Lithium batteries killing appliances?

[daleyocum]

We’re on our maiden voyage with our new Victron solar/lithum setup. This uses Battleborn lithium batteries with the vendor recommends bulk charging at 14.5 volts. So far so good. We have 300ah of lithium and 500w of solar.

Yesterday our new Atwood water heater blew out it’s controller and won’t lite on propane. In looking at the manual they make a point of saying the voltage should not exceed 14v. I’m wondering what other appliances, like the fridge, might be voltage sensitive like this. Have folks with Lithum noticed odd occurrences of electronic things breaking? Was this just coincidence?

I’m thinking about putting a 100A silicon diode in series with the line feeding the fuse panel to both drop the voltage down .6-.7v. That would save a little energy by not running the fans, lights, etc higher than they were designed for and keep everything below 14. Even when down to 50% state of charge I’m still seeing about 13.1 volts so the .6 v drop will still result in more than 12v.

Thoughts?

[uncle_bob]

Hi

While I know nothing about the Atwood, I can say that everything in a 2017 Classic other than the LED lights will survive 24V on the 12V lines. Since very standard "multistage" lead acid chargers will go to 14.6V, it's very doubtful that the Atwood stuff blows at that point. It's a rare piece of 12V gear that isn't good to 15.5V.

Bob

[A W Warn]

Originally Posted by daleyocum

We’re on our maiden voyage with our new Victron solar/lithum setup. This uses Battleborn lithium batteries with the vendor recommends bulk charging at 14.5 volts. So far so good. We have 300ah of lithium and 500w of solar.

Yesterday our new Atwood water heater blew out it’s controller and won’t lite on propane. In looking at the manual they make a point of saying the voltage should not exceed 14v. I’m wondering what other appliances, like the fridge, might be voltage sensitive like this. Have folks with Lithum noticed odd occurrences of electronic things breaking? Was this just coincidence?

I’m thinking about putting a 100A silicon diode in series with the line feeding the fuse panel to both drop the voltage down .6-.7v. That would save a little energy by not running the fans, lights, etc higher than they were designed for and keep everything below 14. Even when down to 50% state of charge I’m still seeing about 13.1 volts so the .6 v drop will still result in more than 12v.

Thoughts?

I have Boondocker converters in both of my trailers (the first one is 4+ years old) that charge at 14.6 volts at times. I've had no issues with my Atwood water heaters, or any other low voltage device.

add edit:
I think there is a thread on this forum that discusses a bad batch of Atwood control modules, that some have replaced multiple times.

[OTRA15]

Here is one of those threads about bad Atwood boards:

http://www.airforums.com/forums/f295...er-179320.html

See also these search results:

https://www.google.com/search?q=atwo...=airforums.com

Good luck,

Peter

[SilverHouseDreams]

As others mentioned. Check the other thread, order a Dinosaur board. Pester AS for reimbursement under warranty...otherwise consider it less aggregation than repeating the lack of hot water and trips to a dealer after every use of the trailer (based on the many that have had the issue here and elsewhere).

[daleyocum]

Originally Posted by SilverHouseDreams

As others mentioned. Check the other thread, order a Dinosaur board. Pester AS for reimbursement under warranty...otherwise consider it less aggregation than repeating the lack of hot water and trips to a dealer after every use of the trailer (based on the many that have had the issue here and elsewhere).

Thanks everyone. I’ll look into getting a Dino board a shipped to the RV park we’ll be staying at shortly. The AS dealer we’ll be visiting tomorrow will likely just fix it with another Atwood board. At the least I’ll try to not get one of the dreaded -8E batch boards.

[VaTravelers]

I think you are experiencing what many of us have in the newer trailers. We went through two Atwood OEM boards before we went to the DINO board. It works like a charm.

[daleyocum]

With all this advice in hand we made a special point to swing by the Airstream dealer in Seattle on our way up into the Cascades. They replaced the board with the offical Atwood board as would expect they’d have to but they knew all about the Dino board. They volunteered to call around and find one locally for us to go get while they replaced the board and did some other odds and ends. They didn’t want us to be stranded in the back country with cold showers anymore than we did! They found one which we went and got about 20 min away so now I’m all set.

I’ll probably just replace the board when we settle in a place for a few days just so it doesn’t fail at an ackward time.

Thanks everyone!

[OTRA15]

Thanks for the update, have a great trip!

Peter

[sgschwend]

Could you also change the programming of the charger. If you lower the final charge to 90% charge the battery will last a lot longer.

[daleyocum]

Originally Posted by sgschwend

Could you also change the programming of the charger. If you lower the final charge to 90% charge the battery will last a lot longer.

My theory going into this was it was the initial 14.5 bulk charge that was killing the board. It may still be the case that these higher charging voltages, lithium or no, are what’s causing the poorly designed Atwood board to go toes up. The manual says 14v is the absolute max. Or it may be something unrelated to voltage that’s causing them to die. Now that my Dinosaur board is installed I don’t care.

What amazes me is that Atwood hasn’t done anything about this even though they must know full well the boards need a fix. It also amazes me Airstream hasn’t told them to fix it or else.

Why is there a big enough market for replacement boards that Dinosaur finds it profitable to make these?

[SilverHouseDreams]

It would be a massive failure to engineer anything to go into a 12VDC system with a max voltage tolerance of 14.0VDC. Every alternator made for the last several decades puts out over 14.0VDC during some point of the cycle after startup...so they expect you to never use the charge circuit on a TT and to never have a charge bridge from the start battery to house batteries in an RV?

There is likely nothing that would exclude Atwood from a class action lawsuit over something like this.

[steverino]

As well, even though the OEM converters do not have an equalization stage, there are plenty of solar chargers, and/or converter upgrades, which do. In equalization mode, the charger will apply 14.7-15 volts periodically. I never experienced a failure on my 27FB with that, nor have I heard of any. Hopefully your experience was due to a bad batch, or other atypical situation that will not bite again!

[uncle_bob]

Hi

The stock solar converter that goes into any "solar" AS runs up to ~14.5 on a regular basis. I'll go higher if it's cold in the trailer and the temperature compensation cuts in. There are *lots* of trailers out there with that upgrade and that controller.

Bob