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 > Lifepo4 battery in 1990 Lance?

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FWC

The Wilderness

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Posted: 01/11/21 12:41pm Link  |  Quote  |  Print  |  Notify Moderator

At 13.6V you will get somewhere between 95 - 99% charged. The question would be what is the *actual* voltage your converter is putting out?

Either way, if you are upgrading to a lithium battery it is probably worth upgrading the charger even if it is not strictly necessary.

3 tons

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Posted: 01/11/21 05:32pm Link  |  Quote  |  Print  |  Notify Moderator

FWC wrote:

At 13.6V you will get somewhere between 95 - 99% charged. The question would be what is the *actual* voltage your converter is putting out?

Either way, if you are upgrading to a lithium battery it is probably worth upgrading the charger even if it is not strictly necessary.


Thanks for providing a sentient response!!

In fact LiFePo4’s don’t require a full charge except for an occasional BMS cell-rebalancing, and of the reputable drop-ins I’ve seen, DOD’s are often rated at a full 100%...This is likely the basis of the OP’s inquiry rather than of SiO2...JMO

3 tons

steveh27

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Posted: 01/12/21 04:45am Link  |  Quote  |  Print  |  Notify Moderator

When I replaced the 105AH lead acid battery in my Class B, with no space for 2 batteries, I contacted a lifepo4 manufacturer in China that advertised on Amazon. I gave them the size of my battery box & they built 2 100AH LiFePo4 batteries which fit. So I went from 50 usable amps to up to 160. I never drained the lead acid battery to 50% only 60%, and I do not expect to drain the LiFePo4's to 20%, but it is nice to have that capacity.

They had me buy them through Alibaba for a lower cost. Prices have come done since I bought in 2019.

I contacted Power Dynamics re my charger and they said only to push in the boost button to get the max charge.

StirCrazy

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Posted: 01/12/21 05:50am Link  |  Quote  |  Print  |  Notify Moderator

BFL13 wrote:

Understand the "density" point. BUT--we are talking about "space" for one battery in the battery compartment. The SiO2 27 is a 27. You can run it down to a low SOC no problems so you can have more AH in the same 27 space, which is what the OP wants.

I don't know the true story about Li charging, but I suspect others will want to comment on using a 6300 converter for that. Should be interesting! [emoticon]


and the same ah in LiFeO4 is about 1/3 the size. so for a limited battery space the Li is the better choice. also a lot lighter for the same AH capacity.

Steve


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StirCrazy

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Posted: 01/12/21 05:56am Link  |  Quote  |  Print  |  Notify Moderator

jaycocreek wrote:

Will putting a 100ah Lifepo4 battery in a 1990 Lance with a single battery compartment work right?(picture below of converter/charger)It would basically double my house capacity from my currant Group 27 lead acid..

Will this work and charge completely..I think the answer to charging is it will not charge completely, but I am asking..

What issues would I have or would I?

Would I be better to use it as a standalone battery with a charger for Lifepo4 batteries?

[image]

Recommendations?


first thing is you will have to upgrade your power centre, are you handy? I did this in my 1991 slumber queen, went from the old glass fuses to a moderen intelli power power centre that has a jumper for Li batteries. I did go the lead acid bateries as I counverted the storage compartment into a battery compartment and was able to fit two GC batteries. if I would have realized how cheel the LiFePo4 cells have gotten I would have ordered 8 280ah cells and a BMS and put togeather my own 560AH battery for the camper that would have fit in the original battery box. but if your not handy that way battle born type set up is the next best option for saving size and weight. with the cell advancment these days you could probably get a much higher ah capacity than 100 to fit in there.

Steve

BFL13

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Posted: 01/12/21 09:50am Link  |  Quote  |  Print  |  Notify Moderator

StirCrazy wrote:

BFL13 wrote:

Understand the "density" point. BUT--we are talking about "space" for one battery in the battery compartment. The SiO2 27 is a 27. You can run it down to a low SOC no problems so you can have more AH in the same 27 space, which is what the OP wants.

I don't know the true story about Li charging, but I suspect others will want to comment on using a 6300 converter for that. Should be interesting! [emoticon]


and the same ah in LiFeO4 is about 1/3 the size. so for a limited battery space the Li is the better choice. also a lot lighter for the same AH capacity.

Steve


Must be a typo or something there?

