Batteries - What the H$!! now-gctid397623

[Guest]

Couple of weeks back I posted about putting in new Batteries. I put in deep cycle flooded house battery and flooded starting battery (1000 cca). When I hooked up I could not get my charger to go from "safe" mode to flooded. I figured no big deal for now since only on shore power when in transient marinas and no plans for one soon. Well, low and behold I go to boat Tues eveining to head out for the fourth and BOTH batteries were stone cold dead!! Now MBSS was off, nothing wired directly to the starting battery except the charger. Some things are direct to house batt, like bilge pumps and CO detectors, but boat is rack kept, bilge was bone dry and I removed the fuses on the CO's when left last time (I know a lot of you don't like that but long absences create problems if I don't). So the only thing that makes sense is that the charger drained the batteries, or created a path to the starting battery if something drained the house batt. What am I missing here???

The charger is a Guest "smart charger" with led indicators for battery type. Could the charger be the culprit here. I didn't have charger on since installing the batteries, do I need to activate the charger after new batteries are installed? Manual does not mention this. To eliminate the charger during this absence, I removed the charge line to the batteries temporarily. I will be headed to the boat this weekend and see what happens.

Appreciate Ideas.......:livid:

[Guest]

trode wrote:
Couple of weeks back I posted about putting in new Batteries. I put in deep cycle flooded house battery and flooded starting battery (1000 cca). When I hooked up I could not get my charger to go from "safe" mode to flooded. I figured no big deal for now since only on shore power when in transient marinas and no plans for one soon. Well, low and behold I go to boat Tues eveining to head out for the fourth and BOTH batteries were stone cold dead!! Now MBSS was off, nothing wired directly to the starting battery except the charger. Some things are direct to house batt, like bilge pumps and CO detectors, but boat is rack kept, bilge was bone dry and I removed the fuses on the CO's when left last time (I know a lot of you don't like that but long absences create problems if I don't). So the only thing that makes sense is that the charger drained the batteries, or created a path to the starting battery if something drained the house batt. What am I missing here???

The charger is a Guest "smart charger" with led indicators for battery type. Could the charger be the culprit here. I didn't have charger on since installing the batteries, do I need to activate the charger after new batteries are installed? Manual does not mention this. To eliminate the charger during this absence, I removed the charge line to the batteries temporarily. I will be headed to the boat this weekend and see what happens.

Appreciate Ideas.......:livid:

With out seeing the wiring this is a real shot in the dark.

Any chance the batteries are somehow paralleled either directly or through another device?

Do you have a hand held DVM or volt meter? If so, disconnect one battery positive and with the switch off measure between the disconnected terminal and the common negative on the engine block. It should read 0. If it reads 12v you have a back feed somewhere. Batteries left in parallel will seesaw and flatten both batteries.

[Guest]

Went back today, after week absence and all was ok, I did not reconnect the battery charger terminals and will not until I am somewhere with shore power. I think that is the culprit. Remebering back to hook up, I recall that the charger connection to battery arced when I hooked up, that surprised me. I am beginning to think that maybe I have charger problems. Will read the maual for it and see if mentioned in there.

[Guest]

trode wrote:
Went back today, after week absence and all was ok, I did not reconnect the battery charger terminals and will not until I am somewhere with shore power. I think that is the culprit. Remebering back to hook up, I recall that the charger connection to battery arced when I hooked up, that surprised me. I am beginning to think that maybe I have charger problems. Will read the maual for it and see if mentioned in there.

Sounds like you found your problem!