2002 GEM doesn't charge 100%

Hello my name is Adam, I just bought a 2002 Gem. The batteries are two years old standard deep cycle batteries flooded. When I plug it into the house after several days it only gets to 85%, and when I drive it drains pretty quickly maybe over the span of an hour . I bought a battery tester and all the batteries pass, the cold cranking amps are all pretty high. Every battery voltage is above 12.7. Total volts is 77. Any ideas would be appreciated

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Your charger is probably timing out before the batteries reach a full charge. Check to make sure it is set for Flooded batteries and not GEL. Remove each cable and clean terminals. Fully charged batteries will be over 80 volts at charger shut down.

You have a common performance description for flooded batteries charged on the Gel charger setting.

Since you have flooded batteries you can check each cells specific gravity with a hydrometer.

Specific gravity is thhe gold standard for flooded batteries.

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Thank you very much. Where is this setting located?

Zivan or DeltaQ charger?

It’s a vivan charger

Sorry it’s a zivan battery charger

Many Zivan chargers have a adjustment dial to change settings. Many early ones do not because flooded batteries were the only type available.


Electric Conversions Can tell you what features your charger has built in if you give them the serial number.


Checked the setting on the Zivan charger. It does has settings. It has 3 setting for Trojan batteries. I put it on the middle one.

It charges the batteries to 100%. If i let it sit there plugged in, it drains to 75% and stays there.

Even if I unplug the charger it will drain to 75%

Did you ever figure out the problem? My 2001 has new charger and charges to 100%. If I unplug the charger and plug it back in right away, it goes down to 80 %. Can’t figure why?

That’s normal. The charger programming evaluates batteries differently than the SOC on the dash. You can actually take advantage of that to equalize your batteries (charge to a higher voltage, give a lagging battery or cell a chance to catch up) by just plugging your charger back in for a second cycle after the first one completes.