A Walmart G27 is 12.65 x 6.9 x 8.94 inches and 49 lbs
A Relion 100AH LFP is 13 x 6.8 x 8.9 and 32 lbs
A Trillium 111AH LFP is 12.07 x 6.57 x 8.63 and 30lbs
A Stark 105AH AGM is 12.9 x 6.8 x 8.7 and 66 lbs
An SiO2 100AH is 12.28 x 6.72 x 8.6 and 60 lbs

Another thing about battery compartments in RVs is their odd shapes and any pipes or whatever in them, so battery orientation could determine how many you can get in. Some you can put end up or not, or just on their sides, but none upside down

Allowance for wiring needed too--stiff wires can't be bent in much--it all depends.

LFP "roll your own" needs a box and keep the cells tight so no vibration, lots of wires and a BMS. I dont know what that takes for volume or shape as to what would fit in the OP's battery compartment--he would have to figure that out.

Also he needs room for the heat pads and whatever wiring they take with LFP.

On that 6300--I would toss that whatever kind of battery. In the MH I kept the 6300 panels and swapped out the charger for a PowerMax modern type. The TC original charger was gone and the prev. owner used a portable charger. I tossed that and use a deck mount PowerMax converter in there.

The OP has a 32 amper for the TC which is ok for a 100AH batt, but if he gets more AH, more amps of a charger would be good. Depends on the battery charging spec. 30% charging rate is max for AGMs and SiO2s, eg.
LFP can take way more.

You have to juggle the charger size in amps with the size of the portable gen you can take along to run the charger. That is my limit in the Class C. Can't carry a 3000w gen, but can carry a 2200, so 75 amps is my limit for a charger. The OP has to figure that all out for his own rig as to what is possible.


1. 1991 Oakland 28DB Class C
on Ford E350-460-7.5 Gas EFI
Photo in Profile
2. 1991 Bighorn 9.5ft Truck Camper on 2003 Chev 2500HD 6.0 Gas
See Profile for Electronic set-ups for 1. and 2.

FWC

The Wilderness

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Posted: 01/12/21 11:20am Link  |  Quote  |  Print  |  Notify Moderator

If the OP is limited to exactly a Group 27 size, then 120Ah is about the biggest drop in Lithium that will fit. But more likely there is some wiggle room, meaning a 150Ah will probably fit.

But if we are going to make the claim that SiO2 has higher 'usable capacity' than AGM or flooded because of a higher number of cycles at a given depth of discharge, then the same logic holds true for lithium. Lithium supposedly gives 3000 cycles at 100% DOD. An apples-to-apples comparison would imply that supposedly you can only use your SiO2 to 50% DOD to yield the same lifetime. I am not saying I necessary agree with this sort of comparison, but if you are going to make them, they should be consistent.

BFL13 wrote:

StirCrazy wrote:

BFL13 wrote:

Understand the "density" point. BUT--we are talking about "space" for one battery in the battery compartment. The SiO2 27 is a 27. You can run it down to a low SOC no problems so you can have more AH in the same 27 space, which is what the OP wants.

I don't know the true story about Li charging, but I suspect others will want to comment on using a 6300 converter for that. Should be interesting! [emoticon]


and the same ah in LiFeO4 is about 1/3 the size. so for a limited battery space the Li is the better choice. also a lot lighter for the same AH capacity.

Steve


Must be a typo or something there?

A Walmart G27 is 12.65 x 6.9 x 8.94 inches and 49 lbs
A Relion 100AH LFP is 13 x 6.8 x 8.9 and 32 lbs
A Trillium 111AH LFP is 12.07 x 6.57 x 8.63 and 30lbs
A Stark 105AH AGM is 12.9 x 6.8 x 8.7 and 66 lbs
An SiO2 100AH is 12.28 x 6.72 x 8.6 and 60 lbs

Another thing about battery compartments in RVs is their odd shapes and any pipes or whatever in them, so battery orientation could determine how many you can get in. Some you can put end up or not, or just on their sides, but none upside down

Allowance for wiring needed too--stiff wires can't be bent in much--it all depends.

LFP "roll your own" needs a box and keep the cells tight so no vibration, lots of wires and a BMS. I dont know what that takes for volume or shape as to what would fit in the OP's battery compartment--he would have to figure that out.

Also he needs room for the heat pads and whatever wiring they take with LFP.

