Boat Battery Will Not Charge
Marine
- Sponsor
- OPTIMA Batteries
- Location
- Glendale, WI
Do you have a boat battery that will not charge? We can help you sort out what might be going on and either help you get your boat battery charged or determine if it needs to be replaced. The first thing to do when trying to charge a boat battery is measure voltage. This gives you a baseline and lets you know how much energy is in your boat battery's electric fuel tank.
A fully-charged 12-volt lead-acid battery, like the OPTIMA 34M BLUETOP should measure at least 12.6 volts and some batteries, like the OPTIMA BLUETOP (except the 34M BLUETOP) may measure as much as 13.0-13.2 volts. Some battery chargers, like the 400 or 1200-series OPTIMA Chargers have the ability to provide pre-charge voltage status. If your battery charger does not provide that functionality, you can always measure battery voltage with a voltmeter, which can be picked up at any auto parts store.
You should also make sure your battery charger is functioning properly. While that is an often overlooked step, a broken battery charger, blown fuse or tripped circuit breaker could end up being the culprit behind your battery charging woes.
If your boat battery voltage is below 10 volts, your battery is likely very deeply-discharged and while OPTIMA Chargers can recover batteries that have been discharged as low as 1.25 volts, that's not the case for every battery charger. Some chargers will not work on batteries that have been deeply-discharged, even if they are showing 10 volts or more. Other chargers may work for a brief period of time, but if they do not measure a minimum voltage level (usually somewhere above 10.5 volts), they may turn off automatically and/or display at "01" fault code. In those instances, a parallel charging technique (explained here), may allow those older style chargers to recover a deeply discharged battery.
Generally speaking, 12-volt battery cells will measure about 2.1 volts per cell, with six cells being in each case. If your boat battery has an issue with one of its cells, the voltage may never get above 10.5 volts (12.6-2.1), even after being charged. If your boat battery measures between 10.0 and 10.5 volts, it may be time to take the battery to a battery professional and have it load-tested. Most battery retailers, like auto parts stores, will offer this service for free.
Having your battery load-tested is also an option to consider, if you have exhausted all other possibilities. A battery professional will typically measure voltage and attempt to charge a battery before performing a load test. If they cannot get the battery charged to provide an accurate test or the battery fails a load test, then it will be time to replace the battery.
Many boat battery issues can ultimately be traced back to poor or no maintenance of the boat battery when it is not in use. The best thing you can do to maximize boat battery performance and lifespan is to keep battery voltage properly-maintained whenever possible, with quality battery maintenance device. We're so confident this is true, we will add an additional year of free replacement warranty coverage to your OPTIMA battery, if you purchase it from us directly and buy a 1200-series OPTIMA charger at the same time.
A fully-charged 12-volt lead-acid battery, like the OPTIMA 34M BLUETOP should measure at least 12.6 volts and some batteries, like the OPTIMA BLUETOP (except the 34M BLUETOP) may measure as much as 13.0-13.2 volts. Some battery chargers, like the 400 or 1200-series OPTIMA Chargers have the ability to provide pre-charge voltage status. If your battery charger does not provide that functionality, you can always measure battery voltage with a voltmeter, which can be picked up at any auto parts store.
You should also make sure your battery charger is functioning properly. While that is an often overlooked step, a broken battery charger, blown fuse or tripped circuit breaker could end up being the culprit behind your battery charging woes.
If your boat battery voltage is below 10 volts, your battery is likely very deeply-discharged and while OPTIMA Chargers can recover batteries that have been discharged as low as 1.25 volts, that's not the case for every battery charger. Some chargers will not work on batteries that have been deeply-discharged, even if they are showing 10 volts or more. Other chargers may work for a brief period of time, but if they do not measure a minimum voltage level (usually somewhere above 10.5 volts), they may turn off automatically and/or display at "01" fault code. In those instances, a parallel charging technique (explained here), may allow those older style chargers to recover a deeply discharged battery.
Generally speaking, 12-volt battery cells will measure about 2.1 volts per cell, with six cells being in each case. If your boat battery has an issue with one of its cells, the voltage may never get above 10.5 volts (12.6-2.1), even after being charged. If your boat battery measures between 10.0 and 10.5 volts, it may be time to take the battery to a battery professional and have it load-tested. Most battery retailers, like auto parts stores, will offer this service for free.
Having your battery load-tested is also an option to consider, if you have exhausted all other possibilities. A battery professional will typically measure voltage and attempt to charge a battery before performing a load test. If they cannot get the battery charged to provide an accurate test or the battery fails a load test, then it will be time to replace the battery.
Many boat battery issues can ultimately be traced back to poor or no maintenance of the boat battery when it is not in use. The best thing you can do to maximize boat battery performance and lifespan is to keep battery voltage properly-maintained whenever possible, with quality battery maintenance device. We're so confident this is true, we will add an additional year of free replacement warranty coverage to your OPTIMA battery, if you purchase it from us directly and buy a 1200-series OPTIMA charger at the same time.