LiFePO Battery install 2001 e825

#9

@Inwo How would I incorporate balancers? Hate to kill the cells if @chris1 experience is correct. I need to do some mechanical work to install before I can start charging, all in back seems pretty easy but I just know traction will suck.

#10

I dont see a problem with them in front.
You just connect one across each cell. No wiring needed.
If voltage goes over 3.55v it puts a .5a load on that cell.
Up to fully charged 3.5v they do nothing. Its an easy way to monitor voltage. An led comes on when battery is full.

#11

I also will need one or more jumper bars once I get into it this weekend. Will let you know and also go for a set of balancers, can you send a picture?

#12

Hey that’s a cool install. I like the fact that your re distributing the weight right back where it came from stock. That’s cool.

Question: if you were to fill all the stock battery compartments with Lipo what kind of Amp Hr system would you end up with??

#13

Sorry, shop is closed, math function turned off, :roll_eyes:search for the battery here, Dave posted specs on the cells. In packs of 5 or 10 a while back.

Will send more images as I go, those batteries are sitting on a piece of 2x4.

#14

Shop Closed, Math Function turned off LOL that’s a good one! When you get around to it, fingers crossed you will be up at 96volts

#15

Yes I figured about 92+ volts.

Amp hours gets trickier as it seems multiple ways to express.

Was hoping you would know. I look at a Trojan spec sheet and it lists various AH ratings across time.

Most others seem to only pitch a single AH figure without referring to time.

What is fair?

#16

The c/20 ah rating only applies to lead . Your cells are rated @ 60ah but they all have tested in the 70ah range. On a factory Deltaq i used #13 for a 25 cell install (gel setting) If your doing more then 25 you need to reprogram your charger

#17

I had 15 in the front like yours. Under load the #15 battery had excessive draw when hooked up to the 6 foot cable that ran to the second string of batteries under my rear seat. Dave said he had a problem like that once before with a 3 foot cable. Not sure if mine was a fluke or not. So i moved all batteries to the rear, I didnt feel much if any of a difference in handling. Those batteries weigh a fraction of what a lead acid does.

If I was to do this all over again, I would skip the BMS and go with Dave’s stand alone boards. Top charge with Mike’s suggestion, ICharger X6, then let the boards do their thing along the way. The BMS is nice to view each cell though…:man_shrugging:

#18

@chris1, thanks. It seems like such a good location. The #15 was the first cell in the front pack that connects to the rear ones?

I think I will try and then watch that cell. Also getting the balancers from Dave to be sure.

@kinghappy. Mike this is what Dave believes is on my charger. I don’t see #13 listed. Once I install will carefully monitor using current #3 setting. It seems if that isn’t working will try the DEKA gel setting.

Back to work.

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#19

#6 is the same as number 13 in a gem . That one worked well

#20

Ok, install is done, best news so far dash is still on and, it started charging as soon as I plugged in.

All in all pretty simple, just drilled a few holes up front to catch the angle stock clamped around the three pack. You could kit the parts pretty easily if there were others wanting to do this. I used SS band clamps around the three pack to make it monolithic as well as to tie the two rear cells together and to the frame. Used a bit of closed cell foam 1/2” thick between the rear cells and the frame. The one short jumper bar fit perfectly to connect the two packs, I used some foam here to double insulate.

@Inwo should I presume my lowest capacity cell is the one starting out at lowest voltage? They range from 3.107v to 3.204v. I will charge for 4 hours and check. My QuickQ is a 72v charger, how does it get the pack to 92.5v?

@kinghappy, how long do your packs take to charge, and once charged do you leave connected to A/C or unplug?

Is there any other maintenance or tricks I should be aware of using them?

@chris1 going at this having heard you loud and clear, for the traction benefit I am willing to see what happens splitting the pack. I will pay particular attention to each cell on either end of long lead for a bit.

One thing the front location allowed was to move Master switch up front. It was needed to lengthen the positive lead. Never understood hiding it under the seat.

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#21

87 volts, 3.5v/cell, or even 3.4v per cell is near full.
The 3.7 is absolute max if balanced, but could be way too high.
Find the first cell that goes high, if it’s been charging 4-5hrs at 12a they should all have 60ah in them.
The ones that are not as high have slightly more capacity, but range is dictated by the smallest cell. No need to put more into the rest after one is full. IMO.
@kinghappy has a different and possibly better method of filling them all and letting them empty at different times. Try this first. KISS
I ship them empty. A good place to start.
Such a clean install, a shame to connect balancers and mess it up. :slight_smile:
Besides, this is my only hope to get @Old_Houseboater on board. He will only go for a drop in swap.

#22

Went out, measured a few including the low cell and it was up to 3.3 so I gave it a test ride.

Folks, it’s been said here before by smarter people voltage makes all the difference. Excited at the torque.

It is definitely a drop in, with a screw gun and self threading fasteners needed to anchor. Some make a clamp kits and you are done. Moving the kill switch made hookup simple.

Back on charger and in an hour or so will record all the voltages again. Will not leave plugged in overnight.

@kinghappy how do you spoof the state of charge indicator? If only voltage it will always read high.

#23

packs take 6-7 hours depending on soc . the Deltaq will shut of after full so you can leave it plugged in .

i haven’t done a conversion on an early so i dont know how to sppoof the gauge . The lates you can adjust easily . There is also a voltage setting in the t4 and t5 to adjust voltage for display from 72v to 80v . I haven;t used it but if it exists in the early controllers try it

#24

Charger went to a steady green after about 6hrs. All were at 3.43 so algorithm #3 apparently won’t overcharge. I am going to drive a bit to see how this works.

@Inwo you mentioned balancers keep it at about this same level, maybe I don’t need to add with this setting. Wonder how much range I am leaving on the table? Would think it may make them last longer?

If changing the charger was easy I would try other settings but now gonna give it a few days of testing.

Thanks everyone

#25

The balancer does nothing below 3.55v.
The idea is piece of mind after you stop measuring daily.
It will also allow higher charging without worry.

#26

After work today, it had been sitting off charger (it went solid green last night and I unplugged).

All were at 3.330v except one at 3.331 and one at 3.329v.

Hard not to spin the tires now, lots of pep.

Very easy conversion. Will run a bit longer on current algorithm #3 and see how range goes. The dash battery indicator has not moved off 100% so that may be an issue to fix. Going to do a 10 mile r/t tomorrow to see how they hold up if it doesn’t rain! In LA in May…

#27

3.43 with a good saturation is probably 98% soc . i tested one that shut off @3.45 . it took less than 1 amp to get to 3.65 . These cells will always fall back to 3.33 after charging stops

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#28

We should keep these threads at the top. There are still discussions of lead battery care. As you know some need water, and all outgas with accompanying corrosion.
We need them to come to the light!:blush:

If I could ship lifepo4 with the shunts on them, it would be a safe drop in lead replacement. I could even cycle them first.