Atempower DC/DC

[RJ Howell]

Not knowing who has followed the conversation @dbhosttexas and I have gadabout his purchase of a Atempower multi-charger or not.. Thought I'd post it for others that may be thinking about something along these lines.

I purchased the Atempower AP30DC DC/DC Solar charger. I needed a replacement to my Renogy unit of same power.At just over $300 I decided to hookup my older system and wait the pricing out with Renogy.. Along comes DB and introduced me to this little Aussie power unit.

DB was concerned about it charging LiOn batteries and not LiFePo4. I read the spec's and it looked good to me and at 1/2 the cost.. I'll give it a go!

Nothing on my spec sheet even mentions LiOn batt's and everything here on mine states/works for LiFePo4. Cool!

Item for item, by spec's, it matches Renogy. Then it goes a bit further and adds an 'optional' ignition sensor. May not mean much to you, but if you wish to turn it off/on you can connect the wire. If not, then it works when ever your truck (main) battery is full automatically. That's cool.
Then it also has a temperature sensor, like all LiFePo4's should have, to shut down if too hot or cool.
Neither does the Renogy have at twice the price.

I'm not invested in the company.. even though it sounds it. I may just check if they're a public stock though..

Just saying looking like a good product, from folks that have been doing back country for some time now and have a clue how..

[bdosborn]

It will charge the Li-on batteries safely but I think performance depends on the li-on battery you have, the maximum cell voltage varies with cell chemistry.
https://en.wikipedia.org/wiki/Lithium-ion_battery#Voltage_limits

Voltage limits
Lithium-ion cells are susceptible to stress by voltage ranges outside of safe ones between 2.5 and 3.65/4.1/4.2 or 4.35V (depending on the components of the cell).

A charger for LiFePO4 will stop charging at 3.65V/cell * 4=14.6V. If the li-on chemistry wanted 4.2V/cell then the fully charge voltage would be 16.8V. So the best case scenario is the li-on battery would be charged fully (3.65V/cell) by the charger and the worst case would be the battery is always undercharged (4.2V/cell). I'd check the li-on battery specs and see what the fully charged voltage is before I committed to buying one for li-on.

Bruce

[RJ Howell]

Bruce, the Atempower runs the same voltage spec's the Renogy 30a unit as to LiFePo4. Best I see, Victron also has the same spec's. Both at nearly twice the money.

What are you using? for DC/DC charging?

[bdosborn]

I've go both, a Renogy in the trailer and a Victron in the Van. The Van has a smart charging system; the alternator voltage drops to 12.7V or lower when coasting for regenerative braking. It also maintains the starter battery voltage a little low to accept the regenerative braking current. The Victron has enough smarts to accommodate the wide voltage swings (but it took me awhile to sort out the setting). It's also much more efficient that the Renogy so it doesn't get as hot. Victron has a good support network, all though I haven't had to use it. Their support pages are a pretty good, the one issue I've had with the Renogy has been wrong in their documents for YEARS!

The Renogy is one step beyond junk (IMHO) but it's still working so I haven't replaced it. I use the trailer running lights to turn it on and off as it doesn't have any smart settings. When it dies I'll replace it with a Victron. I won't be buying any more Renogy stuff, the internet is littered with posts about their awful support.

Bruce

[RJ Howell]

Bruce, since you have a Victron in use then you'll be the second one I ask that owns and uses. Have you seen your 12v LiFePo4 over 14.4v? The other s told me they haven't. They first used the pre-set and probably like you switched over to manual settings. Still they never saw it charging over 14.4v.. Curious.

I didn't find the 30a Renogy ran hot, I will say the 20a unit seemed hotter. The 20a unit was ignition on (I set to lights) start, the 30a 'was' auto much like the Victron. The Atempower can go either way. I like the ignition on (lights for me) over the auto switching. Just me knowing for certain.

I don't find Renogy as junk, just baseline equipment at high pricing. When I bought both the Renogy's they were priced right.. Those days are gone and being nearly equal in pricing, I will agree that Victron has more to offer.

[MickinOz]

I have a Renogy charge controller. I'm very glad I didn't buy a Victron. The nearest equivalent Victron was smaller capacity and twice the price.
And no display, to boot.
If the Renogy is working, how can it be junk?
You get what you pay for, I guess.
Since I have discovered my energy use is so small I can just recharge when I get home, the Victron would simply have meant I wasted twice as much money.

[bdosborn]

Bruce, since you have a Victron in use then you'll be the second one I ask that owns and uses. Have you seen your 12v LiFePo4 over 14.4v? The other s told me they haven't. They first used the pre-set and probably like you switched over to manual settings. Still they never saw it charging over 14.4v.. Curious.

I had a single cell go too high using the stock Victron setting, it has a long absorption time that keeps the voltage at the charged voltage for an hour or so. While the overall voltage didn't go over 14.4V, a cell went over 3.65V. So I tweaked the settings: my charged voltage is 13.8V and the absorption time is 15 minutes. No more problems after that. Its probably not an issue with an all-in-one liFePO4 but I have a DIY battery that needs a little more attention.

Bruce

[bdosborn]

If the Renogy is working, how can it be junk?
You get what you pay for, I guess.

You're right, a lot of people are happy with Renogy. My problem is I'm too into this stuff so I need equipment with tons of options and cool displays. I'll be tweaking the vans electrical system for years, luckily Victron has a *LOT* of buttons.

Bruce

[RJ Howell]

Okay, so Victron does only go 14.4v as well as the Atempower, as I was reading and told. I also saw the absorption timing which I thought was weird.. Boost charge at at 14.2 (?) then absorption at 14.4v. I get why you play with settings.

Have to say surprised your balancer didn't catch the one cell not playing well. I also have a DIY LiFePo4 and a 'all-in-one unit. Personally I find my DIY runs better (better parts I figure). I've now built up a larger DIY unit in hopes of adding an induction cooktop for those rainy days or cold morning starts..

I've yet to find another multi-charger, at Atempower pricing and capability. That's the main reason I brought it up. It's another unit that should be looked at.

Safe Travels all!

[bdosborn]

Have to say surprised your balancer didn't catch the one cell not playing well. I also have a DIY LiFePo4 and a 'all-in-one unit. Personally I find my DIY runs better (better parts I figure). I've now built up a larger DIY unit in hopes of adding an induction cooktop for those rainy days or cold morning starts..

I have one wacky cell that balances just fine until you go over 13.8V then the voltage shoots up way ahead of the other cells. The cells were an Ali Express special so go figure.

An induction cooktop was my motivation for a large inverter and battery. We haven't used it for camping yet but during tests it works really well. You'll need a 3000W inverter to get full power out of the cooktop, my 2000W only lets me run it at 7 out of 10 power (but it still boils water in 3 minutes). I should have the kitchen installed in a couple of weeks so maybe well get to use it yet this year,

Bruce