On that 6300--I would toss that whatever kind of battery. In the MH I kept the 6300 panels and swapped out the charger for a PowerMax modern type. The TC original charger was gone and the prev. owner used a portable charger. I tossed that and use a deck mount PowerMax converter in there.

The OP has a 32 amper for the TC which is ok for a 100AH batt, but if he gets more AH, more amps of a charger would be good. Depends on the battery charging spec. 30% charging rate is max for AGMs and SiO2s, eg.
LFP can take way more.

You have to juggle the charger size in amps with the size of the portable gen you can take along to run the charger. That is my limit in the Class C. Can't carry a 3000w gen, but can carry a 2200, so 75 amps is my limit for a charger. The OP has to figure that all out for his own rig as to what is possible.


3 tons

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Posted: 01/12/21 11:43am Link  |  Quote  |  Print  |  Notify Moderator

steveh27 wrote:

When I replaced the 105AH lead acid battery in my Class B, with no space for 2 batteries, I contacted a lifepo4 manufacturer in China that advertised on Amazon. I gave them the size of my battery box & they built 2 100AH LiFePo4 batteries which fit. So I went from 50 usable amps to up to 160. I never drained the lead acid battery to 50% only 60%, and I do not expect to drain the LiFePo4's to 20%, but it is nice to have that capacity.

They had me buy them through Alibaba for a lower cost. Prices have come done since I bought in 2019.

I contacted Power Dynamics re my charger and they said only to push in the boost button to get the max charge.


I’m using the ‘standard’ Progressive Dynamics 9245 with added Charge-Wizard dongle used to kick the charger into it’s 14.4v Boost mode - Per the Victron BMV 712’s bluetooth-Smartphone detailed menu display’s, charging goes on without a hitch (very little internal resistance needed to overcome)...

Shortly after the (Li programmable) Victron’s 100% SOC ‘end of charge’ parameters have been met (e.g. V and A hold steady for a brief period...), you can watch as the Li’s internal BMS begins it’s sequential current and voltage cell-balancing dance, whereby cells of a higher potential will bleed any potential excess charge to sister cells of a lower potential, and where any remaining charge deficit is resolved via a final charger top-off (verifiable as voltage holds at a steady state and charge current stops).

Once cell-balancing is complete, there’s no real need to carry on with an active charger (this, contrary to conventional FWC charge objective - a kinda non-intuitive thingy - lol) in an attempt to maintain FWC’s traditional ‘holy grail’ of ‘on or near’ 100% SOC (recall, very little voltage sag throughout the entire Li discharge cycle)...So for this and for purposes of longer term storage I simply added a basic battery post-top disconnect switch which allows the converter-charger to carry on in it’s roll as a 12v RV power supply...

When charging, I only occasionally charge to a full 100% SOC, since cell-balancing is only necessary periodically - with it’s greater operating breadth, Li is quite happy somewheres in the mid range, even if running the air conditioner from inverter..

For longer term storage, the Li is happiest to hibernate along at about 50%ish SOC (cations and anions in approx. steady-state equilibrium), and not much monitoring is required due to Li’s uber low tendency to self-discharge...

Hope this helps the uninitiated!!

3 tons

BFL13

Victoria, BC

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Posted: 01/12/21 12:17pm Link  |  Quote  |  Print  |  Notify Moderator

I don't think I ever said an SiO2 could do as many deep cycles as an LFP.

If the LFP and SiO2 100AH batts are both operated to 80% of SOC range, then that is the same for AH. How often you can do that, and whether that is often enough is situational per individual RVer.

Battery types each have their own features for matching to your RVing needs. It is not a contest for saying one is better than another as such.
Which one works best in your situation is what counts.

FWC

The Wilderness

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Posted: 01/12/21 12:33pm Link  |  Quote  |  Print  |  Notify Moderator

I don't quite follow. Isn't this exactly the point you were trying to make? That SiO2 has higher capacity because it has more cycles at a given SOC?

If not, then no replacement battery has higher capacity, just use them all to 80% SOC and safe a bunch of money.

BFL13 wrote:

I don't think I ever said an SiO2 could do as many deep cycles as an LFP.

If the LFP and SiO2 100AH batts are both operated to 80% of SOC range, then that is the same for AH. How often you can do that, and whether that is often enough is situational per individual RVer.

Battery types each have their own features for matching to your RVing needs. It is not a contest for saying one is better than another as such.
Which one works best in your situation is what counts.


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