Disconnecting Inverter for coach battery change

[Moonmanvt]

2006 Roadtrek Adventurous...After numerous testing procedures(not only electrical but my knowledge from a previous life), I have found the coach battery holds enough charge to power the Fantastic Fan for about 20 seconds before dieing. So, when changing the coach battery how does one "disconnect the inverter"? And, since I never plan on using 120v unless we are plugged in, where should I leave the switch on the inverter?

[booster]

Originally Posted by Moonmanvt

2006 Roadtrek Adventurous...After numerous testing procedures(not only electrical but my knowledge from a previous life), I have found the coach battery holds enough charge to power the Fantastic Fan for about 20 seconds before dieing. So, when changing the coach battery how does one "disconnect the inverter"? And, since I never plan on using 120v unless we are plugged in, where should I leave the switch on the inverter?

If you are never going to need 110v power without shore power, I would leave the inverter itself in the OFF position. If it is one that has a remote on switch, like Tripplite IIRC, if the inverter is set on REMOTE everything is the same but it can get turned on accidentally pretty easily. No reason to use any power to it if you are never going to use it.

[markopolo]

Assuming it's a Tripp Lite inverter/charger

1. When replacing the battery turn the inverter off as Booster noted. You do this on the inverter/charger itself (not on the remote). It's a 3 position switch.

2. If never wanting to use the inverting function then leave the 3 position switch in the charge only position on the inverter/charger itself. If you have the 2 position remote switch then off is the same as charge only.

[booster]

Originally Posted by markopolo

Assuming it's a Tripp Lite inverter/charger

1. When replacing the battery turn the inverter off as Booster noted. You do this on the inverter/charger itself (not on the remote). It's a 3 position switch.

2. If never wanting to use the inverting function then leave the 3 position switch in the charge only position on the inverter/charger itself. If you have the 2 position remote switch then off is the same as charge only.

OOps forgot about the off being everything off and charge only being inverter off on a Tripplite. What Marko says. The charge only position is the one that the remote can be easily left on and drain power as many of the remotes don't have an indicator light. When we had that setup the inverter remote switch was right below an identical porch light switch so go accidentally on a couple of times.

[gregmchugh]

And, if you switch from wet cell to AGM leave the battery type as wet cell. Both RT and TrippLite support have given the wrong recommendation to use the gel setting.

[rowiebowie]

Originally Posted by gregmchugh

And, if you switch from wet cell to AGM leave the battery type as wet cell. Both RT and TrippLite support have given the wrong recommendation to use the gel setting.

I have a '2012 Tripplite RV750UL charger/inverter and have been thinking of going back to AGM just for the purposes of not having to check water levels. Are you saying to leave dip switch setting to wet cell even if using AGM's or just on his model charger?
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[gregmchugh]

Originally Posted by rowiebowie

I have a '2012 Tripplite RV750UL charger/inverter and have been thinking of going back to AGM just for the purposes of not having to check water levels. Are you saying to leave dip switch setting to wet cell even if using AGM's or just on his model charger?
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For the TrippLite there are limited battery type choices with no AGM choice, the wet cell choice has charge voltages closest to typical AGM requirements. Other chargers have specific AGM options.

[rowiebowie]

Originally Posted by gregmchugh

For the TrippLite there are limited battery type choices with no AGM choice, the wet cell choice has charge voltages closest to typical AGM requirements. Other chargers have specific AGM options.

Checked my Tripplite manual for setting options. Has one for "Wet Cell (Vented) Battery" which is designated as "Factory Setting" and another for "Gel Cell (Sealed) Battery". I'm running wet cells but incorrectly assumed if I went to AGM's I would need to change to the "sealed" setting. Thanks for the explanation.
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[gregmchugh]

Originally Posted by rowiebowie

Checked my Tripplite manual for setting options. Has one for "Wet Cell (Vented) Battery" which is designated as "Factory Setting" and another for "Gel Cell (Sealed) Battery". I'm running wet cells but incorrectly assumed if I went to AGM's I would need to change to the "sealed" setting. Thanks for the explanation.
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It was common for both Roadtrek and TrippLite support to tell people to use the gel setting for AGM based on the info in the manual which doesn’t give the actual charge voltages for either setting. Once the charge voltages were revealed it was clear that the gel setting was only for actual gel batteries not AGM. They never updated the charger with an AGM profile so wet cell is the best you can do.

