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Re: Li batteries

Reply #20 –
Not sure where you saw 50 amp charge rate being the max. Epoch website says 200amp charge rate. Unless you are referring to the victron Orion xs battery to battery which is 50 amps.

Re: Li batteries

Reply #21 –
Quote from: T and M Long –
Not sure where you saw 50 amp charge rate being the max. Epoch website says 200amp charge rate. Unless you are referring to the victron Orion xs battery to battery which is 50 amps.

Recommended 50 amp charge

Re: Li batteries

Reply #22 –
To optimize for a parallel setup, connect the house load to the positive terminal of the first battery and the negative terminal of the last. Alternatively, use equal-length leads connected to common bus bars. While uneven draw is a common concern, it is largely self-correcting; if one battery supplies more current initially, its voltage will eventually drop enough for the other battery to take over the load. Because of the flat discharge curve of LiFePO4 chemistry, this balancing process is gradual, but the batteries will naturally equalize over several cycles.

Re: Li batteries

Reply #23 –
I have a Balmar regulator so it will cut the charging down if the alternator gets too hot.

Re: Li batteries

Reply #24 –
I'm kind of late to see this, Bob, But I don't think Li batteries will meet your expectations so sticking with the gels may be your best .

Mike

Re: Li batteries

Reply #25 –
Quote from: Pamela & Mike –
I'm kind of late to see this, Bob, But I don't think Li batteries will meet your expectations so sticking with the gels may be your best .

Mike
Very late to the party here. Why would you think that Lithium would not meet expectations? What are the expectations? properly chosen and installed for House applications they are significantly better than Gell and even AGM in so many ways. How may I help?

Re: Li batteries

Reply #26 –
Thanks for everyone's help and comments.  A preliminary CCA test showed almost 1200 CCA in each battery. So for an addional more accurate capacity test my guru buddy lent me his MK branded discharge tester.  It puts a 25amp load on a battery and has a thumb drive input on its face plate to record results and has a panel display to show current in progress results.

When i stored the coach almost 3 years ago i went through what i thought would be a fairly reliable setup to keep the mk 8g8d gels fully charged without oversight or damage. 

Installed 3 365 watt LG panels into a midnight sun solar junction box running the wires without combining them all the way to the box so as to not have high voltage on the roof which i understood then may/should use conduit.  The collector box has inputs for 6 wires.  I am only using 3.

From there its combined input goes to a magnum energy pt-100 solar controller which is networked into my MS 2812 inverter/charger with a ME-ARC remote panel.  I added a BMS with a temp shunt to adjust the charging voltage to the batteries actual temperature.

To maintain the engine batteries S0C I added a blue seas ACR to connect under charging and disconnect under discharge.

When I finally went to the coach everything started perfectly.

Voltages showed correct.  So i turned on the inverter and turned on the convection microwave sharp oven that Richard Bark had added to the coach before we acquired it. 

Voltage dropped to under 12 in 20 seconds or so and the inverter kicked out under the load.  So my preliminary thought was that the batteries had lost capacity during the storage.

Turns out that they may well be ok. 

I still have the dometic rm7832 refer in the coach.  No residential refer. So the 332 amp hours capacity at 50% DOD may still be available. 

If after testing i still have a large percentage of the original capacity of the mk gels I may keep them as they were new 5 years ago and have not been cycled much.

The epoch li-ion install may/would  require a new ME ARCL panel if i wanted a preset battery profile for that type.  Versus a custom profile on my version 4.0 ME-ARC remote panel.  Magnum also offers a MS 2812L version of my inverter/charger which has a board change in it for a dedicated li-ion use.  Maybe that is for stand alone maybe without  a remote panel use?

I have the time to use my buddies mk tester to verify actual condition of the gels. 

They may well be ok.  Testing will tell.

The Foretravel family i first had contact with in 1984 is still here i see.  Pleasure to see the newer crowd is in many ways the same good people i knew from FTX and Travco days. 

https://www.mkbattery.com/application/files/8415/3374/5183/MK_70_CAPTEST_User_Manual.pdf
 

Re: Li batteries

Reply #27 –
Quote from: BobN –
To optimize for a parallel setup, connect the house load to the positive terminal of the first battery and the negative terminal of the last. Alternatively, use equal-length leads connected to common bus bars. While uneven draw is a common concern, it is largely self-correcting; if one battery supplies more current initially, its voltage will eventually drop enough for the other battery to take over the load. Because of the flat discharge curve of LiFePO4 chemistry, this balancing process is gradual, but the batteries will naturally equalize over several cycles.

I have equal length cabling with the gels currently.  End of string positive in my experience caused the end batteries to lose more capacity. 

I initially looked at li-ion when liberty was using Northstars in their bus conversion.  $6k each and limited capacity and the inherent temp restrictions then made them a reduction in the U 320's coaches true four season usefullness.  I have gone many times over the high temp limit at the Colorado river and have motorhomed skiing at minus 25F(long ago).  Summer road temps would exceed the li-ions ability to accept charge at times.