Charging choice, under or over volt?

[BradKW]

I got my Morningstar TS-60 controller hooked to the L16 24v battery bank, and via internal dip switches I choose the charging profile.  Until I get a PC hooked into the system and can create a custom charging profile (will be awhile), I have to choose between the two closest matches to Trojan specs.

Trojan want 29.64v at bulk, 27v at float. I can either pick the MS L16 setting of 30.8v Bulk / 26.8v Float, or next closest match is 29.1v Bulk / 27v Float. I'm currently running the second, lower volt profile, but thought I'd ask.

Also worth mentioning that when I swap to the lower voltage profile, it greatly reduces the amps/watts that I see displayed on the remote monitor. Switching from the higher, L16 profile this morning took it from 600 watts showing, to 300 watts steady. Dunno what to make of that.

 

[John61CT]

Higher the voltage the higher amps absorbed.

I'd say a little under is better than a whole volt over.

But why not contact Trojan tech support?

Get the PC asap in any case.

 

[Trebor English]

A charging voltage and current powered by plug in just keeps on going. A solar source shuts off when the sun goes down. Where a plug in might damage a battery a solar shuts off.

Many (most) Trojan products are charged by plug in chargers. Golf carts and floor scrubbers usually are charged by "automatic" chargers that repeat the same sequence every day. They can charge right up to the same limits every time. That's where Trojan recommendations come from.

With flooded batteries you can replenish lost water so overcharging is not a horrible mistake. You can check with a hydrometer to see how it is actually doing. Give it a week and let the water use and hydrometer be your guide.

 

[John61CT]

Ah yes that's what's great, about old-school FLA. But wow, 120 lbs each 6v, whole lotta led!

 

[SternWake]

Remember, recommended specs are for 77F.  The morningstar have a battery temp sensor?


Until you makea cutom profile,
If cycling deeply I'd go over, if cycling lightly I'd go under.

if there is little chance of getting to full by afternoon, over
All the time in the world, under

 

[BradKW]

It does have a temp sensor. Something I learned today while reading instructions is that temp sensor is only needed if battery temps will be different than the CC, basically implying that if both things are in the same spot, no need for sensor. Which I found surprising, as I assumed that the sensor was actually reading the battery via the terminal connection, but sounds like it's more a measure of ambient.

Regardless, I am using it...batteries will not be in same location as CC. Just thought that was interesting...

 

[John61CT]

No don't rely on ambient, should be reading right off the terminal.

Not just compensation, backing off when overcharging.

 

[SternWake]

It does have a temp sensor. Something I learned today while reading instructions is that temp sensor is only needed if battery temps will be different than the CC

These instructions imply the only charging source would be the solar, which in general will not be able to charge at a high enough rate to significantly raise the temperature of the batteries.

But high rate discharging also can raise their temperature, and being such a dense mass, will also hold heat store cold much longer than ambient temps.  The charge controller also gets warm, so an Ambient temp sensor is a bit asinine, unless it is not inside the controller nor above it.

My biggest regret regarding my solar is not spending the extra for the solar controller with the BTS.  it was only 35$ extra at the time.  Worst 35$ I ever 'saved'.

 

[ccbreder]

I don't think you have to worry about solar and charge profiles that are close to what is recommended. If open cell batteries, keep check of the water untill you have a pattern of use.

 

[jonsun]

yeah it being winter I would probably over-volt and keep close watch on the water level. Maybe try a resistor in-line.