New smart charger irregularities -- your thoughts?

[LuisP]

Recently, my old Trace U2512 inverter-charger gave up the gost and I replaced it with a new 3000 watt - 150 Amp marine smart inverter-charger. I am experiencing some irregularities an would appreciate feedback to understand or resolve what I am seeing.


I am charging a house bank consisting of 2 8D AGMs and a starter 4D AGM through an Ample Power eliminator.


The two irregularities are these: (1) the voltage reading on new unit's panel is one-tenth of a volt higher than what I measure with a DVM at the unit's terminals and what my battery monitor reads at the batteries. (2) the charging stage algorithms for the AGM batteries appear to function as expected, but after about 24 hours in FLOAT mode (~13.8 V temperature compensated), it jumps to ~14.5 - 14.8 V Float.


What could be causing this behavior? Of course, I am reluctant to leave the batteries at such a high FLOAT voltage to see if it reverts to the 13.8 V level, and have opted to turn off the charge function when that happens. I am about to explore possible interactions with the eliminator and smart alternator circuits by going directly to each of the batteries from the charger and welcome your suggestions and advice.

 

[twistedtree]

Accuracy in many voltage meters is quite poor. Give or take a 10th of a volt seems quite common.


Many chargers have a "re-bulk" feature where after a certain amount of time the charger will start another bulk charge cycle. That would be my first guess about what you are seeing. Check the manual to see what they say. If this is what's happening, it shouldn't last longer than the chargers absorb cycle time, which can be anything from a few minutes to a few hours.

 

[Bmarler]

Recently, my old Trace U2512 inverter-charger gave up the gost and I replaced it with a new 3000 watt - 150 Amp marine smart inverter-charger. I am experiencing some irregularities an would appreciate feedback to understand or resolve what I am seeing.


I am charging a house bank consisting of 2 8D AGMs and a starter 4D AGM through an Ample Power eliminator.


The two irregularities are these: (1) the voltage reading on new unit's panel is one-tenth of a volt higher than what I measure with a DVM at the unit's terminals and what my battery monitor reads at the batteries. (2) the charging stage algorithms for the AGM batteries appear to function as expected, but after about 24 hours in FLOAT mode (~13.8 V temperature compensated), it jumps to ~14.5 - 14.8 V Float.


What could be causing this behavior? Of course, I am reluctant to leave the batteries at such a high FLOAT voltage to see if it reverts to the 13.8 V level, and have opted to turn off the charge function when that happens. I am about to explore possible interactions with the eliminator and smart alternator circuits by going directly to each of the batteries from the charger and welcome your suggestions and advice.

a tenth of a volt is quite a bit. but it can be within the resolution of a device depending on it's quality, or if it's a true rms meter, or some other sensor issue. not a huge worry as long as you know it's happening and can program your own float voltage.
the jump to 14.5 seems more like it's either going back into absorption or bulk charging. there might be a timer that needs set up regarding the time value it waits to charge after float.
you may also want to check the batteries to be sure one of them hasn't failed. i recently had a problem with one failed battery that was pulling power from the rest of the bank and keeping the charger from going into float mode.

 

[LuisP]

Thanks, Bmarler . . .
I agree on both points. However, the charger panel reads 14.5 V FLOAT, and I have not found anything in the manual to address the alternative you mention.

 

[Bmarler]

also have a look at the recharge voltage setting. if it's too high it will make the charger jump out of float mode.

 

[Bmarler]

Thanks, Bmarler . . .
I agree on both points. However, the charger panel reads 14.5 V FLOAT, and I have not found anything in the manual to address the alternative you mention.

you didn't mention the model of charger. it might help if someone has the same unit.

 

[twistedtree]

Thanks, Bmarler . . .
I agree on both points. However, the charger panel reads 14.5 V FLOAT, and I have not found anything in the manual to address the alternative you mention.

Very interesting. I think a call to the manufacturer is in order.