Batteries Are Hot. Amp Meter Showing Zero

[Joe Mullee]

I just came aboard and the batteries were showing "zero" on the amp meter. I looked at the TrueCharge 10 Amp Multi-Stage Battery Charger and it was giving out a light sequence that suggests the batteries are damaged. The battery selector switch was set on "ALL". When I switched between #1 and #2 the amp meter remained at "zero". I tested both the starting and house bateries with the multi-meter and got under 6.6 volts on both. I have three house batteries (gel) run in parralel that amount to 291 AH and are seven years old. The middle battery in this group was hot to the touch. The starting battery is isolated from the house batteries.

The first thing I've done is turned off the battery charger. Is there anything else I should be doing from a safety standpoint as I try to figure out this problem? Should I unhook the cables that parralel the house group? The charger has been turned off for about an hour and the middle battery is still hot.

A little over two weeks ago I left on a six day sail and had no issues. My Yanmar 3GMF has the standard 35 amp alternator. I spent four of the nights on the hook. I returned nine days ago at which time I turned on the battery charger when I closed up. Right before I left I installed a new refrigeration unit. When I left the boat I left the refrigertor switched on the the DC side. The unit is a Norcold which has an automatic AC/DC relay switch so I don't think it would have caused this problem. The refrigerator was plenty cold when I got here indicating it was running off the AC side.

Any help, suggestions, advice on what caused the problem and how to fix it is greatly appreciated.

Joe Mullee

 

[kenn]

It's good that you've disconnected charging, til the problem's sorted out.

I just came aboard and the batteries were showing "zero" on the amp meter.

I have no idea what you're trying to say here. What meter are you looking at, and what does it normally show when the boat is on charge?

 

[Dan Johnson]

Joe...

It doesn't look good for your batteries. Your charger may have "cooked" them, being that they are gel cell ones. That they are "hot" shows a strong current flow may have been taking place.

Does your charger have a different setting for gels versus wet cells?

I suspect the fridge ran on DC until it could no longer do so, thereby discharging your batteries if your charger wasn't able to "float" the use or had quit working.

I think your fix may be to remove the batteries and have them looked at by a dealer doing a charge and load test to see if they are still good. Also, it may not be a good idea to leave the charger on as long as you did--think about using an heavy duty clock timer to control the daily charging time rather than being in use constantly.

 

[Don S/V ILLusion]

Rather than reiterate, see previous thread entitled "Dead Batteries". Although not a rule, most batteries generally don't last 7 years so if it's any consolation, you got your money's worth.

 

[kloudie1]

Sounds like the hot one has packed it in, Joe.. disconnect all paralleling cables and measure volts .. It should be easy to see that the hot one (most likely) is toast.. It may have killed the others as well at that age.. The TrueCharge has a tough time acting as a power supply and can over charge batteries if operated that way.. I think ithe manual talks about that.. There is a switch that lets it do that if ya want to, I think.. I don't understand how the start batt could be drawn down if it is isolated..??

 

[Joe Mullee]

Took Out The "HOT" Battery

I took the "HOT" battery out of the house bank and immediately the voltage went up to 9.3 from the previous 6.4. I put the charger back on and will monitor the voltage every 30 minutes with the multi-meter.

Dan: "IF" the charger was working correctly would it cook the batteries? I thought that was the whole point of the Bulk-Absorb-Float feature. It's been flawless for ten years. Maybe it's breaking down.

I still don't understand why the starting battery also died. Would it be obvious to say that it's NOT isolated from the house? When I initially checked the voltage it read exactly what the house batteries read at 6.4 volts. When I took the hot battery out of ther house bank and tested the house and the starter seperately they each read 9.3 volts.

Thanks.

 

[Dan Johnson]

Joe...

wet batteries are charged at a higher voltage than gels, which is why I asked about a switch setting. If it's worked fine previous years, there should be no difference this year. If the batts are over 5 years old, you got your money's worth. At 7 years you were living on borrowed time.

I had a Guest 5/10 "smart" charger on the boat when I bought it. At the end of the second season on a weekend in the slip, I noticed the lights were dimmer the second night, despite cycling the battery charger on and off during the day. When turned on I found no voltage increase on either battery.

I pulled the charger (no easy task as it lives down in the "basement" with the batteries on my H34) and took it home for testing. Dead as a doornail. Replaced it with the newer equivalent and had no problem ever since. Hence the reason for me asking about the charger working.

"If" it was working correctly, the condition you experienced could be attributable to the battery reaching the end of its life span, not the charger going on the fritz. Your last post seems to indicate that.

To jump up to 9.3 volts indicates the "hot" battery was pulling the other house and starter ones down (they must be cross connected to have done so, which I suspect the "ALL" switch setting did as your house batteries are wired in parallel). But to still be at 9.3 volts indicates a fully discharged battery. Hope the charging session afterward brings them up but suspect it will only be temporary. That deep a discharge on such old batteries surely will spell their death nell. They aren't likely to recover at that age.