Electric Truck Lithium Battery Upgrade

by Ben N on August 10, 2019

Click to watch the video.

I upgraded the Electric Ford Ranger to Lithium Batteries!
The truck had Group 24 Lead-Acid batteries in the bed. The batteries pulled from the Smith electric truck are Valence brand Group 27 batteries designed as 12V replacements. So, the logical thing to do was simply pull out the lead and put in the lithium in it’s place!

Overall, it was a pretty easy upgrade. Just remove the cables, remove the old batteries, put in the new ones, and cable it back up.

(DISCLAIMER! WORKING WITH HIGH VOLTAGE DC IS DANGEROUS AND POSSESSES SIGNIFICANT SHOCK HAZARD INCLUDING DEATH. DON’T DO IT UNLESS YOU KNOW WHAT YOU ARE DOING!)

Lithium batteries in the back of the truck.

Replacing the batteries was pretty straight-forward. The toughest part was keeping polarity straight and making sure I didn’t have to move the batteries more than once. Going from the Group 24 size to Group 27 size meant a slightly different configuration. Not a big deal, but any change meant I really had to pay attention to polarity and make sure I had enough of the right length cables. I re-used the cables from the Smith electric truck battery pack, and had just enough of the right types without having to replace any terminals.

STILL IN THE BED
The batteries are still in the bed. The main reason for that is that I’m still experimenting and want to have full access to the batteries. This truck has a battery box, roughly the size and shape of a coffin, that runs UNDER the length of the vehicle. It’s a slightly irregular shape and would have contained the original 8V lead-acid batteries this truck was designed for. The height of the box is higher than the road clearance, so just to get it off, a person needs to lower the box while simultaneously lifting the truck!

Because of the irregular shape of the box, it’s unlikely that the Valence batteries will fit inside. Some other DIY’ers have used Nissan Leaf batteries in Ford Ranger EV upgrades, and those cell modules are only about 1.25 inches thick each. They are easy to repackage into a more custom shape, including one that would fit in the original battery box.

Valence BMS unit.

BMS
After connecting the power cables, I also daisy-chained the BMS cables from each battery to the next. They end at the BMS which I repurposed from the Smith truck battery box. But there’s a few shortcomings to this. I do NOT have any kind of an interface to the BMS to pull data from it. (No dongle, no software!) Also, the Smith battery was 24 batteries in series, and the Ranger uses 26. So, I connected the BMS to the truck, but excluding those two extra batteries.

Lastly, the BMS would have been integrated to the charger, and on the Ford, it isn’t. I’ll do bulk charging only and stay away from the top end of the battery pack.

It DOES look like the BMS WILL automatically BALANCE the batteries simply by being connected without any other changes.

WEIGHT SAVINGS
The truck did shave off a few pounds with the lithium upgrade. Each of the original Group 24 Lead-Acid batteries weighed 60 pounds. The Group 27 Valence lithium batteries weigh 43 pounds each. When swapping out the batteries, I saved about 442 pounds.

Inside the Valence batteries are cylindrical cells. Think something along the lines of 18650s. Because of this, they don’t give AS GOOD of a weight savings as some other types of lithium batteries. (On the other hand, they don’t start on fire, either!)

These batteries weigh about 2/3rds of the lead-acid equivalent while having significantly more capacity.

CAPACITY AND RANGE
The batteries are rated at 138AH capacity, and there are 26 of them. At 12.8V nominal, that’s almost 46kWh of energy! Of course, that’s if using the entire battery, and brand new. These batteries ARE used. In testing some samples, it looks like they are at about 85% capacity of new, bringing pack capacity to less than 40kWH. That’s still far more than a gen 1 Nissan Leaf!

However, I don’t guess that the truck is very efficient. It’s relatively heavy and trucks aren’t know for their aerodynamics. As a best guess, I would say it uses 400 wh/mi. But if the pack really is 40kWh, that means I might have a 100 mile range!

The truck, ready to do some long-distance joy-riding.

TEST DRIVING
After a fresh charge, I took the truck out, first taking it to a local car show. That was a blast, there was ton’s of interest in the Ranger EV, and nobody knew how Ford has ALREADY built electric trucks! (Too bad I didn’t remember to grab a photo until after the car show was over. I had quite a mob for a while!)
The rest of the day, I did errands and some other driving bringing my distance driven to 40 miles.

The next day, I went out for some joy-riding to see how far I could keep going. I tried staying not too far from home, in case my range was shorter than I thought!
I started snapping photos of the trip odometer. 65 miles was sort of a milestone. My 2012 Mitsubishi iMiEV electric car is only designed for about 60 miles per charge. I now had a 1996 electric vehicle with better range than a 2012!

I kept driving, and the truck just kept going. The “Range Remaining” gauge only goes up to 60. I believe that it works off a combination of battery voltage AND an AH counter. Unfortunately, it’s not very accurate for lithium. I used the New Generation Star Tester to track the pack voltage vs the voltage discharge chart of the Valence batteries. That seemed to give me a fairly accurate representation of available charge.
I kept driving and got 70, 80, 90, yes, even 100 miles!
After that, the voltage was dropping fast, indicating I was getting down into the last 10% of the battery.

J1772 ADAPTER
Next, I’d want to be able to do some charging in public. That would further extend my range. To do so, I built a J1772 adapter so that I could keep the truck stock, but still use modern public stations. I’ll post more about this adapter soon. (I could SWEAR I already shot a video on this!)

WHATS NEXT?
I definitely want to do some towing with the truck. Having the batteries in the bed is less than ideal, but does make it great for experimenting. Just having a battery pack this big could be useful for things like running an inverter for emergency power backups.

I still need to finish up the BMS system. It’s not integrated with the charging system yet.

It’s been fun to play around with a 20 year old factory built electric. Other than the original LACK of lithium batteries, it’s pretty modern, with regenerative brakes, electric heat and air-conditioning. The instrumentation is a bit lacking. If a person didn’t know better, they’d look at the steering wheel and dashboard and think it’s just any truck!

I’m looking forward to Ford coming out with a new all electric F-150. But who knows exactly when that will happen. Meanwhile, I’ll keep driving MY electric Ford!

Until next time, stay charged up!
-Ben


{ 2 comments… read them below or add one }

1 Mike August 10, 2019 at 11:33 pm

You can use a rs485 cable and read each battery with software. It also allows you to change module # and see soc, cycles, balancing of each battery. I sacrificed one of the bms extension cables from one of the battery pods and wired it to rs485 cable. Keep up the good work ben.

2 admin August 11, 2019 at 10:13 am

Thanks Mike,
Do you have a copy of the software you could share?

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