Client Success Story: Upgrade to Lithium Battery Without Tossing Out the Lead-Acid Ones

After revamping his old off-grid solar system with us, Chris was ready for the next step in his journey toward energy independence. 

During phase 1, we increased his solar production by adding eight utility-grade solar panels and a solar charge controller (SCC). The upgrade solved his immediate challenges and added resiliency, but not enough to bring his system to the ideal state.

While the solar array generated up to 2,000W daily, the production wasn’t always enough to meet the power needs during the day and top off the existing lead-acid batteries. As a result, the batteries continued to deteriorate, and the fuel tab for the generator stayed eye-watering.

A strategic approach to off-grid solar system upgrade

We have set the stage for subsequent upgrades in phase 1 with a modular design that allows us to add components to the system without reworking anything.

Phase 2 saw the addition of 16 utility-grade solar panels to the array. We calculated the property’s solar trajectory and helped Chris position his solar field to optimize production based on his lifestyle and consumption pattern (e.g., using air conditioners during late afternoons in the summer.)

We also added two new SCCs to the system to handle the increase in solar production while providing extra resiliency — the system can still maintain decent power output even if one solar panel string or SCC runs into issues.

Chris building his new solar field based on our solar trajectory calculation.

The substantial boost in solar production means Chris has more power than the existing lead-acid battery bank can absorb. Thus, it makes sense for him to add more battery capacity to store power for the night and reduce generator use — leading us to the focus of this project: Transitioning from lead-acid batteries to lithium ones without the added costs and complexity.

They say, “You can’t mix lead-acid and lithium batteries.”

We say, “Hold our beer.”

Before talking to us, Chris was in a pickle with his battery situation. He just spent ~$5k on a new lead-acid battery bank about 12 months ago. The batteries were deteriorating, but not so bad that they require a complete, $5k replacement (Ouch!)

If Chris were to upgrade to lithium batteries, conventional wisdom says he would have to toss out $5k worth of deteriorated-but-still-working lead-acid batteries and replace them with new lithium ones. Alternatively, he would have to put up with the poor-performing battery bank and see the generator fuel cost go up the roof until he can’t take it anymore.

The options were either costly and wasteful or costly and painful. However, Chris can have his cake and eat it, too. Our proprietary technology enables us to mix battery cells of any chemistries and ages. As such, we can add lithium batteries to the existing lead-acid battery bank to increase storage capacity without tossing out the lead-acid batteries.

We proposed a stepped approach to the battery transition:

Step 1: Adding one 4 kWh custom-built high-endurance lithium iron phosphate (LFP) battery to augment the capacity of the existing lead-acid battery bank. We program the battery management system (BMS) to discharge the lithium battery before the lead-acid ones to extend the lead-acid pack’s lifespan (possibly by 2-3 years).

Step 2: Adding one more 4 kWh custom-built high-endurance lithium iron LFP battery to increase storage capacity, minimize generator use, and further preserve the lead-acid batteries.

Step 3: When the lead-acid battery bank ages out, we’ll add lithium cobalt batteries to the mix to ensure an uninterrupted power supply during cold nights and mornings.

Our custom battery pack (blue) plays nice with the old lead-acid battery bank (red).

Transitioning from lead-acid to lithium batteries without the high cost and complexity

Our propriety battery technology and phrased approach enable us to help our clients squeeze as much out of their existing lead-acid batteries as possible while adding a modern battery solution to (1) boost power storage capacity and (2) transition to a maintenance-free long-term solution with a lower total cost of ownership.

Learn more about our lead-acid cure and battery solution, and get in touch to see how we can help.