[Knit]

My Tripplite RV750ULHW manual explicitly says the switch setting is for AGM/Gel cell. So the advice here is to go against what the manual says?
IMG_0418.jpg

I asked their support once about charging voltages and this was their reply

Bulk Charge - The first stage of 3-stage battery charging. Current is sent to batteries at the maximum safe rate they will accept until voltage rises to near (80-90%) full charge level. Voltages at this stage typically range from 10.5 volts to 15 volts. There is no "correct" voltage for bulk charging, but there may be limits on the maximum current that the battery and/or wiring can take.

Absorption Charge: The 2nd stage of 3-stage battery charging. Voltage remains constant and current gradually tapers off as internal resistance increases during charging. It is during this stage that the charger puts out maximum voltage. Voltages at this stage are typically around 14.2 to 15.5 volts.

Float Charge: The 3rd stage of 3-stage battery charging. After batteries reach full charge, charging voltage is reduced to a lower level (typically 12.8 to 13.2) to reduce gassing and prolong battery life. This is often referred to as a maintenance or trickle charge, since it's main purpose is to keep an already charged battery from discharging. PWM, or "pulse width modulation" accomplishes the same thing.

[markopolo]

Originally Posted by Knit

My Tripplite RV750ULHW manual explicitly says the switch setting is for AGM/Gel cell. So the advice here is to go against what the manual says?
Attachment 7533

I asked their support once about charging voltages and this was their reply

Bulk Charge - The first stage of 3-stage battery charging. Current is sent to batteries at the maximum safe rate they will accept until voltage rises to near (80-90%) full charge level. Voltages at this stage typically range from 10.5 volts to 15 volts. There is no "correct" voltage for bulk charging, but there may be limits on the maximum current that the battery and/or wiring can take.

Absorption Charge: The 2nd stage of 3-stage battery charging. Voltage remains constant and current gradually tapers off as internal resistance increases during charging. It is during this stage that the charger puts out maximum voltage. Voltages at this stage are typically around 14.2 to 15.5 volts.

Float Charge: The 3rd stage of 3-stage battery charging. After batteries reach full charge, charging voltage is reduced to a lower level (typically 12.8 to 13.2) to reduce gassing and prolong battery life. This is often referred to as a maintenance or trickle charge, since it's main purpose is to keep an already charged battery from discharging. PWM, or "pulse width modulation" accomplishes the same thing.

Knit - It is interesting to see that and it helps explain the ongoing confusion around this.

The reply you got looks to have been directly copied from this book: https://books.google.ca/books?id=p57...A142&lpg=PA142

It's a very generalized theory of 3 stage charging and not at all specific to your particular charger. Disappointing that they'd send that ........

I have PDF versions of two Tripp-Lite manuals. The first covered the RV612 that came in my '04 Roadtrek and the second manual has the addition of the RV750 that came later. Neither mention AGM in the switch position section. Both have:

Battery Type Switch Position
Gel Cell (Sealed) Battery Up
Wet Cell (Vented) Battery Down (factory setting)

Both manuals state the voltages related to the switch positions:

Common Specifications for All Models • Acceptance Volts VDC: Selectable 14.4 V / 14.2 V - Wet / Gel • Float Volts DC (w/gel): 13.3 V (13.6 V) • ·

You only have the two choices so you choose the best match for the particular battery that you currently have. With some searching you should be able to find the owner guide for your battery brand/model.

Most often you'll find that recommended absorption charging for AGM is 14.4V. You'll find differing float voltage recommendations but usually 13.2V or 13.6V. I'm a fan of 14.4V charging and 13.2V float.

Those particular Tripp Lite units are timer based and lack temperature compensation. They'll do an OK job (far from excellent) if the battery bank is smaller like 200Ah or so. If you want much better care then you move up to a charger that lets you program the specific voltages your batteries need. You'll be able to set the amps in bulk mode, the end of the absorption phase will be based on current flow (when the batteries are actually full) and not a timer and it will have temperature compensation.