many people don't realize it. That's why I brought it up.

As for the second battery switch, I felt it was too easy to forget the out-of-sight, out-of-mind breakers so I put in a second battery switch right next to the first one. Now the breakers are used solely for what they're designed (open if an overcurrent condition occurs) and not as everyday switches.

[TeamAllen]

You might want to check with the battery manufacture. When I kept going through Optima Batteries every few years, I called and asked. They told me to use a trickle charger not exceeding .75A. I found the Battery Tender Junior by DelTran does just that. After switching to that battery charger, my last battery lasted 8 years and was still working, but made me nervous and I just switched it out before this season to be safe.

Here is some good info about charging in series and parallel
http://batterytender.com/resources/c...s-chargers.htm

[IDBoating]

Yep, Battery Tender Jr. is what I have and rotate through all of my batteries during the off-season. I recommend it!