troubleshoot battery setup

Finally got my new battery in and wired up. Everything seems fine, but... plugged in my Battery Tender PowerTender Plus and the Yandina C100 kicked into overload. ARgh!! Anyone have any thoughts or ideas what to check?

Wiring schematic is attached. The C100 has a blue lead for gel-type batteries I've connected that supposedly limits the charge, which I've connected to the starter positive battery terminal per instructions. The charger I opted for was recommended by the Battery Tender support folks when I forwarded my proposed setup (Power Tender Plus http://batterytender.com/product_info.php?products_id=7). The support person thought that model should be able to charge the starter battery normally and once charged, maintain the 13.3v needed to engage the C100 in order to charge the House battery. Doesn't quite seem to be working as planned. Any ideas what I might check?


(Message edited by superairdawg on May 16, 2006)

whups... image attached.

Okay, it looks to me like you have the "blue" wire connected wrong.

Are both batteries the same type? That is, are both flooded lead acid, or both Optima, etc?

If both batteries are the same then just disconnect the blue wire and leave it open. The purpose of that wire it sense the voltage on the "Auxiliary" battery and disconnect when the voltage gets too high. That would allow you to have a flooded lead acid battery for starting and a Gel battery for house.

In that configuration the blue wire would attach to the "house" battery, not the starting battery. The way you have shown it hooked up it will probably complain about. The reason is that it can't disconnect from the source of the too high a voltage because the blue wire is connected directly to the charger.

Rod - thx for reply! When you going to put your PayPal button up?


My starter is a D34 yellow top and my house is a D34M blue.

Now that I'm scrutinizing the C100 instructions I believe you might be right on the 'blue' wire. I'll try disconnecting to see if that solves it.

Stay tuned...

Rod is right. I asked Yandina the same question with same response.

Confirmed -- Rod is RIGHT! Unhooked the blue wire and now my Tender is merrily charging along, with the C100 indicating "combined" mode. Hopefully I can extend the 'blue' wire clear up to the correct battery.

I feel a little embarassed I missed that, but am appreciative of the assist!!

Joe:

First off, why do you think you need the blue wire? It should only be necessary if the battery connected to the engine was a flooded lead acid (good old fashion battery) and the other battery was something different AND you wanted to treat it more gently.

If you had a GEL battery then this would be fairly important. I really doubt that you have a GEL battery, they are VERY expensive and have damn little storage. AGM batteries (Optima) are much more common. While you really don't want to connect batteries directly together unless they are identical (including age) combining an AGM and flooded is okay as long as you don't exceed the rating of the AGM.

For the alternator this shouldn't be a problem because it shouldn't put out more than 14.2 volts. A small "tender" type charger shouldn't be any problem either as it probably wouldn't put out a higher voltage at a significant current.

Where you can get into trouble with an AGM battery is when you have a really high powered charger. For example, I have a 2000 watt inverter that can pump out 40 amps in charge mode. The charger has an "equalize" mode that you can request that really drives the batteries hard to "equalize" them. This drives out a lot of current to a very high voltage. It is hard on a flooded lead acid and very bad to a AGM battery.

I doubt your battery charger does that, and none should do it without you specifically telling it to.

If you really need the blue wire you should be able to connect it to the wire that leads to the battery, it isn't really necessary to run it all the way up to the battery.

I'm not sure why I was under the impression Optimas were gel-type batteries. Didn't realize they were absorbed glass mat. Actually, that's good news since it means I won't be overcharging my starter battery, either.