I dry camp exclusively. That said if I let my batteries deplete down to 20-30% I can end up with 3-4 hours of charge time on the generator. At some point I may add solar, but one of my favorite spots is super shady so that would not help. I think my current setup allows for roughly 100 amps/hr of charging.
600 AH of lithium
Magnum Inverter
(08-12-2023, 09:48 AM)360 Wrote: [ -> ]I dry camp exclusively. That said if I let my batteries deplete down to 20-30% I can end up with 3-4 hours of charge time on the generator. At some point I may add solar, but one of my favorite spots is super shady so that would not help. I think my current setup allows for roughly 100 amps/hr of charging.
600 AH of lithium
Magnum Inverter
If the question is can you charge the batteries faster?….I think the answer is no. Sorry.
Your charger (I believe) has a charge capacity of 125 Amps DC. Since you have 600 Amp hours worth of batteries, it will take 600/125 = 4.8 hours to charge fully depleted batteries.
If you could trickle some charge into the batteries using solar that will help…but like you said…only if you have sun.
Another approach would be to add additional batteries.
Finally, it would also pay benefits to understand what is using your battery capacity. The HH water pump is a huge draw. So would any heaters. I am not sure what the AH water heater draws when you are diesel, but it is definitely something.
If there is a better way of thinking about this…(especially for those that have lithium setups)…please chime in.
You could get an upgraded alternator for the generator and use a wakespeed external voltage regulator.
My victron charges 140amp and alternator charges 160amp at same time.
Wakespeed talks to victron bms
David
The answer is YES, you can add chargers. I added a PowerMax PM3-120LK to the lithium bank for faster charging. It is adds an extra 100A and cuts the elapsed time down. As the battery voltage comes up, the ampere rate declines so don’t expect 120 from the Victron and another 120 from the PM. Generally, the charger rate at adsorption, is 120A total whereas it would be considerably lower with just the Victron inverter/charger.
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Hello Gordon,
Where did you pull your 120 from for the charger?
Brad Aden, how many hours does it take you to deplete the 600ah battery down to 20% of capacity?
(08-13-2023, 12:01 PM)TJ Clark Wrote: [ -> ]Brad Aden, how many hours does it take you to deplete the 600ah battery down to 20% of capacity?
That is a great question in that I’m not sure. Overnight running my cpap, fridge and maybe the TV for a bit I will get to 30-40%. But I don’t know that actually means 30-40% of actual capacity or if that means I’m 30-40% of the cutout parameters that were programmed.
What I need to do on my next trip is to see what I’m actually using overnight by setting the counter on the inverter to track what I’m actually using vs. purely looking at SOC percentages. I meant to do it last time and had another gremlin that had my attention.
And Gordon,
While you are typing. I understand that you don’t get a full 120 and 120 as the batteries begin to top off.
What do you get when they are at 30% approximately?
And what parameter are you using to tell the inverter/charger to stop charging? Time, volts, SOC, or return amps?
Steve: there was a three wire ten gauge branch circuit to feed the old Freedom inverter. One leg fed the inverter pass through xfer switch to supply an output if not inverting, the other leg fed the charger portion.
The Victron uses only one 30A 120V supply and reduces the charge rate by whatever is being used by the output load. That left the old charger leg unused. I inserted a buss fuse holder in order to feed the new charger at 20A and ran a 12 gauge cable into the battery bay.
Richard: I rarely get to 30% SOC however, at 60% the BMS-712 (Victron SOC meter) reports 149A @ 14.0V during adsorption. I’m sure it goes a little higher during the bulk stage but I never seem to catch it. Both chargers are using a three stage algorithm floating out at 14.2V. I hope that answers your question.
It's important to know your c rating of your lithium batteries and it makes a difference whether they're in series or parallel. 300 amp hour battery with a 1C charge and discharge rating can discharge 300 amps in 1 hour and recharge 300 amps in 1 but I try to keep my charge rating less than .5 and my discharge rating less than .5. Hi current charge and discharge rates create a lot of heat and cause batteries to swell decreasing their potential.
Here is a chart with the values I use on my home solar and our class b setup.
Our class b that we built has one 525 watt solar cell, a 24vdc 200 AH lithium battery I built, daly BMS which is programmable with low temp protection. We have 2 victron mppt solar chargers, one for the 12v glass mat battery that runs lights and pumps the other is for the 24v lithium battery which feed the 1500w inverter, microwave, coffee pot, induction burner and 24v AC and heater. No charging from the coach.
We've gone a week without plugging in to shore power running the refrigerator full-time and all the other appliances one at a time. Yesterday was the first time we plugged in in more than a week we are in Monterey California where we haven't seen the sun yet.
I have edited this post as I realize much of it made no sense. Sometimes what you see in your head doesn't come out on paper so well.